Balluff LRP800 Passive Tag Reader LRP820/LRP830 User Manual C transfer 1269 LRP820vc vp

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OPERATOR'S MANUAL
LRP820-Series
Long-Range Passive
Reader/Writers
Manual Revision 3, July, '00
Publication #17-1269
Escort Memory Systems Warranty
Escort Memory Systems warrants that all products of its own manufacture conform to Escort Memory Systems specifications and are free from defects in material and workmanship
when used under normal operating conditions and within the service conditions for which
they were furnished. The obligation of Escort Memory Systems hereunder shall expire one
(1) year after delivery, unless otherwise specified, and is limited to repairing, or at its option,
replacing without charge, any such product which in Escort Memory System's sole opinion
proves to be defective within the scope of this Warranty. In the event Escort Memory Systems is not able to repair or replace defective products or components within a reasonable
time after receipt thereof, Buyers shall be credited for their value at the original purchase
price. Escort Memory Systems must be notified in writing of the defect or nonconformity
within the warranty period and the affected product returned to Escort Memory Systems
factory or to an authorized service center within thirty (30) days after discovery of such defect or nonconformity. Shipment shall not be made without prior authorization by Escort
Memory Systems.
This is Escort Memory Systems' sole warranty with respect to the products delivered hereunder. No statement, representation, agreement or understanding oral or written, made by
an agent, distributor, representative, or employee of Escort Memory Systems which is not
contained in this warranty, will be binding upon Escort Memory Systems, unless made in
writing and executed by an authorized Escort Memory Systems employee. Escort Memory
Systems makes no other warranty of any kind whatsoever, expressed or implied, and all implied warranties of merchantability and fitness for a particular use which exceed the
aforestated obligation are hereby disclaimed by Escort Memory Systems and excluded
from this agreement. Under no circumstances shall Escort Memory Systems be liable to
Buyer, in contract or in tort, for any special, indirect, incidental, or consequential damages,
expenses, losses or delay however caused.
Equipment or parts which have been subject to abuse, misuse, accident, alteration, neglect, unauthorized repair or installation are not covered by warranty. Escort Memory Systems shall make the final determination as to the existence and cause of any alleged defect.
No liability is assumed for expendable items such as lamps and fuses. No warranty is made
with respect to custom equipment or products produced to Buyer's specifications except as
specifically stated in writing by Escort Memory Systems in the contract for such custom
equipment.
This warranty is the only warranty made by Escort Memory Systems with respect to the
goods delivered hereunder, and may be modified or amended only by a written instrument
signed by a duly authorized officer of Escort Memory Systems and accepted by the Buyer.
Extended warranties of up to four years are available for purchase for most EMS products.
Contact EMS or your distributor for more information.
This document contains proprietary information which is protected by copyright. All rights are reserved. The information in this manual has been carefully checked and is believed to be accurate; however, no responsibility is assumed for possible inaccuracies or omissions.
Specifications are subject to change without notice.
EMS®, Escort Memory Systems® and the EMS® logo are registered trademarks of Escort
Memory Systems, a Datalogic Group Company. Other brand and product names mentioned are
trademarks or registered trademarks of their respective holders.
Escort Memory Systems
A Datalogic Group Company
170 Technology Circle
Scotts Valley, CA 95066
Telephone (831) 438-7000
FAX (831) 438-5768
www.ems-rfid.com
email: info@ems-rfid.com
ii
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
TABLE OF CONTENTS
GETTING STARTED
1.1
1.2
3.5
3.6
3.7
3.8
3.9
Dimensions . . . . . . . . . . . . . . . . . . . . 4
RF Range and Orientation . . . . . . . . . . . . . . 7
Mounting Guidelines. . . . . . . . . . . . . . . . 12
Guidelines . . . . . . . . . . . . . . . . . . . . 13
14
Connector Panel . . . . . . . . . . . . . . . . . 14
Power Connector . . . . . . . . . . . . . . . . . 15
COM1/COM2 Connector . . . . . . . . . . . . . 15
MUX32 Connector . . . . . . . . . . . . . . . . 16
Serial Communications Cabling . . . . . . . . . . . 16
Input Connector . . . . . . . . . . . . . . . . . . 17
Output Connector . . . . . . . . . . . . . . . . . 17
Digital I/O Wiring. . . . . . . . . . . . . . . . . 18
Power Requirement . . . . . . . . . . . . . . . . 23
Power Options . . . . . . . . . . . . . . . . . . 23
Power from the MUX32 Bus . . . . . . . . . . . . 24
Power via the external supply connector . . . . . . . 24
Power from the MUX32 bus and from an external power
supply . . . . . . . . . . . . . . . . . . . . . . 26
LED Indicators . . . . . . . . . . . . . . . . . . 27
SERIAL AND BUS COMMUNICATIONS
4.1
4.2
POWER AND ELECTRICAL INTERFACE
3.1
3.2
3.3
3.4
Introduction . . . . . . . . . . . . . . . . . . . . 1
Unpacking and Inspection . . . . . . . . . . . . . . 3
MECHANICAL SPECIFICATIONS
2.1
2.2
2.3
Serial Interfaces . . . . . . . . . .
Digital Board DIP Switch . . . . .
Bus Interfaces. . . . . . . . . . .
MUX32 Interface Board DIP Switch
MENU CONFIGURATION
5.1
5.2
29
29
30
32
33
34
How to Enter Menu Configuration . . . . . . . . . 34
Set-up Operating Parameters . . . . . . . . . . . . 35
Set COM1 Parameters . . . . . . . . . . . . . . . 36
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
iii
5.3
5.4
5.5
RFID INTERFACE
6.1
6.2
6.3
6.4
iv
Set COM2 Parameters . . .
Set Operating Mode . . . .
Set RF Communication . .
Restore Factory Defaults . .
Return to Main Menu . . .
Download New Program . .
Downloading DSP Firmware
Exit to Operating Mode . .
36
36
38
38
39
39
39
40
41
Introduction . . . . . . . . . . . . . . . . .
Command Timeout . . . . . . . . . . . . . .
MUX32 and Anticollision Limitations . . . . . .
ABx Error Codes . . . . . . . . . . . . . . .
Non-Anticollision Error Codes . . . . . . . . . .
ABx Standard. . . . . . . . . . . . . . . . .
ABx Fast . . . . . . . . . . . . . . . . . . .
Anticollision Status Byte . . . . . . . . . . . .
Anticollision Commands . . . . . . . . . . . .
Family Interrogation . . . . . . . . . . . . . .
Family ID . . . . . . . . . . . . . . . . . .
Anticollision Index . . . . . . . . . . . . . .
ABx Standard Protocol . . . . . . . . . . . .
ABxS Command 4 (04H): Fill Tag . . . . . . .
ABxS Command 5 (05H): Block Read . . . . . .
ABxS Command 6 (06H): Block Write. . . . . .
ABxS Command 7 (07H): Read Tag Serial Number
ABxS Command 8 (08H): Tag Search . . . . . .
ABxS Command D (0DH): Continuous Block Read
ABxS Command 10 (10H): Set Output . . . . . .
ABxS Command 11 (11H): Input Status . . . . .
ABxS Command 84 (84H): Fill Tag All . . . . .
ABxS Command 85 (85H): Block Read All. . . .
ABxS Command 86 (86H): Block Write All . . .
ABxS Command 87 (87H): Read Tag SN All . . .
ABxS Command 88 (88H): Tag Search All . . . .
ABxS Command 89 (89H): EAS Set/Reset All . .
ABxS Command 8A (8AH): EAS Start/Stop . . .
ABxS Command 8D (8DH): Continuous Read All.
ABxS Command 8E (8EH): Memory Lock All . .
41
41
43
44
44
44
45
46
47
47
47
48
49
49
51
53
55
56
57
60
62
64
66
68
70
72
73
75
77
79
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
6.5
6.6
ABxS Command 94 (94H): SN Fill . . . . . . . . . 81
ABxS Command 95 (95H): SN Block Read. . . . . . 83
ABxS Command 96 (96H): SN Block Write . . . . . 85
ABxS Command 97 (97H): SN Block Read All . . . . 87
ABx Fast Protocol. . . . . . . . . . . . . . . . . 89
ABx Command Packet Structure: . . . . . . . . . . 89
Command/Response Size. . . . . . . . . . . . . . 90
Checksum . . . . . . . . . . . . . . . . . . . . 91
ABxF Command 4 (04H): Fill Tag . . . . . . . . . 92
ABxF Command 5 (05H): Block Read . . . . . . . . 94
ABxF Command 6 (06H): Block Write . . . . . . . 96
ABxF Command 7 (07H): Read Tag Serial Number . . 98
ABxF Command 8 (08H): Tag Search . . . . . . . 100
ABxF Command D (0DH): Continuous Block Read . 101
ABxF Command 10 (10H): Set Output . . . . . . . 104
ABxF Command 11 (11H): Input Status. . . . . . . 106
ABxF Command 84 (84H): Fill All. . . . . . . . . 108
ABxF Command 85 (85H): Block Read All . . . . . 110
ABxF Command 86 (86H): Block Write All . . . . . 112
ABxF Command 87 (87H): Read Tag SN All . . . . 114
ABxF Command 88 (88H): Tag Search All . . . . . 116
ABxF Command 89 (89H): EAS Set/Reset All. . . . 118
ABxF Command 8A (8AH): EAS Start/Stop. . . . . 120
ABxF Command 8D (8DH): Continuous Read All . . 123
ABxF Command 8E (8EH): Memory Lock All . . . 126
ABxF Command 94 (94H): SN Fill. . . . . . . . . 128
ABxF Command 95 (95H): SN Block Read . . . . . 130
ABxF Command 96 (96H): SN Block Write . . . . 132
ABxF Command 97 (97H): SN Block Read All . . . 134
ABx ASCII Protocol . . . . . . . . . . . . . . . 138
Command Packet Structure: . . . . . . . . . . . . 138
Command/Response Size . . . . . . . . . . . . . 139
Checksum . . . . . . . . . . . . . . . . . . . . 140
Example ASCII Command . . . . . . . . . . . . 140
APPENDIX: SPECIFICATIONS
142
APPENDIX: MODELS
143
APPENDIX: ASCII CHART
144
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
NOTICE
This equipment has been tested and found to comply with the limits for a
Class B digital device, pursuant to Part 15 of the FCC Rules. These limits
are designed to provide reasonable protection against harmful interference in
a residential installation. This equipment generates, uses and can radiate
radio frequency energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular
installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try and correct the interference by one or
more of the following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and the receiver.
Connect the equipment into an outlet on a circuit different
from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for
help.
CAUTION
Changes or modifications not expressly approved by Escort Memory Systems could void the user’s authority to operate the equipment.
vi
Copyright © 2000 Escort Memory Systems
LRP-Series Long-Range Passive Reader/Writer
1 GETTING STARTED
1.1 Introduction
Escort Memory Systems' passive read/write system is a complete family
of field-proven read/write Radio-Frequency Identification products. The
system consists of RFID tags, reader/writers, antennas, controllers, bus interfaces, and ancillary equipment. Tags can be attached to a product or its carrier and act as an electronic identifier, job sheet, portable database, or
manifest. Tags are read and updated via an Escort Memory Systems
Reader/Writer, through any nonconductive material, while moving or standing still.
Escort Memory Systems' LRP-Series long range passive RFID system is the
latest in our line of high performance, industrial RFID equipment. The passive design of the LRP read/write system uses the RF field from the antenna
to power the tag, eliminating the need for tag batteries. The LRP passive
read/write system is designed to provide cost effective RFID data collection
and control solutions to automation and material handling applications.
The LRP system uses the internationally recognized ISM frequency of 13.56
MHZ to both power the tag, and to establish a radio link to transfer the information.
The LRP820 is specifically designed to work with LRP-Series passive tags,
which provide 48 bytes of reprogrammable memory.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The LRP820 supports the multidrop protocol MUX32. The LRP820 is
encased in a NEMA4 enclosure and features two serial ports, 4 optoisolated inputs, 4 opto-isolated outputs. The LRP820-04 is equipped with
an antenna designed for conveyor mounting and the LRP820-08 features a
rectangular plate antenna.
The COM1 serial port is used to receive commands from the host and to
send the data back. The LRP820 COM1 can be configured either as
MUX32, RS232, or RS422 interface.
COM2 is an RS232 serial port used to download new software releases and
to setup the configuration parameters.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
1.2 Unpacking and Inspection
Unpack the LRP820 and documentation and retain the original shipping
carton and packing material in case any items need to be returned. Inspect
each item carefully for evidence of damage. If any item appears to be damaged, notify your distributor immediately. The LRP820 is delivered with the
following components:
LRP820 (-04, -08) Reader/Writer
LRP820 to Antenna cable
LRP820 Operator's Manual
The following components are required for configuring a complete system:
LRP-Series Passive Read/Write Tags
User supplied LRP820-to-host cable
MUX32 host
18 - 30 Vdc, 36 W (1.5 A @ 24 Vdc) power supply
Mating connectors. See Appendix B for more information
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
2 MECHANICAL SPECIFICATIONS
2.1 Dimensions
Figure 1 gives the dimensions for the LRP820. Figures 2-3 show the dimensions of the 04 and 08 remote antennas.
inches
mm
Figure 1 — LRP820 Dimensions
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
inches
mm
Figure 2 — LRP-04 Conveyor-Mount Antenna
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
inches
mm
Figure 3 — LRP-08 Antenna Dimensions
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
2.2 RF Range and Orientation
Figure 4 shows the correct tag orientation as it passes the antenna. Tables 1
and 2 give the typical ranges of the LRP series tags. Tables 1- 3 give the typical and guaranteed ranges of the LRP series tags.
Figure 4 — LRP-08 to Tag Orientation
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Table 1 — Antenna to Tag Ranges, LRP-04 Antenna with Metal*
Tag
Typical Range (Z)
inches/mm
Guaranteed Range
inches/mm
LRP125(HT)
2.50/64
2.00/51
LRP250(HT)
6.75/171
6.00/152
LRP250HT-FLX
6.75/171
6.00/152
LRP-L5555
6.75/171
6.00/152
LRP-L2666
5.75/146
5.00/127
LRP-L4982
8.00/203
7.00/178
LRP-L90140
9.00/229
8.00/203
LRP-P125
2.50/64
2.00/51
LRP-P3858
6.00/152
5.00/127
LRP-P5050
7.00/178
6.00/152
*These ranges are determined with metal near the -04 antenna as it would be in most conveyor
mountings. The actual tuning and testing of the -04 antenna is done with the antenna mounted between two metal rollers on metal rails. The metal rollers are mounted 1/4” from the antenna.
NOTE: Proximity to metal, CRT devices and other sources of electromagnetic radiation may affect
antenna range.
Figure 5 — Side View of RF Field, LRP-04 Antenna, Metal
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Figure 6 — End View of RF Field, LRP-04 Antenna, Metal
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Table 2 — Antenna to Tag Ranges, LRP-04 Antenna, No Metal*
Tag
Typical Range (Z)
inches/mm
Guaranteed Range
inches/mm
LRP125(HT)
3.00/76
2.25/57
LRP250(HT)
8.50/216
7.50/191
LRP250HT-FLX
8.50/216
7.50/191
LRP-L5555
8.50/216
7.50/191
LRP-L2666
7.00/128
6.00/152
LRP-L4982
10.00/254
9.00/229
LRP-L90140
12.00/305
11.00/279
LRP-P125
3.00/76
2.25/57
LRP-P3858
7.50/190
6.50/165
LRP-P5050
8.50/216
7.50/191
*These ranges calculated with no metal near the antenna.
NOTE: Proximity to metal, CRT devices and other sources of electromagnetic radiation may affect
antenna range.
Figure 7 — End View of RF Field, LRP-08 Antenna, No Metal
10
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Figure 8 — Side View of RF Field, LRP-08 Antenna, No Metal
Table 3 — Antenna to Tag Ranges, LRP-08 Antenna, No Metal
Tag
Typical Range (Z)
inches/mm
Guaranteed Range
inches/mm
LRP125(HT)
8.00/203
7.00/178
LRP250(HT)
17.00/432
15.00/381
LRP250HT-FLX
17.00/432
15.00/381
LRP-L5555
17.00/432
15.00/381
LRP-L2666
16.00/406
13.00/330
LRP-L4982
20.00/508
18.00/457
LRP-L90140
25.00/635
22.00/559
LRP-P125
8.00/203
7.00/178
LRP-P3858
16.00/406
14.00/355
LRP-P5050
17.00/432
15.00/381
*These ranges calculated with no metal near the antenna.
NOTE: Proximity to metal, CRT devices and other sources of electromagnetic radiation may affect
antenna range.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
11
2.3 Mounting Guidelines
Electromagnetic radiation and metal affect the range of the LRP820. Mount
the LRP820 and antenna to minimize the impact of these factors. The RF
field of the antenna can also cause errors when antennas are spaced too
closely together. Do not position adjacent antennas closer than 2 meters from
each other. The mounting holes are accessed through the inside of the
LRP820 Reader/Writer. Refer to Figure 9 for locations and dimensions.
The remote antennas for the LRP820 have a cable length 2 meters. Surrounding the antenna with metal will greatly reduce the reading range of the
antenna. As rule of thumb, keep any metal structure away from the antenna
at least more than the reading range along the axis, and a third of such distance on the side.
inches
mm
Figure 9 — LRP820 Mounting Holes
12
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Special mounting instructions must be followed to get optimal read/write
performance from the LRP820-08 antenna. Mount the antenna with a minimum 5.90" (150mm) spacing from any metal to the back or sides of the antenna, as shown in Figure 10.
inches
mm
Figure 10 — Antenna Mounting, -08
Guidelines
Isolate the LRP820 and antenna from electromagnetic
radiation.
Avoid surrounding LRP820 and remote antenna with metal.
Maintain at least 2 meters minimum spacing between adjacent
LRP820s or antennas.
Stay within the guaranteed range for the tag to be used.
Conform with EIA RS232, RS422 and RS485 standards.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
13
3 POWER AND ELECTRICAL INTERFACE
3.1 Connector Panel
Figure 11 shows the LRP connectors, LEDs and connector panel. Unused
connectors can be sealed with optional connector caps. Please see Appendix
B for ordering information.
Figure 11 — Connector Panel
14
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
3.2 Power Connector
Figure 12 shows the power connector pin designations.
Figure 12 — Power Connector
3.3 COM1/COM2 Connector
Figure 13 shows the connector pin designations for the COM port connections.
Figure 13 — COM1/COM2 Connector
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
15
3.4 MUX32 Connector
Figure 14 shows the connections for the MUX32/RS485 connector.
Figure 14 — MUX32 Connector Pinouts
Serial Communications Cabling
Escort Memory Systems recommends that you use Belden cables 3082A
(trunkline) and 3084A (dropline) for RS485/RS422 communications. Use
Belden cable 9941 for RS232 communications. More information on Belden
cables can be found on their web site at www.belden.com.
16
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
3.5 Input Connector
Figure 15 shows the Input Connector pin designations.
Figure 15 — Input Connector Pinouts
3.6 Output Connector
Figure 16 shows the Output Connector pin designations.
Figure 16 — Output Connector Pinouts
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
17
3.7 Digital I/O Wiring
Both the Digital Inputs and Digital Outputs are optically isolated circuits
with no common path between any channel terminal and another channel, or
between any channel and the LRP820 power. Because they are independent
and floating, the external wiring controls their use. The inputs can be configured for sensors with a PNP or NPN output. The outputs can be configured
in a Sourcing or Sinking configuration. The examples in Figures 17 through
24 show different connections for common input and output devices.
Inputs
The +IN terminal must be at a higher positive potential than the -IN terminal
for current to be sensed correctly. The voltage range is 4.5 to 30V between
the +IN and the -IN inputs and the maximum current is 25 mA.
Outputs
The output is limited to 30Vdc when off and 500 mA. These are maximum
ratings. A device that operates at 200 mA may destroy the output due to inrush current if that current exceeds 500 mA (e.g. an incandescent light). The
inductive "kick" (back EMF from a collapsing magnetic field) when a relay
is released can impose a voltage higher than 30V and destroy the output
transistor (use a backwards diode to clamp the back EMF).
18
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Figure 17 — Input from Sourcing Contact
Figure 17 shows the switch on the high side with the low side grounded. As
this is a "Dry" contact (the current is limited to 15 mA) a high quality sealed
switch should be used.
Figure 18 — Input from Sinking Contact
Figure 18 shows a switch connected on the low side with the high side connected to the positive supply. This also requires a high quality sealed contact.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
19
Figure 19 — Input from NPN Sensor
Figure 19 shows an Open Collector NPN output from a photosensor switching to ground. It can be wired as a sinking or low-side contact.
Figure 20 — Input from PNP Sensor
Figure 20 shows an Open Collector PNP output from a photosensor
switches to the positive supply. It can be wired as a sourcing or high-side
contact.
20
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Figure 21 — Sourcing Output "Contact"
Figure 21 shows a relay connected as a current sourcing "Contact." The relay is grounded and the +OUT terminal goes to the positive supply. The diode across the relay coil is essential to protect the output circuit and reduce
noise along the wiring. It should be connected at the relay to minimize the
length of wiring that could radiate noise. A 1N4001 or similar diode may be
used.
Figure 22 — Sinking Output "Contact"
Figure 22 shows a "Contact" sinking current from a relay, the -OUT terminal
is grounded and the relay goes to the positive supply. This configuration
must also have a diode across the relay coil to protect the circuit and reduce
noise.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
21
Figure 23 — Sinking Output LED Driver
In Figure 23, the LED and current limiting resistor are in series between the
positive supply and the +OUT terminal. The -OUT terminal is grounded.
The resistor in series with the LED sets the forward current. 1.2K will provide 20 mA LED current when run from 24 Vdc.
Figure 24 — Output to TTL or CMOS
In Figure 24 the output acts as an Open Collector. This will provide a TTL
or CMOS compatible signal when a 1K to 10K pull-up to +5 Vdc (the logic
supply) is used.
22
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
3.8 Power Requirement
The LRP820 power supply requirements are:
18 to 30Vdc
31Watts maximum consumption
The maximum current consumption at 24Vdc is 1.3 A.
Power Options
There are three options for powering the LRP820:
Powered from the MUX32 bus (default)
This is the default configuration for powering the LRP820. If the
power available over your MUX32 network is not sufficient to
power the LRP820, use one of the following methods.
Powered via the external power connector
This is how you must power the LRP820 if you are not connecting
the LRP820 to a MUX32 network.
Powered from an external power supply and isolated MUX32
bus power (isolated mode)
When the LRP is powered from both sources, the LRP820 will be
opto-isolated from the MUX32 bus.
The MUX32 interface board will draw 2.5 mA at 24 Vdc from the
MUX32 bus when the LRP820 is powered with this method.
Power to the external power connector should conform to the specifications given above.
If you choose to power the LRP820 with an external supply via the power
connector, you must open the LRP820 and changed jumper and cable locations. The following sections describe how to make these changes.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
23
Power from the MUX32 Bus
By default, the LRP820 is configured to run with power supplied by the network. In this mode, there is no galvanic isolation between the MUX32
wires and the LRP820, and there is no need for a separate power supply.
If you choose to power the LRP820 form the MUX32 bus, you do not need
to make any internal changes to cables and jumpers. Wire power according
to the pinouts given for the MUX32 connector in Figure 14, page 16.
Power via the external supply connector
The LRP820 contains components sensitive to electro-static discharge. Take
proper grounding precautions before opening the LRP820.
To change the LRP820 to run in isolated mode:
1. Open the LPR820 by loosening the four captive screws that secure the cover.
2. Refer to Figure 25 and then move the power cable, labeled assembly 10-3110, from connector J7 to J9.
3. The MUX32 cable, labeled assembly 10-3111, must then exchange places with the power cable, moving from J9 to J7.
Figure 25 — Power Cable Connectors J7 and J9
24
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
4. Referring to Figure 26, locate jumper J1 and move the shunt from
pins 4 and 3 to pins 2 and 1.
5. Close the LRP820 and connect a separate +24V power supply to
the external power connector shown in Figure 12, page 15.
Figure 26 — Power Jumper Position for External Powering Only
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
25
Power from the MUX32 bus and from an external power supply
When the LRP is powered from both sources, the LRP820 will be
opto-isolated from the MUX32 bus.
The LRP820 contains components sensitive to electro-static discharge. Take
proper grounding precautions before opening the LRP820.
To power the LRP820 from an external supply and the MUX32 bus:
1. Open the LPR820 by loosening the four captive screws that secure the cover.
2. Refer to Figure 25 and then move the power cable, labeled assembly 10-3110, from connector J7 to J9.
3. The MUX32 cable, labeled assembly 10-3111, must then exchange places with the power cable, moving from J9 to J7.
4. Make sure that the jumper on J1of the MUX32 Interface Board
connects pins 3 and 4, and then close the LRP820.
5. Connect a separate +24V power supply to the external power
connector shown in Figure 12, page 15.
6. Wire the MUX32 interface and power according to the pinouts
given for the MUX32 connector in Figure 14, page 16.
26
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
3.9 LED Indicators
The LRP820 has 16 LEDs indicating status of the LRP820 Reader/Writer,
interface communications, and I/O status.
Figure 27 — LRP820 Front with LEDs
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
27
Table 4 shows these LEDs and their meaning.
Table 4 — LED Indicators
LED
Color
Indicates
PWR
red
The LRP820 is receiving power
RF
green
RF Data Transfer
ANT
red
Antenna On and tag in field
ERROR
Red
Unsuccessful RF command (.5 sec. flash)
Entering Download Mode via DIP switch 5 (4 flashes)
CONFIG
green
Successful RF command - 1 .5 sec. flash
ERROR + green/red
CONFIG
Entering Operating Mode - 4 alternate flashes
Configuration Mode initiated (CTRL-D) - Both LEDS flash 4 times
Configuration Mode initiated (CTRL-E) - Both LEDS flash 2 times
IN-A
yellow
Input active
IN-B
yellow
Input active
IN-C
yellow
Input active
IN-D
yellow
Input active
COM1
green/red
Incoming data (RX): red
Outgoing data (TX): green
COM2
green/red
Incoming data (RX): red
Outgoing data (TX): green
MUX32
red
Data transfer (RX/TX): red
OUT-A
green
Output active
OUT-B
green
Output active
OUT-C
green
Output active
OUT-D
green
Output active
Additional LED behavior may be observed during certain commands and
conditions. This behavior will be indicated as appropriate elsewhere in this
manual.
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Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
4 SERIAL AND BUS COMMUNICATIONS
4.1 Serial Interfaces
The LRP820 has RS232 and RS422 available on the COM1 serial port.
COM2 is configured for RS232 communications and is reserved for downloading programs to the LRP820 and for setting up the configuration
parameters.
Both RS232 and RS422 interfaces are opto-isolated. The RS422 interface
is specially suitable for long cable, noisy environment links.
The specification for the COM1 interface follows:
Baud rate: 1200, 2400, 4800, 9600, 19200, 38400 bps
Data: 7, 8
Parity: Even, Odd, None
Handshake: None, Xon/Xoff
The specification for the COM2 interface follows:
Baud rate: 1200, 2400, 4800, 9600, 19200 bps
Data: 7, 8
Parity: Even, Odd, None
Handshake: None, Xon/Xoff
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
29
Digital Board DIP Switch
The digital board is mounted inside the top of the LRP820 enclosure. The
first 5 switches of the main board sets the COM1 baud rate, electrical
interface, and the download options for COM2. Switches 6, 7 and 8 are not
used and should remain OFF. When switch 1 and 2 are both set ON, the
baud rate is set via the Configuration Menu.
Figure 28 — Digital Board with DIP Switch
NOTE:
When you set switch 5 ON to enable download, the default parameters will
first be restored and saved to the non-volatile memory.
The baud rate configuration on the main board only applies to the RS232
and RS422 serial interfaces. When a Bus Interface (MUX32) is selected, the
baud rate is set by the Interface Board DIP switches.
30
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
NOTE:
DIP switch 4 must be in the default ON position for the MUX32 interface to
function.
Table 5 Main Board DIP Switch Settings
Baud rate
Download/
Restore
Defaults
Interface
SW 2
SW 3
SW 4
SW 5
Settings
9600
ON
ON
19200
ON
38400
ON
Set from Configuration Menu
RS232
ON
ON
RS422
ON
MUX32
ON
Reserved
Disabled
ON
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Enabled Download/ Restore defaults
31
4.2 Bus Interfaces
The COM1 serial port, beside the RS232 or RS422 options, can be configured as a MUX32 interface.
The following MUX32 bus parameters are set by the DIP switches found on
the Interface Board.
Bus Rate: 9600, 346Kbps
MUX32 Slave Address
Figure 29 — MUX32 Interface Board DIP Switch
32
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
MUX32 Interface Board DIP Switch
S1 is an eight position DIP switch. Switches 1 to 6 set the MUX32 slave
address, switches 6 and 7 are reserved and switch 8 sets the bus rate. Table 6
shows these settings.
Table 6 — MUX32 DIP Switch Settings
MUX32 Address
SW 1 SW 2 SW 3
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
Reserved
Bus Rate
SW 4 SW 5 SW 6 SW 7 SW 8
Switches 6 and
7 are not used
- leave in the
OFF
position
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
ON
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Setting
MUX Addr. 0
MUX Addr. 1
MUX Addr. 2
MUX Addr. 3
MUX Addr. 4
MUX Addr. 5
MUX Addr. 6
MUX Addr. 7
MUX Addr. 8
MUX Addr. 9
MUX Addr. 10
MUX Addr. 11
MUX Addr. 12
MUX Addr. 13
MUX Addr. 14
MUX Addr. 15
MUX Addr. 16
MUX Addr. 17
MUX Addr. 18
MUX Addr. 19
MUX Addr. 20
MUX Addr. 21
MUX Addr. 22
MUX Addr. 23
MUX Addr. 24
MUX Addr. 25
MUX Addr. 26
MUX Addr. 27
MUX Addr. 28
MUX Addr. 29
MUX Addr. 30
MUX Addr. 31
9600 bps
346K bps
33
5 MENU CONFIGURATION
The LRP820 feature a menu-driven program designed to give convenient
access to the serial parameters, restore defaults or change operating modes.
5.1 How to Enter Menu Configuration
Begin by connecting the COM2 port to your PC host (see table below) and
running EC that is available on the diskette or from Escort Memory Systems’ Web site at www.ems-rfid.com.
LRP820
Standard PC Serial Port
COM2 Pin Number
Signal Name
DB9 Pin Number
Signal Name
TX
RX
RX
TX
GND
GND
Set the serial parameters to the LRP820 default settings or the last known
state of COM2.
The default settings for COM2 are as follows:
Baud
9600
Parity
None
Data bits
Stop bits
Flow control
None
If you can not establish communications with COM2, do the following to
restore the default values.
1. Place DIP switch five in the ON position and cycle power to the
LRP820 or press the reset switch. This will load the default values.
2. Place DIP switch 5 in the OFF position and cycle power once
more.
Please refer to Chapter 4, Serial and Bus Communications for more information on the serial interface.
34
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
To enter the Main Board configuration menu, cycle power or press the reset
switch, and then press CTRL-D within the first seven seconds of the initialization. The LRP820 will enter the Configuration Menu. As the LRP820
starts the Configuration program, both the RF and CONFIG LEDs will
flash. The Main Board Configuration menu will display with the current
main board software version number together with the DSP firmware version.
******************************************************
LRP820 Standard Program
Software V1.7C, June 2000
DSP Firmware V1.7B, June 2000
*******************************************************
[1] Set-up Operating Parameters
[2] Download New Program
[3] Download DSP Firmware
[4] Exit to Operating Mode
Enter Selection:
5.2 Set-up Operating Parameters
To change the operating parameters of the LRP820, enter 1 at the initial
menu. The following menu will be displayed, listing the current settings:
The exact appearance of the menu display will depend on the settings you
have made, and will be updated when you save your changes.
Serial Port COM1: RS232, 9600, N, 8, 1, No handshake (DIP switches)
Serial Port COM2: RS232, 9600, N, 8, 1, No handshake
Operating Mode: ABx Standard
RF Communication: Fast Mode
[1] Set COM1 Parameters
[2] Set COM2 Parameters
[3] Set Operating Mode
[4] Set RF Communications
[5] Restore Factory Defaults
[6] Return to Main Menu
Enter Selection:
Enter the number of the sub-menu you wish to enter. When you have made
your selection you will be prompted to save your changes to the non-volatile
EEPROM. For the new settings to take effect, you must save your changes
to the EEPROM and reset the LRP820. If you do not save changes to the
EEPROM, the new settings will be effective only until the LRP820 is reset.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
35
The following sub-menus are presented here in their entirety. Actually the
menus will presented one option at time, advancing as you enter selections.
Some options shown are dependent on earlier selections.
Set COM1 Parameters
Selecting 1 from the above menu will present the following display for the
COM1 parameters. These settings are valid only if you are not using the
DeviceNet Interfaces (e.g. DIP switch 4 is in the OFF position). Enter the
appropriate number at each prompt. The default values are indicated by an
asterisk (*).
*** Set COM1 Parameters ***
Baud Rate? [0] 1200 [1] 2400 [2] 4800 [3] 9600* [4] 19200 [5] 38400
Data size? [0] 7 bit [1] 8 bit*
Parity? [0] None* [1] Even [2] Odd
Handshake? [0] None* [1] Xon/Xoff
Save Changes to EEPROM? [0] No [1] Yes
Set COM2 Parameters
Selecting 2 from the above menu will bring to the following display for the
COM2 parameters. Enter the appropriate number at each prompt. The
default values are indicated by an asterisk.
*** Set COM2 Parameters ***
Baud Rate? [0] 1200 [1] 2400 [2] 4800 [3] 9600* [4] 19200
Data size? [0] 7 bit [1] 8 bit*
Parity? [0] None* [1] Even [2] Odd
Handshake? [0] None* [1] Xon/Xoff
Save Changes to EEPROM? [0] No [1] Yes
Set Operating Mode
The Set Operating Mode menu allows you to choose the command protocol
the LRP820 will use or configure it to automatically enter Continuous Read
Mode upon start-up.
36
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
*** Set Operating Mode ***
Command Protocol? [0] ABx Standard* [1] ABx Fast [2] ABx ASCII
Checksum? [0] Disabled* [1] Enabled
Power up in Continuous Read Mode? [0] NO [1] Single Tag [2] Multiple Tag
Start Address (0 to 47)
Length (1 to 48)
Delay Between Duplicate Decodes (0 to 60)
Raw Read Response? [0] NO [1] CR terminate [2] CR/LF terminate
Save Changes to EEPROM? [0] No [1] Yes
Command Protocol?
The LRP820 offers three modes for the transfer of data and commands. ABx
Standard (ABxS) uses only the LSB for tag data while ABx Fast (ABxF)
will use both the MSB and the LSB for the passing of data. ABx ASCII
(ABxA) mode permits RFID operations using seven bit data packets in the
form of printable ASCII characters.
Checksum?
ABx Fast and ABx ASCII also permits you to include a checksum in the
command. To use a checksum value with the ABx commands, you must
enable the checksum option. It is recommended that you enable the
checksum option.
Power up in Continuous Read Mode?
You also have the option of setting the LRP820 to start-up in Continuous
Read Mode. When you have configured the LRP820 to function in this
manner, you do not issue commands to the LRP820. It will, upon start-up,
enter directly into a Continuous Read Mode. Since this bypasses the normal
command parameters, you must specify the Continuous Read Mode parameters.
The LRP820 will respond to other commands and resume Continuous Read
Mode when completed.
If you are using your LRP820 in this mode, you must choose if you want the
LRP820 to read a single tag or read multiple tags within the field.
To exit Continuous Read Mode you must either re-enter the configuration
menu and select NO from the Power up in Continuous Read Mode option,
or issue a Continuous Read command from the host with a read length of 0
as described in Chapter 6, RFID Interface.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
37
Start Address (0-47)
Enter the tag address where you want the read to begin.
Length (1-48)
Enter the length of the read you wish the LRP820 to perform. Make certain
that the length value does not exceed the number of possible addresses following the starting tag address. Entering a read length of 0 will disable Continuous Read Mode.
Delay Between Identical Decodes (0-60)
The Delay Between Identical Decodes parameters can have a value of 0 to
60 seconds. When the Delay Between Identical Decodes is set to 0, the
LRP820 will continuously read AND transmit tag data to the host. This can
flood the buffers and cause communication errors and data loss.
Raw Read Response?
If you have selected ABx Fast or ABx ASCII, you have the option of stripping the command protocol from the data and adding a terminator to separate the data packets. You can choose a CR (0DH) or CR/LF (0DH, 0AH) to
terminate the data.
Set RF Communication
The LRP820 should be configured with the default (0) Fast Mode.
*** Set RF Communication ***
RF Communication? [0] Fast Mode* [1] Standard Mode 0
Save Changes to EEPROM? [0] No [1] Yes
Restore Factory Defaults
It is often helpful during troubleshooting to restore the LRP820 to known
default values. To do so, select 1from this menu.
*** Restore Factory Defaults ***
Restore Factory Default? [0] No [1] Yes
The restored defaults will be saved to the EEPROM. The communication
defaults can also be restored by placing the main board DIP switch number 5
in the ON position and then restarting the LRP820. After you have saved
any changes, you must re-initialize the LRP820 with switch 5 in the OFF
position.
38
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Return to Main Menu
When you have completed your configuration, entering 5 will return you to
the initial menu. Unsaved changes will be effective until the LRP820 is reset. Saved changes will be loaded automatically the next time the LRP820 is
reset.
5.3 Download New Program
Before attempting to download new firmware to the LRP820 main board,
read the instructions provided in a readme.txt file on the update diskette.
When you select 2 from the Main Menu, the LRP820 will display information on the current program and prompt you to begin the download.
*** Download New Program***
Program Size
:21824 Bytes
Program Checksum
:5AE0H (OK)
Free Program Memory
:39600 Bytes
Flash Write Counter
:2 times
Press a key to start Downloading
After you have pressed a key, the LRP820 will display:
Send the Intel Hex file. Downloading now.
Send the new program file via your terminal emulation program in ASCII
text or Hexadecimal format. Wait 10 seconds after the download is complete
before resetting the LRP820.
IMPORTANT:
It is not necessary to download firmware into the unit unless instructed to do
so by Escort Memory Systems technical support personnel.
5.4 Downloading DSP Firmware
Before attempting to download new firmware to the LRP820 main board,
read the instructions provided in a readme.txt file on the update diskette.
When upgrading software in the controller the number and meaning of the
configuration parameters may not match between the old and new software.
The old settings may not be interpreted properly with the new software. BeCopyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
39
fore downloading another version of software, display and record the current
configuration settings. Then download the new software version. Set switch
5 (on the main board) on and apply power to initialize the configuration parameters to their default states. When the LEDs stop flashing, turn Switch 5
to Off and press the reset switch. Enter the Configuration Menu and re-enter
any non-default configuration parameters.
When you select 3 from the Main Menu, the LRP820 will prompt you to
begin the download.
*** Download DSP Firmware***
Press a key to start Downloading
After you have pressed a key, the LRP820 will display:
Send the Intel Hex file. Downloading now.
Send the new firmware via your terminal emulation program in ASCII text
or Hexadecimal format. The firmware will be automatically transferred to
the DSP Flash Memory. Wait 10 seconds after the download is complete
before resetting the LRP820.
Record: 750
Download OK
File Transfer to DSP
Blocco 24/24
DSP Flash Programming...
New Firmware Transferred to DSP
WARNING:
Do not download INTERFACE BOARD firmware to the main board.
IMPORTANT:
It is not necessary to download firmware into the unit unless instructed to do
so by Escort Memory Systems technical support personnel.
5.5 Exit to Operating Mode
This option is available if you wish to use temporary, unsaved, configuration
parameters. The unsaved options you have selected will be used until the
LRP820 is reset and the saved parameters are restored.
40
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
6 RFID INTERFACE
6.1 Introduction
The LRP820 offer three possible command protocols: ABx Standard, ABx
Fast and ABx ASCII. The ABx Standard format is word-based and is compatible with most existing RFID systems by Escort Memory Systems. The
ABx Fast protocol is a byte-based packet structure that permits command
execution with fewer total bytes transferred. The ABx ASCII protocol is also
a byte-based format that permits the execution of RFID commands using a
seven-bit ASCII character set.
The ABx Fast protocol is the most efficient and therefore recommended by
Escort Memory Systems. Table 7 on page 39 lists the ABx commands available for the LRP820.
The LRP820 command set is made of two subsets: the ‘Non-Anticollision’
commands and the ‘Anticollision’ commands. The Anticollision commands
allow you to manage the multiple-tags-in-field capability of the LRP system.
Command Timeout
Most commands have a timeout value that is used to limit the time the
LRP820 will attempt to complete the specified operation. This value is given
in 1 ms increments with a maximum value of 65,534 ms (FFFEH). A timeout value of 0 will generate a syntax error.
Between 500ms and 1000ms is recommended for a timeout value for single
tag commands. Shorter timeouts may result in diminished range. A 30ms
timeout value is the shortest allowable timeout and should only be used for
short range, single tag command applications. Multiple tag commands will
require longer timeout values. For time critical applications the timeout
value should be tested to obtain the maximum performance value. A longer
timeout value does not mean that the command will take any longer to execute if the tag being addressed is in the field, it only represents the period of
time (in milliseconds) the unit will attempt to execute the command. If the
tag is present, the response time to execute the command will be the same
whether the timeout is 100ms or 10,000ms.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
41
Table 7 - ABx Command Set Listing
Non-Anticollision Commands
04 Hex
Fill Tag
05 Hex
Block Read
06 Hex
Block Write
07 Hex
Read Tag Serial Number
08 Hex
Tag Search
0D Hex
Continuous Block Read
10 Hex
Set Output
11 Hex
Input Status
Anticollision Commands
84 Hex
Fill Tag All*
85 Hex
Block Read All*
86 Hex
Block Write All*
87 Hex
Read Tag SN All*
88 Hex
Tag Search All*
89 Hex
EAS Set/Reset
8A Hex
EAS Start/Stop
8D Hex
Continuous Read All*
8E Hex
Memory Lock All*
94 Hex
SN Fill
95 Hex
SN Block Read
96 Hex
SN Block Write
97 Hex
SN Block Read All*
*These commands can not be used with a MUX32 interface.
NOTE:
The delay between the characters of the command packet the LRP820 cannot be longer than 200 ms.
42
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
MUX32 and Anticollision Limitations
MUX32 does not support the following “All” commands in multiple
tag-in-field mode (i.e. Anticollision Index is not 0):
Command Number
Command
84H
Fill Tag All
85H
Block Read All
86H
Block Write All
87H
Read Tag SN All
88H
Tag Search All
8DH
Continuous Read All
97H
SN Block Read All
The entire command set is available for point-to-point serial communications.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
43
6.2 ABx Error Codes
Non-Anticollision Error Codes
The LRP820 will return an error if it encounters a fault during operation.
Table 8 lists the possible error codes in Hexadecimal format.
Table 8 — Non-Anticollision Error Codes
Error Code
04H
05H
06H
08H
21H
Description
Fill Operation has failed
Block Read has failed
Block Write has failed
Search Tag Operation failed
Input Command does not match pre-defined format (syntax error)
Additionally there are internal DSP errors, F1H through F5H, for use by
Escort Memory Systems technical support.
ABx Standard
ABxS error codes are returned in the LSB of the second register passed to
the PLC. The format of the error response is shown below.
MSB
LSB
Remarks
AAH
FFH
Command Error
00H
XXH
Error Code
FFH
FFH
Message Terminator
A Block Write fail error message would appear as: AAFF 0006 FFFFH.
44
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABx Fast
The format of the error response is shown below.
Field
Bytes Contents
Header

02H
Response Size
00H
02H
02H
Error Flag
FFH
Error Code
XXH
Checksum
XXH
Terminators 
03H
A Block Write fail error message would appear as: 0202 0002 FF06 F803H.
ABx ASCII
The format of the error response is shown below.
Field
# of ASCII
characters
Contents
Header

 02H
Response Size
Packet length in bytes excluding the header, response size,
checksum and terminator bytes
Error Flag
FFH
Error Code
XXH - see Table 7 for details
 02H
Checksum
XXH - optional checksum
Terminators 
 03H
In ABx ASCII format the response size is the number of hex values and not
the number of ASCII characters used to represent the hex value.
A Block Write fail error message would appear as an ASCII character
string: 0002FF06F8.
In hexadecimal the commands appears as:
02H 02H 30H 30H 30H 32H 46H 46H 30H 36H 46H 38H 03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
45
Anticollision Status Byte
When the anticollision commands encounter a fault condition they indicate
the error in a STATUS byte returned in the response. If any of the flag bits of
the Status byte are set, then an error has occurred during command execution. The format of the response is in all other ways, the same as a successful
response.
The STATUS byte is defined as follows:
Antenna
Failure
R/W Error Collisions
Internal
Error
Timeout
Verify
Error
Reserved Reserved
Some of the error conditions are the same as found in the non-anticollision
commands, some are new and relate only to the anticollision.
If any of the flag bits of the returned Status are set, then that condition occurred during the command execution. Multiple conditions can occur in the
same command.
Antenna
Failure
R/W error
Collision
Internal Error
Timeout
Verify Error
There is an error at the antenna
Error during the tag memory access
Collisions detected: more than one tag in the field answered
to the LRP820 at the same time, meaning a higher
Anticollision Index probably needs to be set
Internal error in low-level firmware
(contact Escort Memory Systems technical assistance)
Timeout expired
Set when re-read verification fails
Syntax Errors
Syntax errors (error code 21H) will be returned in the same format as
described for the non-anticollision commands.
46
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
6.3 Anticollision Commands
Family Interrogation
The anticollision commands always have a Family ID and an Anticollision
Index as parameters. These parameters manage the read/writes when multiple tags are in the same reading field. The Family ID and Anticollision Index
can be used separately or together. If the Family ID is zero, that feature is
disabled, if the Anticollision Index is zero, the multiple tag-in-field feature
is disabled as well.
If both the features are disabled, the commands operate exactly the same as
the Non-Anticollision commands.
Family ID
The Family ID is a 1 byte field in the LRP tag memory at address 0. When
the Family ID parameter is set to 0, the command is broadcast to all the tags
in the field. On the other hand, if it is not equal to 0, only the tags with the
specified Family ID in byte 0 will respond to the LRP820.
This feature can help in implementing a multi-level organization of the tags,
by permitting the selective reading of tags by Family ID. This gives faster
access to the tags than by using Anticollision Index alone. As previously
noted, Family ID and the Anticollision Index can be used together for
increased efficiency.
When using the Family ID feature, the first byte of tag memory is reserved,
and thus only 47 bytes are allowed to be used. When the feature is disabled,
48 bytes are available for user data.
For this reason, in the read and write commands, once the parameter Family
ID is not equal to zero, the addresses can go from 1 to 47, and the size from
0 to 47. However, when the Family Code is zero, the addresses can start
from 0, and the size can be up to 48.
In order to initialize a tag with a chosen Family ID, byte 0 in the tag must be
set to that value by means of a Block Write or a Block Write All command.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
47
Anticollision Index
The Anticollision Index controls the tag reading algorithm to achieve the
fastest reading speed for the number of tags expected in the reading field at
any given moment. It can also disable the multiple tag-in-field feature.
The Anticollision Index should be set in relation to the maximum number
of tags possibly present in the reading field at one time. Setting the
Anticollision Index higher increases the number of tags that will be expected
to be read in the field. Lowering the Index speeds up the tag read operation.
Selecting the Anticollision Index is therefore a tradeoff choice between the
number of tags in the reading field, and the time required to read/write to
them. Regardless of the index setting, ALL tags present will be read. The
index simply makes the process more efficient.
None of the Anticollision Index values will absolutely limit the number of
tags that can be read by the LRP820. The following table can assist you in
setting the Index value, but tests should be done to find the best value. The
allowed values are from 0 to 7.
Anticollision Index
(*) anticollision disabled
Max number of tags
1 (*)
2-4
4-8
8-16
16-32
32-64
64-128
>128
Some commands return or have as a parameter, the Serial Number (SN).
The tag serial number is a unique read-only, 64 bit (8 bytes) code in the tag
memory. SN commands can be used to selectively write to a specific tag,
identified by the SN. Target tag can be identified with a previous SN read
command.
Note that the anticollision commands, except SN Block Write, SN Fill and
Tag Search All, will return a response packet only after the timeout is expired. If the command has the Anticollision Index set to 0, then a response
will be returned after the first successful operation.
48
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The Anticollision Commands return a successful response whenever the operation has been successfully completed on at least 1 tag. They will return
an Error Response when no tag, as permitted by the Family ID and
Anticollision Index, can be found in the antenna field.
Note also that all the start addresses, byte lengths and packet sizes are expressed in 2 byte words, in order to be compatible with the HMS commands
and to allow future developments.
6.4 ABx
ABx Standard
Standard Protocol
Protocol
6.3
The ABx standard is a binary protocol, word (2-byte) oriented, so the syntax
table reports the Most Significant Byte (MSB) and the Least Significant
Byte (LSB). In the serial transmission, the MSB is transmitted first.
ABxS Command 4 (04H): Fill Tag
DESCRIPTION
Fill an RFID tag with a one byte value over multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses.
The fill function requires one data value byte, a starting address, and a fill
length. It will then proceed to fill the tag with the data value byte, starting at
the specified start address for the specified number of consecutive bytes.
When Fill Length is set to 0, the LRP820 will write fill data from the start
address to the end of the tag's memory. The timeout value is given in 1 msec
increments and can have a value of 1EH to FFFEH (65,534 ms). When the
timeout is set to 0, the LRP820 will return a syntax error.
Field
Remarks
Command
Command number in hex preceded by AAH
Start Address
The tag address where the fill will start
Fill Length
The number of tag addresses to be filled in bytes
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Data Value Byte
The byte to be used as fill
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
49
EXAMPLE
Writes 'A' (41H) to the tag starting at address 0005H for the following next
consecutive 10 bytes. A timeout of 2 seconds (07D0H = 2000 x 1 msec
increments) is set for the completion of the configuration.
Command from Host
Response from LRP820
MSB
AAH
00H
00H
LSB
04H
05H
0AH
MSB
AAH
FFH
07H
00H
FFH
D0H
41H
FFH
50
Remarks
Perform Command 4
Start Address = 0005H
Fill Length= 10 bytes
(000AH)
Timeout value
Data Value Byte = 41H
Message Terminator
LSB
04H
FFH
Remarks
Command echo
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 5 (05H): Block Read
DESCRIPTION
Read a block of data from an RFID tag.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host with one command. The timeout value is given in 1 msec increments
and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is
set to 0, the LRP820 will return a syntax error.
The Block Read command consists of a start address and length, followed
by the message terminator, FFFFH, as shown below. If the read range exceeds the last tag address, the LRP820 will return error message 21H, invalid format.
The data read from the tag is returned in the LSB of the register, and the
MSB is always 00H.
Field
Remarks
Command
Command number in hex preceded by AAH
Start Address
The tag address where the read will start
Read Length
The number of tag addresses to be read
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
51
EXAMPLE:
Reads 8 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Read.
Command from Host
Response from LRP820
MSB
AAH
00H
00H
LSB
05H
01H
08H
MSB
LSB
AAH
05H
Command echo
00H
52H
Read Data 1 = 52H
00H
46H
Read Data 2 = 46H
07H
FFH
D0H
FFH
00H
49H
Read Data 3 = 49H
00H
44H
Read Data 4 = 44H
00H
20H
Read Data 5 = 20H
00H
54H
Read Data 6 = 54H
00H
61H
Read Data 7 = 61H
00H
67H
Read Data 8 = 67H
FFH
FFH
Message Terminator
52
Remarks
Perform Command 5
Start Address = 0001H
Read Block Length = 8 bytes
(0008H)
Timeout Value
Message Terminator
Remarks
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 6 (06H): Block Write
DESCRIPTION
Write a block of data to an RFID tag.
DISCUSSION
This command is used to write segments of data to contiguous areas of tag
memory. It is capable of transferring up to 48 bytes of data transferred from
the Host with one command. The timeout value is given in 1 msec increments and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The Block Write command consists of a start address followed by the data
stream to be written to the RFID tag. If the write range exceeds the last tag
address, the LRP820 will return error message 21H, invalid format. The
LRP820 will also return an error if the write length is 0.
The data to be written to the tag is contained in the LSB of the register, and
the MSB is always 00H.
Field
Remarks
Command
Command number in hex preceded by AAH
Start Address
The tag address where the write will start
Write Length
The number of tag addresses to be written to in bytes
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Write Data
The data to be written
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
53
EXAMPLE:
Writes 4 bytes of data to the tag starting at address 0020H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Write.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
06H
Perform Command 6
AAH
06H
Command echo
00H
20H
Start Address = 0020H
FFH
FFH
Message Terminator
00H
04H
Write Length = 4 bytes
07H
D0H
Timeout Value
00H
52H
Write Data 1 = 52H
00H
46H
Write Data 2 = 46H
00H
49H
Write Data 3 = 49H
00H
44H
Write Data 4 = 44H
FFH
FFH
Message Terminator
54
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 7 (07H): Read Tag Serial Number
DESCRIPTION
This command retrieves the eight-byte tag serial number.
DISCUSSION
Each LRP tag has an unique (264 possible numbers) serial number. This
number cannot be changed and is not part of the 48 available data bytes. The
tag serial number will be returned in the LSB only, with the MSB as 00H.
Field
Remarks
Command
Command number in hex preceded by AAH
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
EXAMPLE:
This example will wait until a tag is in range and then reads the 8-byte serial
number. In this example the ID is 1E6E3DC200000000H in hexadecimal.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
LSB
Remarks
AAH
07H
Perform Command 7
AAH
07H
Command Echo
07H
D0H
Timeout
00H
1EH
First SN byte
FFH
FFH
Message Terminator
00H
6EH
Second SN byte
00H
3DH
Third SN byte
00H
C2H
Fourth SN byte
00H
00H
Fifth SN byte
00H
00H
Sixth SN byte
00H
00H
Seventh SN byte
00H
00H
Eighth SN byte
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
55
ABxS Command 8 (08H): Tag Search
DESCRIPTION
Check to see if there is an RFID tag in the LRP820 field.
DISCUSSION
This command will activate LRP820 to "look" for a tag in the RF field. If the
LRP820 finds a tag it will return a command echo to the host. The timeout
value is given in 1 msec increments and can have a value of 1EH to FFFEH
(65,534 ms). When the timeout is set to 0, the LRP820 will return a syntax
error. If no tag is present, it will return an error message. See Section 6.2 for
more information on error codes.
Field
Remarks
Command
Command number in hex preceded by AAH
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
EXAMPLE
Checks for an RFID tag in the RF field. A timeout of 2 seconds (07D0H =
2000 x 1 msec increments) is set for the completion of the Tag Search.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
Remarks
08H
Command echo
FFH
Message Terminator
LSB
AAH
08H
Perform Command 8
AAH
07H
D0H
Timeout Value
FFH
FFH
FFH
Message Terminator
56
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command D (0DH): Continuous Block Read
DESCRIPTION
When in Continuous Block Read mode, the LRP820 sends block reads continuously to any tag in range of the antenna. When a tag enters the RF field,
it is read and the data passed to the host computer. The LRP820 continues to
read the tag but will not send the same data to the host until the tag has been
outside the RF field for a specified time period. This Delay Between Identical Decodes parameter prevents redundant data transmissions when the
LRP820 is in Continuous Block Read mode.
DISCUSSION
The initiate/cancel Continuous Block Read command contains three parameters: read length, start address, and delay between identical decodes. The
read length parameter switches the mode. Any valid, non-zero length (1-48)
will set the LRP820 into Continuous Block Read mode. A read length value
of 00H will turn Continuous Block Mode off.
The Delay Between Identical Decodes parameters can have a value of 0 to
60 seconds. When the Delay Between Identical Decodes is set to 0, the
LRP820 will continuously read AND transmit tag data to the host. This can
flood the buffers and cause communication errors and data loss.
If the LRP820 receives other commands from the host, it will execute them
and then resume Continuous Block Read mode. To exit Continuous Block
Read mode, issue the command with a read length of 0.
In Continuous Block Read mode, the LEDs will display as follows:
LED
Behavior
ANT LED
ON
Description
Assumes the Antenna is powered and functioning
CONFIG LED BLINK
Tag entered the RF field
RF LED
ON
A tag has been read and is still in the field
RF LED
OFF
A read tag has been out of range for the specified time
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
57
The command is formatted as follows.
Field
Remarks
Command
Command number in hex preceded by AAH
Start Address
2 byte value for the start address in the tag
Read Length
2 byte value for the block read length
Delay Between
Identical Decodes
Time the tag must be out of the antenna range before the LRP820 will
transmit data again from that tag. Value is expressed in 1 second units.
Message Terminator
FFFFH
EXAMPLE
This example places the LRP820 in Continuous Block Read mode and reads
8 bytes of data from the tag starting at address 0001H. A delay between
identical reads of 2 seconds (0002H = 2 x 1 second increments) is set.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
0DH
Perform Command D
AAH
0DH
Command echo
00H
01H
Start address
FFH
FFH
Message Terminator
00H
08H
Read 8 bytes
00H
02H
2 second delay
FFH
FFH
Message Terminator
The LRP820 will first return an acknowledgment of the command followed
by a response containing read data when a tag enters the antenna field.
Response from LRP820
MSB
LSB
Remarks
AAH
0DH
Command echo
00H
52H
Read data byte 1
00H
46H
Read data byte 2
00H
49H
Read data byte 3
00H
44H
Read data byte 4
00H
41H
Read data byte 5
00H
20H
Read data byte 6
00H
54H
Read data byte 7
00H
61H
Read data byte 8
FFH
FFH
Message Terminator
58
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
To exit Continuous Block Read mode, Send the command with the read
length variable set to 0 as shown below. The value of the other variables are
not considered.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
0DH
Perform Command D
AAH
0DH
Command echo
00H
01H
Start address
FFH
FFH
Message Terminator
00H
00H
Read 0 bytes/end mode
00H
02H
2 second delay
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
59
ABxS Command 10 (10H): Set Output
DESCRIPTION
Set the levels of the output lines and output LEDs "A" through "D."
DISCUSSION
This command uses bit logic to set the levels of the digital output lines. The
four least significant bit toggle the output levels; 1 = ON and 0 = OFF. The
following chart shows the hex values for all output high combinations. To
reset all output, issue the command with 00H in the second word.
MSB
LSB
Remarks
LSB Bit 3 LSB Bit 2 LSB Bit 1 LSB Bit 0
Output D Output C Output B Output A
00H
00H
Reset A, B, C, D
00H
01H
Set Output A - Reset B, C, D
00H
02H
Set Output B - Reset A, C, D
00H
03H
Set Output A, B - Reset C, D
00H
04H
Set Output C - Reset A, B, D
00H
05H
Set Output A, C - Reset B, D
00H
06H
Set Output B, C - Reset A, D
00H
07H
Set Output A, B, C - Reset D
00H
08H
Set Output D - Reset A, B, C
00H
09H
Set Output A, D - Reset B, C
00H
0AH
Set Output B, D - Reset A, C
00H
0BH
Set Output A, B, D - Reset C
00H
0CH
Set Output C, D - Reset A, B
00H
0DH
Set Output A, C, D - Reset B
00H
0EH
Set Output B, C, D - Reset A
00H
0FH
Set Output A, B, C, D
Field
Remarks
Command
Command number in hex preceded by AAH
Output Pattern
Hex value for the bit output settings
Message Terminator
FFFFH
60
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
The following example sets Output B only and resets A, C, and D.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
10H
Perform Command 10
AAH
10H
Command echo
00H
02H
Set Output B
FFH
FFH
Message Terminator
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
61
ABxS Command 11 (11H): Input Status
DESCRIPTION
Retrieves the input line levels.
DISCUSSION
This command uses bit logic to monitor the levels of the digital input lines.
The four least significant bits display the input levels; 1 = ON and 0 = OFF.
The following chart shows the hex values for all input conditions that can be
returned in the second word of the response.
MSB
LSB
Remarks
LSB Bit 3
Input D
LSB Bit 2
Input C
LSB Bit 1
Input B
LSB Bit 0
Input A
00H
00H
00H
01H
Inputs A, B, C, D, OFF
Input A, ON - B, C, D, OFF
00H
00H
02H
Input B, ON - A, C, D, OFF
03H
Input A, B, ON - C, D, OFF
00H
04H
Input C, ON - A, B, D, OFF
00H
05H
Input A, C, ON - B, D, OFF
00H
06H
Input B, C, ON - A, D, OFF
00H
07H
Input A, B, C, ON - D, OFF
00H
08H
Input D, ON - A, B, C, OFF
00H
09H
Input A, D, ON - B, C, OFF
00H
0AH
Input B, D, ON - A, C, OFF
00H
0BH
Input A, B, D, ON - C, OFF
00H
0CH
Input C, D, ON - A, B, OFF
00H
0DH
Input A, C, D, ON - B, OFF
00H
0EH
Input B, C, D, ON - A, OFF
00H
0FH
Input A, B, C, D, ON
Field
Remarks
Command
Command number in hex preceded by AAH
Message Terminator
FFFFH
62
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
The following example shows only Input B is ON.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
11H
Perform Command 11
AAH
11H
Command echo
FFH
FFH
Message Terminator
00H
02H
Input B ON
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
63
ABxS Command 84 (84H): Fill Tag All
DESCRIPTION
Fill all RFID tags-in-field or all tags in the same family with a one byte
value over multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses. All tags
present in the antenna field with the specified Family ID will be affected by
this command.
The fill function requires one data value byte, a starting address, and a fill
length. It will then proceed to fill the tag with the data value byte, starting at
the specified start address for the specified number of consecutive bytes.
The Fill Length must be set to a non-zero value (1-48). The timeout value is
given in 1 msec increments and can have a value of 1EH to FFFEH (65,534
ms). When the Anticollision Index is not zero (multiple tag-in-field enabled), the LRP820 will return a response after the timeout expires. If the
Anticollision Index is 0, a response is returned when a successful operation
is performed on 1 tag or when the timeout has expired. When the timeout is
set to 0, the LRP820 will return a syntax error.
Field
Remarks
Command
Command number in hex preceded by AAH
Family Code
Tag Family ID - 00H = all tags
Anticollision index
Number of tags expected in field
Start Address
The tag address where the fill will start
Fill Length
The number of tag addresses to be filled (1-48)
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Data Value Byte
The byte to be used as fill
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
64
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
A response to a successful command will follow this form.
Field
Remarks
Command Echo
Command number in hex preceded by AAH
Number of Tags filled
Number of tags found in the field and filled
Command Status
One byte Error status
Message Terminator
FFFFH
EXAMPLE
Writes 'A' (41H) to all tags of family 01H, starting at tag address 0005H for
the following next consecutive 40 bytes with four to eight tags expected in
the field.. A timeout of 2 seconds (07D0H = 2000 x 1 msec increments) is
set for the completion of the Fill All Tag. The Anticollision Index is set to 2
so 4 to 8 tags will be expected. Four tags are successfully filled within the
timeout.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
84H
Perform Command 84
AAH
84H
Command Echo
01H
02H
Tag Family 01/ Index 2
04H
08H
Ntag/Status
00H
05H
Start Address
FFH
FFH
Message Terminator
00H
28H
Fill Length
07H
D0H
Timeout
00H
41H
Fill byte
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
65
ABxS Command 85 (85H): Block Read All
DESCRIPTION
Read a block of data from all RFID tags-in-field or those with the specified
Family ID.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host with one command. The timeout value is given in 1 msec increments
and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is
set to 0, the LRP820 will return a syntax error message 21H.
The Block Read All consists of Tag Family ID and an Anticollision Index, a
start address and length, followed by a timeout value and the message terminator, FFFFH. If the read length exceeds the last tag address, the LRP820
will return a syntax error message 21H.
The data read from the tag is returned in the LSB of the register, and the
MSB is always 00H.
A special termination packet (AAH FFH) is sent after the timeout expires.
When the Anticollision Index is not zero (multiple tag-in-field enabled), the
LRP820 will return a response after the timeout expires. If the Anticollision
Index is 0, the command returns a response after the successful operation on
one tag or when the timeout expires. No termination packet is sent when the
Anticollision Index is set to 0.
Field
Remarks
Command
Command number in hex preceded by AAH
Tag Family
Tag Family ID - 00H = all tags
Anticollision index
Number of tags expected in field
Start Address
The tag address where the read will start
Read Length
The number of tag addresses to be read
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
66
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Reads 4 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Read All. The Family ID byte is set to zero so all tags will be read.
The Anticollision Index is set to 2, so 4 to 8 tags will be expected. Three
tags respond with read data.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
Remarks
85H
Command Echo/Tag 1
LSB
AAH
85H
Perform Command 85
AAH
00H
02H
Tag Family 00/ Index 2
00H
30H
Data byte 1/Tag 1
00H
01H
Start Address
00H
31H
Data byte 2/Tag 1
00H
04H
Read Length
00H
32H
Data byte 3/Tag 1
07H
D0H
Timeout
00H
33H
Data byte 4/Tag 1
FFH
FFH
Message Terminator
FFH
FFH
Terminator/ Tag 1
AAH
85H
Command Echo/Tag 2
00H
40H
Data byte 1/Tag 2
00H
41H
Data byte 2/Tag 2
00H
42H
Data byte 3/Tag 2
00H
43H
Data byte 4/Tag 2
FFH
FFH
Terminator/ Tag 2
AAH
85H
Command Echo/Tag 3
00H
34H
Data byte 1/Tag 3
00H
35H
Data byte 2/Tag 3
00H
36H
Data byte 3/Tag 3
00H
37H
Data byte 4/Tag 3
FFH
FFH
Terminator/ Tag 3
AAH
FFH
Termination Packet
03H
08H
Ntag/Status
FFH
FFH
Terminator Message
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
67
ABxS Command 86 (86H): Block Write All
DESCRIPTION
Write a block of data to all RFID tags or all tags with the same Family ID.
DISCUSSION
This command is used to write segments of data to contiguous areas of tag
memory. It is capable of transferring up to 48 bytes of data transferred from
the Host with one command. The timeout value is given in 1 msec increments and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The Block Write consists of a Tag Family ID and an Anticollision Index,
start address followed by the data stream to be written to the RFID tag. If the
write range exceeds the last tag address, the LRP820 will return error message 21H, invalid format.
The data to be written to the tag is contained in the LSB of the register, and
the MSB is always 00H.
The LRP820 returns a response when the timeout expires. If the
Anticollision Index is 0 the command returns a response after the successful
operation on 1 tag, or when the timeout expires.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
The tag address where the write will start
Write Length
The number of tag addresses to be written to in bytes
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Write Data
The data to be written (1-48 bytes)
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
68
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Writes 4 bytes of data, starting at address 0001H. A timeout of 2 seconds
(07D0H = 2000 x 1 msec increments) is set for the completion of the Block
Write. The Family ID byte is set to 2, so all tags with Family ID of 2 will be
written to (four tags in this example). The Anticollision Index is set to 2, so
4 to 8 tags are expected in the field.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
86H
Perform Command 86
AAH
86H
Command Echo
02H
02H
Tag Family/ Index 2
04H
08H
Ntags/Status
00H
01H
Start Address
FFH
FFH
Message Terminator
00H
04H
Write Length
07H
D0H
Timeout
00H
40H
Data byte 1
00H
41H
Data byte 2
00H
42H
Data byte 3
00H
43H
Data byte 4
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
69
ABxS Command 87 (87H): Read Tag SN All
DESCRIPTION
This command retrieves the 8-byte tag serial number from all tags or those
with the specified Family ID number.
DISCUSSION
Each LRP tag has an unique (264 possible numbers) serial number. This
number cannot be changed and is not part of the 48 available data bytes. The
tag serial number is returned in the LSB only, with the MSB as 00H.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error. A special termination packet (starting with AAH FFH)
is sent when the timeout expires. If the Anticollision Index is 0, a response is
returned after successful operation to 1 tag or after the timeout has expired.
No termination packet is sent after a successful operation when the
Anticollision Index set to 0.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags-in-field expected
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
70
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
This example will read the 8-byte serial number from Tag Family 2. The
Anticollision Index of 1 sets the number of expected tags at 2-4. In this
example the ID for the found tag is 1E6E3CD200000000H in hexadecimal.
Multiple tags will return a complete response packet for each tag.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
LSB
Remarks
AAH
87H
Perform Command 87
AAH
87H
Command Echo
01H
01H
Family ID/ Index 1
00H
1EH
First SN byte
07H
D0H
Timeout
00H
6EH
Second SN byte
FFH
FFH
Message Terminator
00H
3CH
Third SN byte
00H
D2H
Fourth SN byte
00H
00H
Fifth SN byte
00H
00H
Sixth SN byte
00H
00H
Seventh SN byte
00H
00H
Eighth SN byte
FFH
FFH
Message Terminator
AAH
FFH
Termination packet
01H
08H
Ntags/Status
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
71
ABxS Command 88 (88H): Tag Search All
DESCRIPTION
Check to see if there is an RFID tag in the LRP820 field.
DISCUSSION
This command will activate LRP820 to "look" for a tag in the RF field. As
soon as the LRP820 finds a tag it will return a command echo to the host.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error. If no tag is present, it will return an error message. See
Section 6.2 for more information on error codes.
The number of tags returned can be either 1 (tag found) or 0 (timeout expired without having found a tag).
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
EXAMPLE
Checks for an RFID tag in the RF field. A timeout of 1 seconds (07D0H =
2000 x 1 msec increments) is set for the completion of the Tag Search. The
Family ID is set for any tag, and the Anticollision Index is set to expect 2-4
tags. One tag is found and the command is successful.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
AAH
88H
Perform Command 88
AAH
88H
Command Echo
00H
01H
Family ID/Anticollision Index 1
01H
00H
Ntags/Status
07H
D0H
2 second Timeout
FFH
FFH
Message Terminator
FFH
FFH
Message Terminator
72
LSB
Remarks
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 89 (89H): EAS Set/Reset All
DESCRIPTION
Sets or resets the EAS feature in tag memory for all tags in range, and of the
specified Family, when the command is issued.
DESCRIPTION
The commands contains a 1 byte parameter that enables or Disables the
EAS feature in tags that receive the command. When the EAS Set/Reset All
command is issued, the LRP820 responds with the number of tags affected
(Ntag). If the LRP820 returns a 0 for Ntag, no tags were set or reset by the
command.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error.
When multiple tag-in-field is enabled (Anticollision Index is not 0), the
LRP820 will return a response when the timeout period expires. When multiple tag-in-field is disabled, the LRP820 will return a response when it reads
a tag or the timeout expires.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Set/Reset
1 = enable, 0 = disable
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
73
EXAMPLE
This example assumes that the tags-in-field are not enabled for the EAS
feature. It will enabled the EAS feature for tags with Family ID 09H. The
Anticollision Index is 2, so 4-8 tags are expected in the field. When the command is issued, 5 tags with Family ID 09H are found and enabled for EAS.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
LSB
Remarks
AAH
89H
Perform Command 89
AAH
89H
Command Echo
09H
02H
Family ID/Anticollision Index 2
05H
08H
Ntags/Status
07H
D0H
Timeout
FFH
FFH
Message Terminator
00H
01H
Enable EAS
FFH
FFH
Message Terminator
74
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 8A (8AH): EAS Start/Stop
DESCRIPTION
If are using the EAS feature in your application, the EAS Start/Stop command enters and exits the LRP820 from EAS mode.
DISCUSSION
When EAS mode has been started, the LRP820 will return a response when
one or more EAS-enabled tags have entered the antenna field. It will send a
second response when all EAS-enabled tags have exited the field. The command contains a control byte that toggles EAS: 1 = start, 0 = stop. A Family
ID can be set so that only EAS-enabled tags from the specified Family trigger EAS responses. The Anticollision Index is ignored and should be set to
00H for this command.
The EAS mode also controls the CONFIG, ERROR and RF LEDs. The following table explains LED behavior.
LED(s)
Behavior
Description
CONFIG,
ERROR,
RF LED
OFF
No EAS-enabled tag in field
CONFIG LED BLINK
EAS-enabled tag entered field.
RF LED
ON
EAS tag has been read. LED will remain ON until all EAS tags have left
the field.
ERROR LED
BLINKS
Last EAS tag left the field.
IMPORTANT:
EAS mode prevents any other commands from being acknowledged or
executed until EAS has been stopped.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Start/Stop
1 = start, 0 = stop
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
75
EXAMPLE
This example starts EAS mode. Three responses follow. The first is a command acknowledgment. The LRP820 sends the second when the first
EAS-enabled tag enters the field, A third response is sent when field is clear
of EAS-enabled tags. Family ID is set to 0 so that any EAS-enabled tag will
trigger responses.
Command from Host
ACT Response from LRP820
MSB
Remarks
MSB
LSB
LSB
Remarks
AAH
8AH
Perform Command 8A
AAH
8AH
Command Echo
00H
00H
Family ID/null byte
FFH
00H
Ntag/Status
00H
01H
Start/Stop
FFH
FFH
Message Terminator
FFH
FFH
Message Terminator
When an EAS-enabled tag enters the antennas’ field, the LRP820 responds
with an EAS tag-in-field response.
Tags-in-Field Response from LRP820
MSB
LSB
Remarks
AAH
8AH
Command Echo
01H
00H
Ntag/Status
FFH
FFH
Message Terminator
When all EAS-enabled tags have left the field, the LRP820 will send the following response.
EAS Tags Left Field
Response from LRP820
MSB
LSB
AAH
8AH
Command Echo
00H
00H
Ntag/Status
FFH
FFH
Message Terminator
76
Remarks
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 8D (8DH): Continuous Read All
DESCRIPTION
Starts and stops Continuous Read All mode for multiple tags.
DISCUSSION
Continuous Read All mode is set by the length byte. To start Continuous
Read All mode send the command with valid, non-zero value for the length
of the read (1-48). Stop the mode by sending the command with a read
length of 0.
While in this mode, any other command can be issued and it will be handled
properly. After processing the new command, the LRP820 will resume the
Continuous Read All mode.
The command has a parameter, tag delay, that can prevent multiple reads of
the same tag. A tag is not read a second time until a specified number of
tags have been read since it was last read. Allowed value are from 0 to 255
(FFH), where 0 means the tag can be re-read anytime. When Continuous
Read All mode is interrupted with other commands, the tag delay count is
stopped during execution of the other commands and then resumed.
The LRP820 will respond with an acknowledge packet followed by data
packets for each tag read.
CONFIG LED blinks after each packet transmission.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
Tag address for the start of the read
Read Length
1-48 = start, 0 = stop
Tag Delay
Number of tag that must be read before the same tag will be read again
(0-255)
Message Terminator
FFFFH
NOTE:
This command can not be used over a MUX32 interface.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
77
EXAMPLE
Reads 4 bytes of data from the tag starting at address 0001H. The Family ID
byte is set to zero so all tags will be read. The Anticollision Index is set to 2
so 4 to 8 tags will be expected. The Tag Delay is set to 20 (14H). Three tags
respond with read data.
Command from Host
ACK Response from LRP820
MSB
Remarks
MSB
LSB
Remarks
LSB
AAH
8DH
Perform Command 8D
AAH
8DH
Command Echo
00H
02H
Tag Family 00/ Index 2
FFH
FFH
Message Terminator
00H
01H
Start Address
00H
04H
Read Length
00H
14H
Tag Delay
FFH
FFH
Message Terminator
After the LRP820 sends the acknowledgment, it will send the read data from
the 3 tags.
Data response from LRP820
MSB
LSB
AAH
8DH
Command Echo/Tag 1
00H
30H
Data byte 1/Tag 1
00H
31H
Data byte 2/Tag 1
00H
32H
Data byte 3/Tag 1
00H
33H
Data byte 4/Tag 1
FFH
FFH
Terminator/ Tag 1
AAH
8DH
Command Echo/Tag 2
00H
40H
Data byte 1/Tag 2
00H
41H
Data byte 2/Tag 2
00H
42H
Data byte 3/Tag 2
00H
43H
Data byte 4/Tag 2
FFH
FFH
Terminator/ Tag 2
AAH
8DH
Command Echo/Tag 3
00H
34H
Data byte 1/Tag 3
00H
35H
Data byte 2/Tag 3
00H
36H
Data byte 3/Tag 3
00H
37H
Data byte 4/Tag 3
FFH
FFH
Terminator/ Tag 3
78
Remarks
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 8E (8EH): Memory Lock All
DESCRIPTION
This command “locks” tag addresses in four byte blocks. Once bytes are
locked, they can not be unlocked.
DISCUSSION
The memory can be locked only in 4-byte blocks. The command passes a
two byte word with bits assigned to 4-byte blocks that can be locked. Remaining bits can lock the EAS feature and the lock configuration itself.
When multiple tag-in-field is enabled (Anticollision Index is not 0), the
LRP820 will return a response when the timeout period expires. When multiple tag-in-field is disabled, the LRP820 will return a response when it locks
bytes or the timeout expires.
Attempting to write to locked bytes will return a write timeout error in the
status byte. If you write to addresses that contain both locked and
non-locked bytes, the LRP820 will return a write error in the status byte.
The configuration word formatted as shown below.
Byte
LockLSB
LockMSB
Bit
Description
Tag bytes 0-3
Tag bytes 4-7
Tag bytes 8-11
Tag bytes 12-15
Tag bytes 16-19
Tag bytes 20-23
Tag bytes 24-27
Tag bytes 28-31
Tag bytes 32-35
Tag bytes 36-39
10
Tag bytes 40-43
11
Tag bytes 44-47
12
Lock Configuration
13
Lock EAS feature
14
Reserved
15
Reserved
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
79
If a bit in the configuration word is set, then the corresponding block in the
tag is locked when the command is issued. If a bit in the configuration word
is cleared (0), then the corresponding block will not change. Once locked, a
block can not be unlocked.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error.
The command is formatted as shown below.
Field
Remarks
Command
Command number in hex preceded by AAH
Family Code
Tag Family ID - 00H = all tags
Anticollision index
Number of tags-in-field expected
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
LockMSB
Bits 8-15 of the configuration word
LockLSB
Bits 0-7 of the configuration word
Message Terminator
FFFFH
EXAMPLE
This example will lock bytes 0-3 on all tags-in-field with the Family ID of
02H. Two tags are found and locked.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
Remarks
LSB
AAH
8EH
Perform Command 8E
AAH
8EH
Command Echo
02H
01H
Family ID/anticollision Index
02H
08H
Ntag/Status
07H
D0H
2 second timeout
FFH
FFH
Message Terminator
00H
01H
Lock Configuration
FFH
FFH
Message Terminator
80
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 94 (94H): SN Fill
DESCRIPTION
Fills only the RFID tag specified by serial number with a one byte value
over multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses. Only
the tag with the specified serial number will be affected by this command.
The LRP820 will return a response after the successful fill operation or
when the timeout expires.
The fill function requires a Family ID and an Anticollision Index, one data
value byte, a starting address, and a fill length. Then the command lists the
serial numbers of the tag to be filled. It fills the specified tag with the data
value byte, starting at the specified start address for the specified number of
consecutive bytes. When Fill Length is set to 0, the LRP820 will write fill
data from the start address to the end of the tags memory.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error. It returns a response when done or when the timeout
expires.
Field
Remarks
Command
Command number in hex preceded by AAH
Family Code
Tag Family ID - 00H = all tags
Anticollision index
Number of tags-in-field expected
Start Address
The tag address where the fill will start
Fill Length
The number of tag addresses to be filled
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Tag Serial Number
The 8-byte serial number
Data Value Byte
The byte used to fill
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
81
A response to a successful command will follow this form.
Field
Remarks
Command Echo
Command number in hex preceded by AAH
Number of Tags filled
0 = tag not found, 1 = tag filled
Command Status
One byte Error status
Message Terminator
FFFFH
EXAMPLE
Writes 'A' (41H) to a single tag, starting at tag address 0005H for the following next consecutive 40 bytes. The Family ID is turned off and the
Anticollision Index is set to expect 2-4 tags. A timeout of 2 seconds (07D0H
= 2000 x 1 msec increments) is set for the completion of the configuration.
Command from Host
Response from Host
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
94H
Perform Command 94
AAH
94H
Command Echo
00H
01H
Family ID/ Index 1
01H
00H
Ntag/Status
00H
05H
Start Address
FFH
FFH
Message Terminator
00H
28H
Fill Length
07H
D0H
Timeout
00H
01H
SN byte 1
00H
ACH
SN byte 2
00H
42H
SN byte 3
00H
D0H
SN byte 4
00H
27H
SN byte 5
00H
1CH
SN byte 6
00H
65H
SN byte 7
00H
33H
SN byte 8
00H
41H
Fill byte
FFH
FFH
Message Terminator
82
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 95 (95H): SN Block Read
DESCRIPTION
Read a block of data from a specified RFID tag.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host with one command if there is no tag Family ID. The timeout value is
given in 1 msec increments and can have a value of 1EH to FFFEH (65,534
ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The SN Block Read consists of Family ID and an Anticollision Index, a start
address and length, followed by a timeout value. The 8-byte serial number of
the target tag is specified. If the read length exceeds the last tag address, the
LRP820 will return error message in the status byte. It returns a response
when done or when the timeout expires.
The data read from the tag is returned in the LSB of the register, and the
MSB is always 00H. A special error packet (AAH FFH) is sent if the timeout expires.
Field
Remarks
Command
Command number in hex preceded by AAH
Tag Family
Tag Family ID - 00H = all tags
Anticollision index
Number of tags expected
Start Address
The tag address where the read will start
Read Length
The numbers of tag addresses to be read
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Tag Serial Number
8-byte tag serial number
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
83
EXAMPLE:
Reads 4 bytes of data from the tag specified by serial number starting at
address 0001H. A timeout of 2 seconds (07D0H = 2000 x 1 msec increments) is set for the completion of the SN Block Read. The Family ID byte
is set to zero. The Anticollision Index is set to 2, expecting 4-8 tags in the
field.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
AAH
95H
Perform Command 95
AAH
95H
Command Echo
00H
02H
Tag Family 00/ Index 2
00H
30H
Data byte 1
00H
01H
Start Address
00H
31H
Data byte 2
00H
04H
Read Length
00H
32H
Data byte 3
07H
D0H
Timeout
00H
33H
Data byte 4
00H
ABH
SN byte 1
01H
00H
Ntag/Status
00H
02H
SN byte 2
FFH
FFH
Message Terminator
00H
F3H
SN byte 3
00H
55H
SN byte 4
00H
C5H
SN byte 5
00H
2DH
SN byte 6
00H
41H
SN byte 7
00H
A0H
SN byte 8
FFH
FFH
Message Terminator
84
Remarks
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 96 (96H): SN Block Write
DESCRIPTION
Write a block of data to a single RFID tag specified by its serial number.
DISCUSSION
This command is used to write segments of data to contiguous areas of tag
memory. It is capable of transferring up to 48 bytes of data transferred from
the Host with one command. The timeout value is given in 1 msec increments and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The SN Block Write consists of a Family ID, Anticollision Index, and start
address followed by the data stream to be written to the RFID tag. If the
write range exceeds the last tag address, the LRP820 will return an error
message 21H, invalid format. It returns a response when done or when the
timeout expires.
The data to be written to the tag is contained in the LSB of the register, and
the MSB is always 00H.
Field
Remarks
Command
Command number in hex preceded by AAH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
The tag address where the write will start
Write Length
The number of tag addresses to be written to
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Tag Serial Number
8-byte tag serial number
Write Data
The data to be written (1-48 bytes)
Message Terminator
FFFFH
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
85
EXAMPLE:
Writes 4 bytes of data, starting at address 0001H. A timeout of 2 seconds
(07D0H = 2000 x 1 msec increments) is set for the completion of the Block
Write. The Family ID byte is set to 0 and the Anticollision Index is set to 2
for this example, meaning the LRP820 will be expecting 4-8 tags in the
field.
Command from Host
Response from LRP820
MSB
Remarks
MSB
LSB
Remarks
96H
Command Echo
LSB
AAH
96H
Perform Command 96
AAH
02H
02H
Tag Family 02/ Index 2
01H
00H
Ntags/Status
00H
01H
Start Address
FFH
FFH
Message Terminator
00H
04H
Write Length
07H
D0H
Timeout
00H
A4H
SN byte 1
00H
6CH
SN byte 2
00H
18H
SN byte 3
00H
92H
SN byte 4
00H
2DH
SN byte 5
00H
34H
SN byte 6
00H
DEH
SN byte 7
00H
20H
SN byte 8
00H
40H
Data byte 1
00H
41H
Data byte 2
00H
42H
Data byte 3
00H
43H
Data byte 4
FFH
FFH
Message Terminator
86
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxS Command 97 (97H): SN Block Read All
DESCRIPTION
Read a block of data from all RFID tags-in-field or those with the specified
Family ID. Returns the serial number of the tags read, along with tag data.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host with one command if there is no tag family ID. The timeout value is
given in 1 msec increments and can have a value of 1EH to FFFEH (65,534
ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The response to this command will contain the serial number of the responding tags preceding the data from those tags. The termination packet is transmitted when the timeout expires. Each packet will be sent to the host as soon
as it is available. The returned serial numbers can be used to read/write to
tags-in-field via the SN Block Read/Write command.
The SN Block Read All consists of Family ID, Anticollision Index, a start
address and length, followed by a timeout value and the message terminator,
FFFFH. A special termination packet is sent when the timeout expires. If the
Anticollision Index is 0, a response is returned when the operation is successfully completed on 1 tag, or when the timeout expires. A termination
packet is not sent for successful completion if the Anticollision Index is 0.
If the read length exceeds the last tag address, the LRP820 will return an
invalid format error message (error code 21H).
Field
Remarks
Command
Command number in hex preceded by AAH
Tag Family
Tag Family ID - 00H = all tags
Anticollision index
Number of tags expected
Start Address
The tag address where the read will start
Read Length
The numbers of tag addresses to be read
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Message Terminator
FFFFH
NOTE:
This command can not be used with a MUX32 interface.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
87
EXAMPLE:
Reads 2 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the SN Block Read All. The Family ID byte is set to zero so all tags will be
read. The Anticollision Index is set to 2 so 4-8 tags are expected. Two tags
respond with read data.
Command from Host
Response from LRP820
MSB
LSB
Remarks
MSB
LSB
Remarks
AAH
97H
Perform Command 97
AAH
97H
Command Echo/Tag 1
00H
02H
Tag Family 00/ Index 2
00H
10H
SN byte 1/Tag 1
00H
01H
Start Address
00H
43H
SN byte 2/Tag 1
00H
02H
Read Length
00H
6CH
SN byte 3/Tag 1
07H
D0H
Timeout
00H
73H
SN byte 4/Tag 1
FFH
FFH
Message Terminator
00H
92H
SN byte 5/Tag 1
00H
C0H
SN byte 6/Tag 1
00H
D6H
SN byte 7/Tag 1
00H
54H
SN byte 8/Tag 1
00H
30H
Data byte 1/Tag 1
00H
31H
Data byte 2/Tag 1
FFH
FFH
Terminator/ Tag 1
88
AAH
97H
Command Echo/Tag 2
00H
08H
SN byte 1/Tag 2
00H
0AH
SN byte 2/Tag 2
00H
81H
SN byte 3/Tag 2
00H
18H
SN byte 4/Tag 2
00H
23H
SN byte 5/Tag 2
00H
CCH
SN byte 6/Tag 2
00H
D0H
SN byte 7/Tag 2
00H
EFH
SN byte 8/Tag 2
00H
40H
Data byte 1/Tag 2
00H
41H
Data byte 2/Tag 2
FFH
FFH
Terminator/ Tag 2
AAH
FFH
Command end
02H
08H
Ntags/Status
FFH
FFH
Message Terminator
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
6.5 ABx
ABx Fast
Fast Protocol
Protocol
6.4
The difference from the standard ABx are:
The command/response packet contains the packet size
You can include a checksum in the command
The headers and terminator are ASCII characters
Since ABx Fast is a binary protocol, the Xon/Xoff handshake
cannot be used.
ABx Command Packet Structure:
The command protocol is based on the following minimal packet structure.
The data field and the checksum may not be present depending on the command type and your checksum setting.
Field
Number of Bytes Content
Header
 (02H, 02H)
Command Size
Packet length in bytes excluding the header, command
size, checksum and terminator bytes.
Command Code
Command
(Data)
variable
command data/parameters
(Checksum)
Optional Checksum
Terminator
 (03H)
Following a successful operation, the LRP820 will respond with the following. The data field and the checksum may not be present depending on your
checksum setting.
Field
Number of Bytes Content
Header
 (02H, 02H)
Response Size
Packet length in bytes excluding the header, response
size, checksum and terminator bytes.
Command Echo
Command
(Data)
variable
response data
(Checksum)
Optional Checksum
Terminator
 (03H)
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
89
If the LRP820 Reader/Writer encounters a fault it will respond with the following:
Field
Number of Bytes Content
Header
 (02H, 02H)
Response Size
Packet length in bytes excluding the header, packet
size, checksum and terminator bytes.
Error Flag
FFH
Error Code
Hex error code, see Table 7 for details
(Checksum)
Optional Checksum
Terminator
 (03H)
The Header and Terminator are always STX-STX and ETX
respectively.
All other bytes are interpreted as binary data (0 - 255 dec).
Fields with two bytes are sent most significant byte (MSB)
first.
The sequence for each command is given with the response format in the
following section.
Command/Response Size
The ABx Fast requires that the length of the packet be included in the command. All parameters and data between the Command/Response Size and
the Checksum or Terminator bytes must be accounted for in the command/response size word. This includes all command codes and parameters
such as field definitions for Block Read/Writes. The command/response size
will be the same with, or without, a checksum.
90
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Checksum
The optional checksum must be enabled from the operating mode menu to
be available. The checksum is calculated by adding all the byte values in the
packet (less the values in the header, checksum if present, and terminator),
discarding byte overflow and subtracting the byte sum from FFH. Thus,
when the packet length through the checksum are added as byte values, the
sum will be FFH.
EXAMPLE
The following is a typical command using a checksum.
Command from Host
Field
Contents
Header

02H
Command Size
00H
02H
03H
Command Code
Timeout
Sum these values to calculate
the checksum
01H
07H
D0H
Checksum
24H
Terminators 
03H
The summed values begin with the Command Size and end with the timeout
value. That sum, less overflow, is subtracted from FFH for the checksum
value.
Thus: 00 + 03 + 01 +07 + D0 = DB
FF - DB = 24H
The optional Checksum is included in the following command explanations.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
91
ABxF Command 4 (04H): Fill Tag
DESCRIPTION
Fill an RFID tag with a one byte value over multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses.
The fill function requires one data value byte, a starting address, and a fill
length. It will fill the tag with the data value byte, starting at the specified
start address for the specified number of consecutive bytes. When Fill
Length is set to 0, the LRP820 will write fill data from the start address to
the end of the tag’s memory. The timeout value is given in 1 msec increments and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will return a syntax error.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0008H for this command
Command
04H
Start Address
2-byte value for the starting tag address
Fill Length
2-byte value for the length of the fill in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Data value byte
1 byte of fill
Checksum
Optional Checksum
Terminator

A response to a successful command will follow this form.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
04H
Checksum
Optional Checksum
Terminator

92
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
Writes 'A' (41H) to the tag starting at address 0005H for the following next
consecutive 40 bytes. A timeout of 2 seconds (07D0H = 2000 x 1 msec increments) is set for the completion of the configuration.
Response from LRP820
Command from Host
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
04H
02H
02H
01H
08H
Command Code
04H
Command Echo
Start address
00H
Checksum
FAH
05H
Terminators 
03H
Block Size
00H
28H
Timeout,
2 seconds
07H
Data Value Byte
41H
D0H
Checksum
AEH
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
93
ABxF Command 5 (05H): Block Read
DESCRIPTION
Reads a block of data from an RFID tag.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host. The timeout value is given in 1 msec increments and can have a value
of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820
will return a syntax error.
The Block Read consists of a start address and length, followed by a timeout
value and a message terminator as shown below.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0007H for this command
Command
05H
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the read in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

94
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Reads 4 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Read.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
07H
02H
05H
Command Code
05H
Command Echo
05H
Start address
00H
Data from
address 0001H
05H
Data from
address 0002H
AAH
Data from
address 0003H
E7H
Data from
address 0004H
0AH
01H
Block size
00H
04H
Timeout,
2 seconds
07H
Checksum
17H
Terminator 
03H
D0H
Checksum
55H
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
95
ABxF Command 6 (06H): Block Write
DESCRIPTION
Write a block of data to an RFID tag.
DISCUSSION
The Block Write command is used to write segments of data to contiguous
areas of tag memory. It is capable of handling up to 48 bytes of data transferred to the host. The timeout value is given in 1 msec increments and can
have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0,
the LRP820 will return a syntax error.
The Block Write command consists of a start address followed by the data to
be written to the RFID tag. If the write range exceeds the last tag address,
the LRP820 will return an invalid format error message (error code 21H).
Field
Content
Header

Packet Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0007H plus the number of data bytes
Command
06H
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the write in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Data
Data bytes to be written
Checksum
Optional Checksum
Terminator

96
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Writes 4 bytes of data to the tag starting at address 0000H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Write.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
0BH
02H
01H
Command Code
06H
Command Echo
06H
Start address
00H
Checksum
F8H
00H
Terminators 
03H
Block Size
00H
04H
Timeout,
2 seconds
07H
Data to write to
address 0000H
52H
Data to write to
address 0001H
46H
Data to write to
address 0002H
49H
Data to write to
address 0003H
44H
D0H
Checksum
EEH
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
97
ABxF Command 7 (07H): Read Tag Serial Number
DESCRIPTION
This command retrieves the 8-byte tag serial number.
DISCUSSION
Each LRP tag has an unique (264 possible numbers) serial number. This
number can not be changed and is not part of the 48 available data bytes.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0003H for this command
Command
07H
Timeout
2-byte timeout value in 1 ms increments (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

98
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
This example will wait until a tag is in range and then reads the 8-byte serial
number. In this example the ID is 1E6E3DC200000000 in hexadecimal.
Response from LRP820
Command from Host
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
02H
02H
09H
03H
Command Code
07H
Command Echo
07H
Timeout
07H
First ID byte
1EH
D0H
Second ID byte
6EH
Checksum
1EH
Third ID byte
3DH
Terminators 
03H
Fourth ID byte
C2H
Fifth ID byte
00H
Sixth ID byte
00H
Seventh ID byte
00H
Eighth ID byte
00H
Checksum
64H
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
99
ABxF Command 8 (08H): Tag Search
DESCRIPTION
Checks for an RFID tag in the LRP820 field.
DISCUSSION
This command will activate the reader/write to "look" for a tag in the RF
field. If the LRP820 finds a tag it will return a command echo to the host.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the timeout is set to 0, the LRP820 will
return a syntax error. If no tag is present it will return an error message. See
Section 6.2 for information on the error messages.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0003H for this command
Command
08H
Timeout
2-byte value for the time in 1 ms units (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

EXAMPLE
Checks for an RFID tag in the RF field. A timeout of 2 seconds (07D0H =
2000 x 1 msec increments) is set for the completion of the Tag Search.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
Command Code
08H
Command Echo
Timeout
07H
Checksum
F6H
D0H
Terminators 
03H
03H
Checksum
1DH
Terminators 
03H
100
02H
01H
08H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxF Command D (0DH): Continuous Block Read
DESCRIPTION
Sends block reads continuously to any tag in range of the antenna. When a
tag enters the RF field, it is read and the data passed to the host computer.
The LRP820 continues to read the tag but will not send the same data to the
host until the tag has been outside the RF field for a specified time period.
This Delay Between Identical Decodes parameter prevents redundant data
transmissions when the LRP820 is in Continuous Block Read mode.
DISCUSSION
The initiate/cancel Continuous Block Read command contains three parameters: read length, start address, and delay between identical decodes. The
read length parameter switches the mode. Any valid, non-zero length will set
the LRP820 into Continuous Block Read mode. A read length value of 00H
will turn Continuous Block Mode off.
The Delay Between Identical Decodes parameter can have a value of 0 to 60
seconds. When the Delay Between Identical Decodes is set to 0, the LRP820
will continuously read AND transmit tag data to the host. This can flood the
buffers and cause communication errors and data loss.
If the LRP820 receives other commands from the host, it will execute them
and then resume Continuous Block Read mode. To exit Continuous Block
Read mode, issue the command with a read length of 0.
In Continuous Block Read mode, the LEDs will display as follows:
LED
Behavior
Description
ANT LED
ON
Assumes the Antenna is powered and functioning
CONFIG LED BLINK
Tag entered the RF field
RF LED
ON
A tag has been read and is still in the field
RF LED
OFF
A read tag has been out of range for the specified time
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
101
The command is formatted as follows.
Field
Content
Header

Command Size
Command length in bytes excluding the header, command size, checksum
and terminator bytes.
Command
0DH
Start Address
2 byte value for the start address in the tag
Read Length
2 byte value for the block read length
Delay Between Identical Delay value given in 1 second units
Reads
Checksum
Optional Checksum
Terminator

EXAMPLE
This example places the LRP820 in Continuous Block Read mode and reads
8 bytes of data from the tag starting at address 0001H. A delay between
identical reads of 2 seconds (0002H = 2 x 1 second increments) is set.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
Command Code
0DH
Command Echo
0DH
Start Address
00H
Checksum
F1H
01H
Terminator 
03H
06H
Read Length
02H
01H
00H
08H
Delay Between Identical 02H
Decodes
Checksum
E1H
Terminator 
03H
102
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The LRP820 will first return an acknowledgment of the command followed
by a response containing read data when a tag enters the antenna field.
Response from LRP820
Field
Contents
Header

02H
Command Size
00H
Command Echo
0DH
Data Byte 1
05H
Data Byte 2
AAH
Data Byte 3
E7H
Data Byte 4
0AH
Data Byte 5
05H
Data Byte 6
AAH
Data Byte 7
E7H
Data byte 8
0AH
Checksum
A9H
02H
09H
Terminator  03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
103
ABxF Command 10 (10H): Set Output
DESCRIPTION
Set the levels of the output lines and output LEDs "A" through "D."
DISCUSSION
This command is used to set the levels of the digital output lines using bit
logic. The four least significant bit toggle the output levels; 1 = ON and
0 = OFF. The following chart shows the hex values for all output high combinations. To reset all output, issue the command with 0000H for the Output
Pattern byte.
MSB
LSB
Remarks
LSB Bit 3 LSB Bit 2 LSB Bit 1 LSB Bit 0
Output D Output C Output B Output A
00H
00H
Reset A, B, C, D
00H
01H
Set Output A - Reset B, C, D
00H
02H
Set Output B - Reset A, C, D
00H
03H
Set Output A, B - Reset C, D
00H
04H
Set Output C - Reset A, B, D
00H
05H
Set Output A, C - Reset B, D
00H
06H
Set Output B, C - Reset A, D
00H
07H
Set Output A, B, C - Reset D
00H
08H
Set Output D - Reset A, B, C
00H
09H
Set Output A, D - Reset B, C
00H
0AH
Set Output B, D - Reset A, C
00H
0BH
Set Output A, B, D - Reset C
00H
0CH
Set Output C, D - Reset A, B
00H
0DH
Set Output A, C, D - Reset B
00H
0EH
Set Output B, C, D - Reset A
00H
0FH
Set Output A, B, C, D
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
10H
Output Pattern
1 byte representing the desired output settings in bits 0-3
Checksum
Optional Checksum
Terminator

104
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
The following example sets Output B only and resets A, C, and D.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
Command Code
10H
Command Echo
10H
Output Value Byte
02H
Checksum
EEH
Checksum
EBH
Terminator 
03H
Terminator 
03H
02H
02H
01H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
105
ABxF Command 11 (11H): Input Status
DESCRIPTION
Retrieves the input line levels.
DISCUSSION
This command is used to monitor the levels of the digital input lines using
bit logic. The four least significant bit toggle the input levels; 1 = ON and
0 = OFF. The following chart shows all possible conditions that can be
returned in the response.
MSB
LSB
Remarks
LSB Bit 3
Input D
LSB Bit 2
Input C
LSB Bit 1
Input B
LSB Bit 0
Input A
00H
00H
Inputs A, B, C, D, OFF
00H
00H
01H
Input A, ON - B, C, D, OFF
02H
Input B, ON - A, C, D, OFF
00H
03H
Input A, B, ON - C, D, OFF
00H
04H
Input C, ON - A, B, D, OFF
00H
05H
Input A, C, ON - B, D, OFF
00H
06H
Input B, C, ON - A, D, OFF
00H
07H
Input A, B, C, ON - D, OFF
00H
08H
Input D, ON - A, B, C, OFF
00H
09H
Input A, D, ON - B, C, OFF
00H
0AH
Input B, D, ON - A, C, OFF
00H
0BH
Input A, B, D, ON - C, OFF
00H
0CH
Input C, D, ON - A, B, OFF
00H
0DH
Input A, C, D, ON - B, OFF
00H
0EH
Input B, C, D, ON - A, OFF
00H
0FH
Input A, B, C, D, ON
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
11H
Checksum
Optional Checksum
Terminator

106
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
The following example shows only Input B is ON and A, C, and D are OFF.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
11H
Command Echo
11H
Checksum
EDH
Input Value Byte
02H
Terminator 
03H
Checksum
EAH
Terminator 
03H
02H
01H
Command Code
02H
02H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
107
ABxF Command 84 (84H): Fill All
DESCRIPTION
Fill all RFID tags-in-field or all tags in the same family, with a one byte
value over multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses. All tags
present in the antenna field with the specified Family ID will be affected by
this command.
The Fill All function requires one data value byte, a starting address, and a
fill length. It will fill the tag with the data value byte, starting at the specified
start address for the specified number of consecutive bytes. The Fill Length
must be set to a non-zero value (1-48).
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms). When the Anticollision Index is not zero (multiple tag-in-field enabled), the LRP820 returns a response after the timeout
expires. If the Anticollision Index is 0, a response is returned when a successful operation is performed on 1 tag or when the timeout has expired.
When the timeout is set to 0, the LRP820 will return a syntax error.
Field
Content
Header

Packet Size
Packet length in bytes excluding the header, packet size, checksum and terminator bytes. 0008H for this command
Command
84H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Fill Length
2-byte value for the length of the fill in number of bytes (1-48)
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Data value byte
1 byte of fill
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used over a MUX32 interface.
108
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
Writes 'A' (41H) to all tags with Family ID 03H, starting at address 0005H
for the following next consecutive 40 bytes. A timeout of 2 seconds (07D0H
= 2000 x 1 msec increments) is set for the completion of the configuration.
Four tags are found and filled successfully.
Command from Host
Response from LRP820
Field
Bytes Contents
Field
Bytes Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
0AH
02H
03H
Command Code
84H
Command Echo
84H
Family ID
03H
Numbers of tags
04H
Anticollision Index
02H
Status byte
08H
Start address
00H
Checksum
6CH
05H
Terminator 
03H
Fill Length
00H
28H
Timeout,
2 seconds
07H
Data Value Byte
41H
D0H
Checksum
27H
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
109
ABxF Command 85 (85H): Block Read All
DESCRIPTION
Read a block of data from all RFID tags-in-field or all those with the specified Family ID.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. The timeout value is given in 1 msec increments and can have a
value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the
LRP820 will return a syntax error.
The Block Read All consists of a Family ID, an Anticollision Index, a start
address and length, followed by a timeout value and a message terminator as
shown below.
If the read length exceeds the last tag address, the LRP820 will return an invalid format error message (error code 21H). A special termination packet is
sent when the timeout expires. If the Anticollision Index is set to 0, a
response is returned after successful completion of the operation to 1 tag, or
when the timeout expires. When the Anticollision Index is 0, no special
termination packet is sent after timeout.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
85H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the read in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used with a MUX32 interface.
110
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Reads 4 bytes of data from tags with Family ID AAH, starting at address
0001H. A timeout of 2 seconds (07D0H = 2000 x 1 msec increments) is set
for the completion of the Block Read All. The Tag Family byte is set to zero
so all tags will be read. The Anticollision Index is set to 2, expecting 4-8
tags. Two tags respond with data.
Response from LRP820
Command from Host
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
Field
02H
02H
03H
09H
Command Code
85H
Command Echo/Tag 1
85H
Family ID
AAH
Data from
address 0001H
05H
Data from
address 0002H
AAH
Checksum
C8H
Terminator 
03H
02H
Anticollision Index
02H
Start address
00H
01H
Block size
00H
02H
Timeout,
2 seconds
07H
Header

D0H
Checksum
EBH
Response Size
00H
Terminator 
03H
Command Echo/Tag 2
85H
Data from
address 0001H
05H
Data from
address 0002H
AAH
02H
03H
Checksum
C8H
Terminator 
03H
Header

02H
Response Size
00H
Command Status
FFH
Number of tags
02H
Status Byte
08H
02H
03H
Checksum
F3H
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
111
ABxF Command 86 (86H): Block Write All
DESCRIPTION
Write a block of data to an RFID tag.
DISCUSSION
The Block Write All command is used to write segments of data to contiguous areas of tag memory. The timeout value is given in 1 msec increments
and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is
set to 0, the LRP820 will return a syntax error.
The Block Write All consists of a Family ID, Anticollision Index, a start address followed by the data stream to be written to the RFID tag. If the write
range exceeds the last tag address, the LRP820 will return an invalid format
error message (error code 21H).
The LRP820 will return a response when the timeout expires. If the
Anticollision Index is 0, a response is returned when the operation is successfully completed on 1 tag, or when the timeout expires.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0009H plus the number of data bytes
Command
86H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the write in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Data
Data bytes to be written
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used over a MUX32 interface.
112
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Writes 4 bytes of data to the tag starting at address 0000H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the Block Write All. Family ID is set to 00H so all tags-in-field will be written to. The Anticollision Index is 4, expecting 32-64 tags. Five tags are
written to.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
0DH
02H
03H
Command Code
86H
Command Echo
86H
Family ID
00H
Number of Tags
05H
Anticollision Index
04H
Start address
00H
Status Byte
08H
00H
Checksum
69H
00H
Terminator 
03H
Block Size
04H
Timeout,
2 seconds
07H
Data to write to
address 0000H
52H
Data to write to
address 0001H
46H
Data to write to
address 0002H
49H
Data to write to
address 0003H
44H
Checksum
68H
Terminator 
03H
D0H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
113
ABxF Command 87 (87H): Read Tag SN All
DESCRIPTION
This command retrieves the 8-byte tag serial number from all tags-in-field or
those with the specified Family ID.
DISCUSSION
Each LRP tag has an unique (264 possible numbers) serial number. This
number can not be changed and is not part of the 48 available data bytes. A
special termination packet is sent when the timeout expires.
If the Anticollision Index is set to 0, a response is returned when the operation is successfully completed to 1 tag, or when the timeout expires. No special termination packet is sent upon successful completion if Anticollision
Index is set to 0.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0005H for this command
Command
87H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Timeout
2-byte timeout value in 1 ms increments (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used with a MUX32 interface.
114
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
This example will read the 8-byte serial number from all tags permitted by
the Family ID and Anticollision Index. In this example, one tag responds
and the serial number is 1E6E3DC200000000 in hexadecimal.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
05H
02H
09H
Command Code
87H
Command Echo
87H
Family ID
00H
SN byte 1
1EH
Anticollision Index
01H
SN byte 2
6EH
Timeout
07H
SN byte 3
3DH
D0H
SN byte 4
C2H
Checksum
9BH
SN byte 5
00H
Terminator 
03H
SN byte 6
00H
SN byte 7
00H
SN byte 8
00H
Checksum
E4H
Terminator 
03H
Header

02H
Response Size
00H
02H
03H
Command Status
FFH
Number of Tags
01H
Status Byte
08H
Checksum
F4H
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
115
ABxF Command 88 (88H): Tag Search All
DESCRIPTION
Check to see if there is any RFID tags in the LRP820 antenna field.
DISCUSSION
This command will activate the LRP820 to "look" for a tag in the RF field.
As soon as the LRP820 finds a tag it will return a command echo to the host.
The timeout value is given in 1 msec increments and can have a value of
1EH to FFFEH (65,534 ms).
When the timeout is set to 0, the LRP820 will return a syntax error. If no tag
is present it will return an error message. See Section 6.2 for information on
the error messages.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. 0005H for this command
Command
88H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Timeout
2-byte value for the time in 1 ms units (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used over a MUX32 interface.
116
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
Checks for an RFID tag in the RF field. A timeout of 2 seconds (07D0H =
2000 x 1 msec increments) is set for the completion of the Tag Search All.
A tag is found.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
02H
Command Size
00H
Response Size
00H
05H
02H
03H
Command Code
88H
Command Echo
88H
Family ID
00H
Number of Tags
01H
Anticollision Index
02H
Status byte
00H
Timeout
07H
Checksum
73H
D0H
Terminators 
03H
Checksum
99H
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
117
ABxF Command 89 (89H): EAS Set/Reset All
DESCRIPTION
Sets or resets the EAS feature in tag memory for all tags in range when the
command is issued.
DESCRIPTION
When the EAS Set/Reset All command is issued, the LRP820 will respond
with the number of tags affected. If the LRP820 return a 0 for Ntag it means
that no tags were set or reset by the command.
When multiple tag-in-field is enabled (Anticollision index is not 0), the
LRP820 will return a response when the timeout period expires. When multiple tag-in-field is disabled, the LRP820 will return a response when it reads
a tag or the timeout expires.
Field
Content
Header

Command Size
Command length in bytes excluding the header, command size, checksum
and terminator bytes.
Command
89H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Timeout
Timeout value given in 1 ms units (1EH - FFFEH)
Checksum
Optional Checksum
Message Terminator

118
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
This example assumes that the tags-in-field are not enabled for the EAS feature. It will enabled the EAS feature for tags with Family ID 09H. The
Anticollision Index is 2, so 4-8 tags are expected in the field. When the command is issued, 5 tags with Family ID 09H are found and enabled for EAS.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
02H
05H
02H
03H
Command Code
89H
Command Echo
Family ID
09H
Number of Tags
05H
Anticollision Index
02H
Status byte
08H
07H
Checksum
66H
D0H
Terminator 
03H
Timeout
Checksum
8FH
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
89H
119
ABxF Command 8A (8AH): EAS Start/Stop
DESCRIPTION
If are using the EAS feature in your application, the EAS Start/Stop command enters and exits the LRP820 from EAS mode.
DISCUSSION
When EAS mode has been started, the LRP820 will return a response when
one or more EAS-enabled tags have entered the antenna field. It will send a
second response when all EAS-enabled tags have exited the field. The command contains a control byte that toggles EAS: 1 = start, 0 = stop. A Family
ID can be set so that only EAS-enabled tags from the specified Family trigger EAS responses. The Anticollision Index is ignored and should be set to
00H for this command.
The EAS mode also controls the CONFIG, ERROR and RF LEDs. The following table explains LED behavior.
LED(s)
Behavior
Description
CONFIG,
ERROR,
RF LED
OFF
No EAS-enabled tag in field
CONFIG LED BLINK
EAS-enabled tag entered field.
RF LED
ON
EAS tag has been read. LED will remain ON until all EAS tags have left
the field.
ERROR LED
BLINKS
Last EAS tag left the field.
IMPORTANT:
EAS mode prevents any other commands from being acknowledged or executed until EAS has been stopped.
Field
Content
Header

Command Size
Command length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
8AH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Anticollision not considered for this command, 00H
Checksum
Optional Checksum
Message Terminator 
120
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
This example starts EAS mode. Three responses follow. The first is a command acknowledgment. The LRP820 sends the second when the first
EAS-enabled tag enters the field, A third response is sent when field is clear
of EAS-enabled tags. Family ID is set to 0 so that any EAS-enabled tag will
trigger responses.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
8AH
02H
03H
02H
03H
Command Code
8AH
Command Echo
Family ID
00H
Number of Tags
FFH
Anticollision Index
00H
Status byte
00H
Checksum
72H
Checksum
73H
Terminator 
03H
Terminator 
03H
When an EAS-enabled tag enters the antennas’ field, the LRP820 responds
with an EAS tag-in-field response.
Response from LRP820
Field
Contents
Header

02H
Response Size
00H
Command Echo
8AH
Number of Tags
01H
Status byte
00H
02H
03H
Checksum
71H
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
121
When all EAS-enabled tags have left the field, the LRP820 will send the following response.
Response from LRP820
Field
Contents
Header

02H
Response Size
00H
Command Echo
8AH
02H
03H
Number of Tags
00H
Status byte
00H
Checksum
72H
Terminator 
03H
122
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
ABxF Command 8D (8DH): Continuous Read All
DESCRIPTION
Starts and stops Continuous Read All mode for multiple tags.
DISCUSSION
Continuous Read All mode is set by the length byte. To start Continuous
Read All mode send the command with valid, non-zero value for the length
of the read (1-48). Stop the mode by sending the command with a read
length of 0. While in this mode, any other command can be issued and it
will be handled properly. After processing the new command, the LRP will
resume the Continuous Read All mode.
The command has a parameter, tag delay, that can prevent multiple reads of
the same tag. A tag is not read a second time until a specified number of
tags have been read since it was last read. Allowed value are from 0 up to
255 (FFH), where 0 means the tag can be re-read anytime. When Continuous Read All mode is interrupted with other commands, the tag delay count
is stopped during execution of the other commands and then resumed.
The LRP820 will respond with an acknowledge packet followed by data
packets for each tag read.
CONFIG LED blinks after each packet transmission.
Field
Content
Header

Command Size
Command length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
8DH
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Anticollision not considered for this command, 00H
Start Address
Tag address for the start of the read
Read Length
1-48 = start, 0 = stop
Tag Delay
Number of tags that must be read before the same tag will be read again (0-225)
Checksum
Optional Checksum
Message Terminator 
NOTE:
This command can not be used with a MUX32 interface>
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
123
EXAMPLE
Reads 4 bytes of data from the tag starting at address 0001H. The Family ID
byte is set to zero so all tags will be read. The Anticollision Index is set to 1
so 2 to 4 tags will be expected. The Tag Delay is set to 20 (14H). Two tags
respond with read data.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
Command Size
00H
Response Size
00H
Command Code
8DH
Command Echo
8DH
Family ID
00H
Checksum
71H
Anticollision Index
01H
Terminator 
03H
Start Address
00H
Read Length
00H
02H
08H
02H
01H
01H
04H
Tag Delay
14H
Checksum
50H
Terminator 
03H
124
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
After the LRP820 sends the acknowledgment, it will send the read data from
the 2 tags.
Response from LRP820
Field
Contents
Header

02H
Response Size
00H
Command Echo/Tag 1
8DH
Data from
address 0001H
05H
Data from
address 0002H
AAH
Data from
address 0003H
21H
Data from
address 0004H
44H
Checksum
59H
Terminator 
03H
Header

02H
Response Size
00H
Command Echo/Tag 2
85H
Data from
address 0001H
05H
Data from
address 0002H
AAH
Data from
address 0003H
21H
Data from
address 0004H
44H
Checksum
59H
Terminator 
03H
02H
05H
02H
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
125
ABxF Command 8E (8EH): Memory Lock All
DESCRIPTION
This command “locks” tag addresses in four byte blocks. Once bytes are
locked, they can not be unlocked.
DISCUSSION
The memory can be locked only in 4-byte blocks. The command passes a
two byte word with bits assigned to 4-byte blocks that can be locked.
Remaining bits can lock the EAS feature and the lock configuration itself.
When multiple tag-in-field is enabled (Anticollision Index is not 0), the
LRP820 will return a response when the timeout period expires. When multiple tag-in-field is disabled, the LRP820 will return a response when it locks
bytes or the timeout expires.
Attempting to write to locked bytes will return a write timeout error in the
status byte. If you write to addresses that contain both locked and
non-locked bytes, the LRP820 will return a write error in the status byte.
The configuration word formatted as shown below.
Byte
LockLSB
LockMSB
126
Bit
Description
Tag bytes 0-3
Tag bytes 4-7
Tag bytes 8-11
Tag bytes 12-15
Tag bytes 16-19
Tag bytes 20-23
Tag bytes 24-27
Tag bytes 28-31
Tag bytes 32-35
Tag bytes 36-39
10
Tag bytes 40-43
11
Tag bytes 44-47
12
Lock Configuration
13
Lock EAS feature
14
Reserved
15
Reserved
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The command is formatted as shown below.
Field
Remarks
Header

Command Size
Command length in bytes excluding the header, command size, checksum
and terminator bytes.
Command
8EH
Family Code
Tag Family ID - 00H = all tags
Anticollision index
Number of tags-in-field expected
Timeout
Timeout value given in 1 ms units
LockMSB
Bits 8-15 of the configuration word
LockLSB
Bits 0-7 of the configuration word
Checksum
Optional Checksum
Message Terminator

EXAMPLE
This example will lock bytes 0-3 on all tags-in-field with the Family ID of
02H. Two tags are found and locked.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
8EH
07H
02H
03H
Command Code
8EH
Command Echo
Family ID
02H
Number of Tags
02H
Anticollision Index
01H
Status byte
08H
07H
Checksum
64H
D0H
Terminator 
03H
Timeout
LockMSB
00H
LockLSB
01H
Checksum
8FH
Terminator 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
127
ABxF Command 94 (94H): SN Fill
DESCRIPTION
Fill an RFID tag, identified by serial number, with a one byte value over
multiple contiguous addresses.
DISCUSSION
This command is commonly used to clear an RFID tag's memory. It writes a
one byte value repetitively across a specified range of tag addresses.
The SN Fill command requires a specific serial number of the tag to be
filled. It will fill the tag with the data value byte, starting at the specified start
address for the specified number of consecutive bytes. When Fill Length is
set to 0, the LRP820 will write fill data from the start address to the end of
the tags memory. The timeout value is given in 1 msec increments and can
have a value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0,
the LRP820 will return a syntax error.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
94H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Fill Length
2-byte value for the length of the fill in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Tag Serial Number
8-byte tag serial number
Data value byte
1 byte of fill
Checksum
Optional Checksum
Terminator

128
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE
Writes 'A' (41H) to the tag specified by serial number starting at address
0005H for the following next consecutive 4 bytes. A timeout of 2 seconds
(07D0H = 2000 x 1 msec increments) is set for the completion of the configuration.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
94H
0EH
02H
03H
Command Code
94H
Command Echo
Family ID
00H
Number of Tags
01H
Anticollision Index
02H
Status byte
00H
Timeout
07H
Checksum
67H
D0H
Terminators 
03H
SN byte 1
ADH
SN byte 2
23H
SN byte 3
81H
SN byte 4
1DH
SN byte 5
C3H
SN byte 6
66H
SN byte 7
78H
SN byte 8
21H
Fill byte
41H
Checksum
13H
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
129
ABxF Command 95 (95H): SN Block Read
DESCRIPTION
Read a block of data from an RFID tag.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. The timeout value is given in 1 msec increments and can have a
value of 1EH to FFFEH (65,534 ms). When the timeout is set to 0, the
LRP820 will return a syntax error. A special error packet is sent if the timeout expires.
If the read range exceeds the last tag address, the LRP820 will return an
invalid format error message (error code 21H).
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
95H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the read in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Tag Serial Number
8-byte tag serial number
Checksum
Optional Checksum
Terminator

130
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Reads 2 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the SN Block Read. If the timeout expires before reading a tag the response
packet is: 02H 02H 00 03 FF 00 Status Chk 03H.
Command from Host
Response from LRP820, tag found
Field
Contents
Field
Contents
Header

02H
02H
02H
Header

Command Size
00H
Response Size
00H
Command Code
95H
Command Echo
95H
Family ID
AAH
05H
Anticollision Index
02H
Data from
address 0001H
Start address
00H
Data from
address 0002H
AAH
Block size
00H
11H
01H
02H
02H
03H
Checksum
B8H
Terminator 
03H
Timeout,
2 seconds
07H
SN byte 1
ADH
SN byte 2
23H
SN byte 3
81H
Field
Contents
SN byte 4
1DH
02H
SN byte 5
C3H
Header

SN byte 6
66H
Response Size
00H
SN byte 7
78H
FFH
D0H
Response from LRP820, tag not found
02H
03H
21H
Command Fail
Checksum
A3H
Ntag
00H
Terminator 
03H
Status byte
08H
Checksum
B8H
Terminator 
03H
SN byte 8
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
131
ABxF Command 96 (96H): SN Block Write
DESCRIPTION
Write a block of data to an RFID tag identified by its serial number.
DISCUSSION
The SN Block Write command is used to write segments of data to contiguous areas of tag memory. The timeout value is given in 1 msec increments
and can have a value of 1EH to FFFEH (65,534 ms). When the timeout is
set to 0, the LRP820 will return a syntax error.
The SN Block Write consists of a start address followed by the data stream
to be written to the RFID tag specified by the serial number given in the
command. If the block size exceeds the last tag address, the LRP820 will
return an invalid format error message (error code 21H).
Field
Content
Header

Packet Size
Packet length in bytes excluding the header, packet size, checksum and
terminator bytes. 0007H plus the number of data bytes
Command
96H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the write in number of bytes
Timeout
2-byte value for timeout in 1 ms units (1EH - FFFEH)
Tag Serial Number
8-byte tag serial number
Data
Data bytes to be written
Checksum
Optional Checksum
Terminator

132
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
EXAMPLE:
Writes 4 bytes of data to the tag starting at address 0000H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the SN Block Write.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header

02H
02H
Command Size
00H
Response Size
00H
15H
02H
03H
Command Code
96H
Command Echo
96H
Family ID
03H
Number of tags
01H
Anticollision Index
03H
Status byte
00H
Start address
00H
Checksum
65H
00H
Terminators 
03H
Block Size
00H
04H
Timeout,
2 seconds
07H
SN byte 1
ADH
SN byte 2
23H
SN byte 3
81H
SN byte 4
1DH
SN byte 5
C3H
SN byte 6
66H
SN byte 7
78H
SN byte 8
21H
Data to write to
address 0000H
52H
Data to write to
address 0001H
46H
Data to write to
address 0002H
49H
Data to write to
address 0003H
44H
D0H
Checksum
1EH
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
133
ABxF Command 97 (97H): SN Block Read All
DESCRIPTION
Read a block of data from all RFID tags-in-field or all those with the specified Family ID. Data will be returned with the serial number of the corresponding tag.
DISCUSSION
This command is used to read segments of data from contiguous areas of tag
memory. It is capable of handling up to 48 bytes of data transferred to the
host with one command if there is no tag family ID. The timeout value is
given in 1 msec increments and can have a value of 1EH to FFFEH (65,534
ms). When the timeout is set to 0, the LRP820 will return a syntax error.
The response to this command will contain the serial number of the responding tags preceding the data from those tags. The termination packet is transmitted when the timeout expires. Each packet will be sent to the host as soon
as it is available. The returned serial numbers can be used to read/write to
tags-in-field via the SN Block Read/Write command.
The SN Block Read All consists of Family ID and an Anticollision Index, a
start address and length, followed by a timeout value and the message terminator, , as shown below.
A special termination packet is sent when the timeout expires. If the
Anticollision Index is 0, a response is returned when the operation is successfully completed on 1 tag, or when the timeout expires. A termination
packet is not sent for successful completion if the Anticollision Index is 0.
If the read range exceeds the last tag address, the LRP820 will return an
error message in the status byte.
134
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The command is formatted as follows.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes.
Command
97H
Family ID
Tag Family ID - 00H = all tags
Anticollision Index
Number of tags expected
Start Address
2-byte value for the starting tag address
Block Size
2-byte value for the length of the read in number of bytes
Timeout
2-byte value for timeout in 1 ms units. (1EH - FFFEH)
Checksum
Optional Checksum
Terminator

NOTE:
This command can not be used with a MUX32 interface.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
135
EXAMPLE:
Reads 4 bytes of data from the tag starting at address 0001H. A timeout of 2
seconds (07D0H = 2000 x 1 msec increments) is set for the completion of
the SN Block Read All. The Tag Family byte is set to zero so all tags will be
read. Three tags respond with data.
Command from Host
Response from LRP820
Field
Contents
Field
Contents
Header

02H
Header/tag 1

02H
Command Size
00H
Response Size
00H
02H
09H
02H
0DH
Command Echo
97H
Command Code
97H
Family ID
03H
SN byte 1/tag 1
ADH
Anticollision Index
00H
SN byte 2/ tag 1
23H
Start address
00H
SN byte 3/tag 1
81H
00H
SN byte 4/tag 1
1DH
Block Size
00H
SN byte 5/tag 1
C3H
04H
SN byte 6/tag 1
66H
Timeout,
2 seconds
07H
SN byte 7/tag 1
78H
D0H
SN byte 8/tag 1
21H
Checksum
81H
Data byte 1/ tag 1
52H
Terminators 
03H
Data byte 2/tag 1
46H
Data byte 3/tag 1
49H
Data byte 4/tag 1
44H
Checksum
06H
Terminators 
03H
136
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
Header/tag 2

02H
Response Size
00H
02H
0DH
Command Code
97H
SN byte 1/tag 2
ADH
SN byte 2/ tag 2
23H
SN byte 3/tag 2
81H
SN byte 4/tag 2
1DH
SN byte 5/tag 2
C3H
SN byte 6/tag 2
66H
SN byte 7/tag 2
78H
SN byte 8/tag 2
21H
Data byte 1/ tag 2
52H
Data byte 2/tag 2
46H
Data byte 3/tag 2
49H
Data byte 4/tag 2
44H
Checksum
06H
Terminators 
03H
Header/tag 3

02H
Response Size
00H
Header

02H
Response Size
00H
Command Echo
FFH
02H
03H
Number of tags
03H
Status byte
08H
Checksum
F2H
Terminators 
03H
02H
0BH
Command Echo
97H
SN byte 1/tag 3
ADH
SN byte 2/ tag 3
23H
SN byte 3/tag 3
81H
SN byte 4/tag 3
1DH
SN byte 5/tag 3
C3H
SN byte 6/tag 3
66H
SN byte 7/tag 3
78H
SN byte 8/tag 3
21H
Data byte 1/ tag 3
52H
Data byte 2/tag 3
46H
Data byte 3/tag 3
49H
Data byte 4/tag 3
44H
Checksum
08H
Terminators 
03H
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
137
6.6 ABx
ABx ASCII
ASCII Protocol
Protocol
6.5
The ABx ASCII Protocol is based on the ABx Fast protocol. It uses the
same headers and terminator (already ASCII characters) and converts the
hex value of command and data bytes to printable ASCII (2 digit Hexadecimal notation). In another words, the hex values given in an ABx Fast command are transmitted as separate ASCII characters.
Since it is an ASCII protocol, the Xon/Xoff handshake can be used.
Command Packet Structure:
The command protocol is based on the following minimal packet structure.
The data field and the checksum may not be present depending on the command type and your checksum setting.
Field
Number of ASCII
Characters
Content
Header
 (02H, 02H)
Command Size
Packet length in bytes excluding the header, Command
size, checksum and terminator bytes.
Command Code
Command
(Data)
variable
command data/parameters
Checksum
Optional Checksum
Terminator
 (03H)
Following a successful operation, the LRP820 will respond with the following. The data field and the checksum may not be present depending on the
command and your checksum setting. If a checksum is enabled in the Configuration Menu, then it is always present for every command.
Field
Number of ASCII
Characters
Content
Header
 (02H, 02H)
Response Size
Packet length in bytes excluding the header, response size,
checksum and terminator bytes.
Command Echo
Command
(Data)
variable
response data
Checksum
Optional Checksum
Terminator
 (03H)
138
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
If the LRP820 encounters a fault it will respond with the following:
Field
Number of ASCII
Characters
Content
Header
 (02H, 02H)
Response Size
Packet length in bytes excluding the header, response size,
checksum and terminator bytes.
Error Flag
FFH
Error Code
Hex error code, see Table 11 for details
Checksum
Optional checksum
Terminator
 (03H)
Most RF operations will also require additional parameters and data that will
be included in the command stream between the command code or echo and
the terminator.
The Header and Terminator are always STX and ETX respectively. Any
other field value is in ASCII hex notation. Allowed values: '0'-'9', 'A'-'F'. Example: the value ABH (decimal 171) in ASCII protocol is transmitted as a
2-character string «AB», i.e. the 2 bytes: 41H 42H (ASCII values for 'A' and
'B'). The hex value of the hex digits given in ASCII are: '0'-'9' = 30H - 39H,
'A'-'F' = 41H-46H.
The sequence for each command is given with the response format in the
preceding section. Referring to the ABx Fast command you can structure the
ABx ASCII commands by using ASCII values for each digit of the hex values, excluding the header and terminator that are already ASCII characters.
Command/Response Size
The ABx ASCII requires the length of the packet be included in the command. All parameters and data between the Command Size and the terminator or checksum byte must be accounted for in the packet size word. This
includes all command codes and parameters such as field definition for
Block Read/Writes. The packet size remains the same with, or without the
checksum.
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
139
Checksum
The optional checksum must be enabled from the operating mode menu to
be available. The checksum is calculated by adding all the byte values (not
the ASCII translation values) in the packet (less the values in the header,
checksum if present, and terminator), discarding byte overflow and subtracting the byte sum from FFH.
Example ASCII Command
Fill Tag
This command fills the specified number of cells from the specified start address with the specified value. Block size = 0 means filling to the end of the
memory. The command will take the same form as the ABx Fast command.
Field
Content
Header

Command Size
Packet length in bytes excluding the header, command size, checksum and
terminator bytes. Given as four ASCII character value. 0008H for this command
Command
<30H><34H> (04)
Start Address
4 ASCII character value for the starting tag address
Fill Length
4 ASCII character value for the length of the fill in number of bytes
Timeout
4 ASCII character value for timeout in 1 ms units. (1EH - FFFEH)
Data value byte
2 ASCII character value for 1 byte of fill
Checksum
2 ASCII character value for Optional Checksum
Terminator

140
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
The ASCII character string for a fill of 32 bytes, from address 0 with 55H
value, timeout 5 sec., follows.
Response from LRP820
Command from Host
Field
ASCII
Hex
Value
ASCII
String
Field
ASCII
Hex
Value
ASCII
String
Header

02H
STX
02H
STX
02H
STX
Header

02H
STX
Command Size
30H
Response Size
30H
30H
30H
30H
31H
38H
30H
Command Echo
30H
34H
Checksum
46H
41H
03H
ETX
Command
Start Address
Fill Length
Timeout Value
Data Byte Value
30H
34H
30H
30H
30H
30H
30H
30H
32H
30H
31H
33H
38H
38H
35H
35H
Checksum
45H
33H
Terminators 
03H
ETX
Terminators 
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
141
A APPENDIX: SPECIFICATIONS
Table 10 LRP820 Specifications
Electrical
Supply Voltage
Power Consumption
18-30 Vdc
31W (1.3 A @ 24Vdc)
Communication
RFID Interface
Bus Interface
COM1
COM2
Inputs
Output
LRP-Series Passive RFID System
MUX32
RS232/RS422/MUX32
RS232
Four industrial-level inputs, 4.5-30 Vdc (25mA max)
Four industrial-level outputs, 30 Vdc (500 mA max)
Mechanical Specifications
Dimensions (L x W x H)
Weight
Enclosure
Environmental
Operating Temperature
Storage Temperature
Humidity
Shock Resistance
Vibration Resistance
Protection Class
8.66 x 4.72 x 3.83 inches
(220 x 120 x 97 cm)
3.5 lb. (1.59 kg)
Cast Aluminum Alloy
-4 to 120 degrees F
(-40 to 49 degrees C)
-40 to 185 degrees F
(-40 to 85 degrees C)
95% non-condensing
IEC 68-2-27 test EA 30g;
11 msec; 3 shocks each axis
IEC 68-2-6 test FC 1.5 mm;
10 to 55 Hz; 2 hours each axis
NEMA 4 (IP66)
NOTE: Specifications are subject to change without notice.
142
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
B APPENDIX: MODELS
Table 12 — Models and Accessories
Available Models
Part Number
Description
LRP820-10
Long range, passive controller, RS232, RS422 and MUX32/RS485 communications, 4 digital inputs and 4 digital outputs, tunnel antenna
LRP820-04
Long range, passive controller, RS232, RS422 and MUX32/RS485 communications, 4 digital inputs and 4 digital outputs, conveyor-mount antenna
LRP820-08
Long range, passive controller, RS232, RS422 and MUX32/RS485 communications, 4 digital inputs and 4 digital outputs, plate antenna, 12 x 14"
Accessories
Part Number
Description
00-1122
Connector Kit, all five mating connectors for wiring the LRP820
46-1268
Mating Connector, MUX32 connector, 8 pin metal circular
46-1270
Mating Connector, Power connector, 3 socket metal circular
46-1456
Mating Connector, COM1/COM2 connector, 14 pin metal circular
46-1458
Mating Connector, Input connector, 12 socket metal circular
46-1460
Mating Connector, Output connector, 12 pin metal circular
46-5119
Connector covers, shell size 12, fits MUX32 and COM1/COM2 connectors
46-5120
Connector covers, shell size 14, fits Input and Output connectors
LRP125
Passive read/write tag, 25 mm round, 48 bytes memory
LRP125HT
Passive read/write tag, 25 mm round, survives 200° temperatures, 48 bytes
memory
LRP250
Passive read/write tag, 50 mm square, 48 bytes memory
LRP250HT
Passive read/write tag, 50 mm square, survives 200° temperatures, 48 bytes
memory
LRP250HT-FLX
Passive read/write tag, 50 mm square, survives 200° temperatures, flexible
with high temperature adhesive backing, 48 bytes memory
LRP-L5555
Passive read/write tag, 55 mm square, thermal transfer with adhesive backing,
48 bytes memory
LRP-L2666
Passive read/write tag, 26 x 66 mm, thermal transfer with adhesive backing,
48 bytes memory
LRP-L4982
Passive read/write tag, 49 x 82 mm, thermal transfer with adhesive backing,
48 bytes memory
LRP-L90140
Passive read/write tag, 90 x 140 mm, thermal transfer with adhesive backing,
48 bytes memory
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
143
Table 12 — Models and Accessories (cont)
Accessories
Part Number
Description
LRP-P125
Passive read/write tag, 25 mm, PCB, 48 bytes memory
LRP-P3858
Passive read/write tag, 38 x 38 mm, PCB, 48 bytes memory
LRP-P5050
Passive read/write tag, 50 x 50 mm, PCB, 48 bytes memory
144
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
C APPENDIX: ASCII CHART
Decimal
Hex
Character
Decimal
Hex
Character
000
00
NUL
032
20
(space)
001
01
SOH
033
21
002
02
STX
034
22
''
003
03
ETX
035
23
004
04
EOT
036
24
005
05
ENQ
037
25
006
06
ACT
038
26
007
07
BEL
039
27
008
08
BS
040
28
009
09
HT
041
29
010
0A
LF
042
2A
011
0B
VT
043
2B
++
012
0C
FF
044
2C
013
0D
CR
045
2D
014
0E
SO
046
2E
015
0F
SI
047
2F
016
10
DLE
048
30
017
11
DC1
049
31
018
12
DC2
050
32
019
13
DC3
051
33
020
14
DC4
052
34
021
15
NAK
053
35
022
16
SYN
054
36
023
17
ETB
055
37
024
18
CAN
056
38
025
19
EM
057
39
026
1A
SUB
058
3A
027
1B
ESC
059
3B
028
1C
FS
060
3C
029
1D
GS
061
3D
030
1E
RS
062
3E
031
1F
US
063
3F
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer
145
Decimal
Hex
Character
Decimal
Hex
Character
064
40
096
60
065
41
097
61
066
42
098
62
067
43
099
63
068
44
100
64
069
45
101
65
070
46
102
66
071
47
103
67
072
48
104
68
073
49
105
69
074
4A
106
6A
075
4B
107
6B
076
4C
108
6C
077
4D
109
6D
078
4E
110
6E
079
4F
111
6F
080
50
112
70
081
51
113
71
082
52
114
72
083
53
115
73
084
54
116
74
085
55
117
75
086
56
118
76
087
57
119
77
088
58
120
78
089
59
121
79
090
5A
122
7A
091
5B
123
7B
092
5C
124
7C
093
5D
125
7D
094
5E
^^
126
7E
095
5F
—
127
7F
DEL
146
Copyright © 2000 Escort Memory Systems
LRP820-Series Long-Range Passive Reader/Writer

---

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