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User Manual Lrp820

OPERATOR'S MANUAL

LRP820-Series

Long-Range Passive

Reader/Writers

Manual Revision 3, July, '00

Publication #17-1269

ii LRP820-Series Long-Range Passive Reader/Writer

Escort Memory Systems Warranty

Escort Memory Systems warrants that all products of its own manufacture conform to Es-

cort 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 Sys-

tems 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 de-

fect 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 here-

under. 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 im-

plied 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, ne-

glect, unauthorized repair or installation are not covered by warranty. Escort Memory Sys-

tems 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 re-

served. The information in this manual has been carefully checked and is believed to be accu-

rate; 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

LRP820-Series Long-Range Passive Reader/Writer iii

TABLE OF CONTENTS

1GETTING STARTED 1

1.1 Introduction ....................1

1.2 Unpacking and Inspection ..............3

2MECHANICAL SPECIFICATIONS 4

2.1 Dimensions ....................4

2.2 RF Range and Orientation ..............7

2.3 Mounting Guidelines................12

Guidelines ....................13

3POWER AND ELECTRICAL INTERFACE 14

3.1 Connector Panel .................14

3.2 Power Connector .................15

3.3 COM1/COM2 Connector .............15

3.4 MUX32 Connector ................16

Serial Communications Cabling ...........16

3.5 Input Connector..................17

3.6 Output Connector .................17

3.7 Digital I/O Wiring.................18

3.8 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

3.9 LED Indicators ..................27

4SERIAL AND BUS COMMUNICATIONS 29

4.1 Serial Interfaces..................29

Digital Board DIP Switch .............30

4.2 Bus Interfaces...................32

MUX32 Interface Board DIP Switch ........33

5MENU CONFIGURATION 34

5.1 How to Enter Menu Configuration .........34

5.2 Set-up Operating Parameters ............35

Set COM1 Parameters ...............36

iv LRP820-Series Long-Range Passive Reader/Writer

Set COM2 Parameters ...............36

Set Operating Mode ................36

Set RF Communication ..............38

Restore Factory Defaults ..............38

Return to Main Menu ...............39

5.3 Download New Program ..............39

5.4 Downloading DSP Firmware ............39

5.5 Exit to Operating Mode ..............40

6 RFID INTERFACE 41

6.1 Introduction ...................41

Command Timeout . . . .............41

MUX32 and Anticollision Limitations ........43

6.2 ABx Error Codes .................44

Non-Anticollision Error Codes ............44

ABx Standard...................44

ABx Fast.....................45

Anticollision Status Byte ..............46

6.3 Anticollision Commands ..............47

Family Interrogation . . . .............47

Family ID ....................47

Anticollision Index . . . .............48

6.4 ABx Standard Protocol ..............49

ABxS Command 4 (04H): Fill Tag .........49

ABxS Command 5 (05H): Block Read ........51

ABxS Command 6 (06H): Block Write........53

ABxS Command 7 (07H): Read Tag Serial Number . . 55

ABxS Command 8 (08H): Tag Search ........56

ABxS Command D (0DH): Continuous Block Read . . 57

ABxS Command 10 (10H): Set Output ........60

ABxS Command 11 (11H): Input Status .......62

ABxS Command 84 (84H): Fill Tag All .......64

ABxS Command 85 (85H): Block Read All......66

ABxS Command 86 (86H): Block Write All .....68

ABxS Command 87 (87H): Read Tag SN All .....70

ABxS Command 88 (88H): Tag Search All ......72

ABxS Command 89 (89H): EAS Set/Reset All ....73

ABxS Command 8A (8AH): EAS Start/Stop .....75

ABxS Command 8D (8DH): Continuous Read All. . . 77

ABxS Command 8E (8EH): Memory Lock All ....79

LRP820-Series Long-Range Passive Reader/Writer v

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

6.5 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

6.6 ABx ASCII Protocol ...............138

Command Packet Structure: ............138

Command/Response Size .............139

Checksum ....................140

Example ASCII Command ............140

AAPPENDIX: SPECIFICATIONS 142

BAPPENDIX: MODELS 143

CAPPENDIX: ASCII CHART 144

vi LRP-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:

nReorient or relocate the receiving antenna.

nIncrease the separation between the equipment and the re-

ceiver.

nConnect the equipment into an outlet on a circuit different

from that to which the receiver is connected.

nConsult the dealer or an experienced radio/TV technician for

help.

CAUTION

Changes or modifications not expressly approved by Escort Memory Sys-

tems could void the user’s authority to operate the equipment.

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 inter-

faces, and ancillary equipment. Tags can be attached to a product or its car-

rier 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 stand-

ing still.

Escort Memory Systems' LRP-Series long range passive RFID system is the

latest in our line of high performance, industrial RFID equipment. The pas-

sive 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 infor-

mation.

The LRP820 is specifically designed to work with LRP-Series passive tags,

which provide 48 bytes of reprogrammable memory.

LRP820-Series Long-Range Passive Reader/Writer 1

The LRP820 supports the multidrop protocol MUX32. The LRP820 is

encased in a NEMA4 enclosure and features two serial ports, 4 opto-

isolated 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.

2LRP820-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 dam-

aged, notify your distributor immediately. The LRP820 is delivered with the

following components:

nLRP820 (-04, -08) Reader/Writer

nLRP820 to Antenna cable

nLRP820 Operator's Manual

The following components are required for configuring a complete system:

nLRP-Series Passive Read/Write Tags

nUser supplied LRP820-to-host cable

nMUX32 host

n18 - 30 Vdc, 36 W (1.5 A @ 24 Vdc) power supply

nMating connectors. See Appendix B for more information

LRP820-Series Long-Range Passive Reader/Writer 3

2 MECHANICAL SPECIFICATIONS

2.1 Dimensions

Figure 1 gives the dimensions for the LRP820. Figures 2-3 show the dimen-

sions of the 04 and 08 remote antennas.

4LRP820-Series Long-Range Passive Reader/Writer

Figure 1 — LRP820 Dimensions

inches

LRP820-Series Long-Range Passive Reader/Writer 5

Figure 2 — LRP-04 Conveyor-Mount Antenna

inches

6LRP820-Series Long-Range Passive Reader/Writer

Figure 3 — LRP-08 Antenna Dimensions

inches

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 typ-

ical and guaranteed ranges of the LRP series tags.

LRP820-Series Long-Range Passive Reader/Writer 7

Figure 4 — LRP-08 to Tag Orientation

8LRP820-Series Long-Range Passive Reader/Writer

Figure 5 — Side View of RF Field, LRP-04 Antenna, 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 be-

tween 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.

Table 1 — Antenna to Tag Ranges, LRP-04 Antenna with Metal*

LRP820-Series Long-Range Passive Reader/Writer 9

Figure 6 — End View of RF Field, LRP-04 Antenna, Metal

10 LRP820-Series Long-Range Passive Reader/Writer

Figure 7 — End View of RF Field, LRP-08 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.

Table 2 — Antenna to Tag Ranges, LRP-04 Antenna, No Metal*

LRP820-Series Long-Range Passive Reader/Writer 11

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.

Table 3 — Antenna to Tag Ranges, LRP-08 Antenna, No Metal

Figure 8 — Side View of RF Field, LRP-08 Antenna, No Metal

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. Sur-

rounding 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 dis-

tance on the side.

12 LRP820-Series Long-Range Passive Reader/Writer

Figure 9 — LRP820 Mounting Holes

inches

Special mounting instructions must be followed to get optimal read/write

performance from the LRP820-08 antenna. Mount the antenna with a mini-

mum 5.90" (150mm) spacing from any metal to the back or sides of the an-

tenna, as shown in Figure 10.

Guidelines

nIsolate the LRP820 and antenna from electromagnetic

radiation.

nAvoid surrounding LRP820 and remote antenna with metal.

nMaintain at least 2 meters minimum spacing between adjacent

LRP820s or antennas.

nStay within the guaranteed range for the tag to be used.

nConform with EIA RS232, RS422 and RS485 standards.

LRP820-Series Long-Range Passive Reader/Writer 13

Figure 10 — Antenna Mounting, -08

inches

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.

14 LRP820-Series Long-Range Passive Reader/Writer

Figure 11 — Connector Panel

3.2 Power Connector

Figure 12 shows the power connector pin designations.

3.3 COM1/COM2 Connector

Figure 13 shows the connector pin designations for the COM port connec-

tions.

LRP820-Series Long-Range Passive Reader/Writer 15

Figure 12 — Power Connector

Figure 13 — COM1/COM2 Connector

3.4 MUX32 Connector

Figure 14 shows the connections for the MUX32/RS485 connector.

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 LRP820-Series Long-Range Passive Reader/Writer

Figure 14 — MUX32 Connector Pinouts

3.5 Input Connector

Figure 15 shows the Input Connector pin designations.

3.6 Output Connector

Figure 16 shows the Output Connector pin designations.

LRP820-Series Long-Range Passive Reader/Writer 17

Figure 16 — Output Connector Pinouts

Figure 15 — Input Connector Pinouts

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 config-

ured 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 in-

rush 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 LRP820-Series Long-Range Passive Reader/Writer

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 shows a switch connected on the low side with the high side con-

nected to the positive supply. This also requires a high quality sealed contact.

LRP820-Series Long-Range Passive Reader/Writer 19

Figure 17 — Input from Sourcing Contact

Figure 18 — Input from Sinking Contact

Figure 19 shows an Open Collector NPN output from a photosensor switch-

ing to ground. It can be wired as a sinking or low-side contact.

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 LRP820-Series Long-Range Passive Reader/Writer

Figure 20 — Input from PNP Sensor

Figure 19 — Input from NPN Sensor

Figure 21 shows a relay connected as a current sourcing "Contact." The re-

lay is grounded and the +OUT terminal goes to the positive supply. The di-

ode 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 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.

LRP820-Series Long-Range Passive Reader/Writer 21

Figure 22 — Sinking Output "Contact"

Figure 21 — Sourcing Output "Contact"

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 pro-

vide 20 mA LED current when run from 24 Vdc.

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 LRP820-Series Long-Range Passive Reader/Writer

Figure 24 — Output to TTL or CMOS

Figure 23 — Sinking Output LED Driver

3.8 Power Requirement

The LRP820 power supply requirements are:

n18 to 30Vdc

n31Watts maximum consumption

The maximum current consumption at 24Vdc is 1.3 A.

Power Options

There are three options for powering the LRP820:

nPowered 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.

nPowered via the external power connector

This is how you must power the LRP820 if you are not connecting

the LRP820 to a MUX32 network.

nPowered 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 spec-

ifications 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 loca-

tions. The following sections describe how to make these changes.

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 net-

work. 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 se-

cure the cover.

2. Refer to Figure 25 and then move the power cable, labeled assem-

bly 10-3110, from connector J7 to J9.

3. The MUX32 cable, labeled assembly 10-3111, must then ex-

change places with the power cable, moving from J9 to J7.

Figure 25 — Power Cable Connectors J7 and J9

24 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.

LRP820-Series Long-Range Passive Reader/Writer 25

Figure 26 — Power Jumper Position for External Powering Only

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 se-

cure the cover.

2. Refer to Figure 25 and then move the power cable, labeled assem-

bly 10-3110, from connector J7 to J9.

3. The MUX32 cable, labeled assembly 10-3111, must then ex-

change 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 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.

LRP820-Series Long-Range Passive Reader/Writer 27

Figure 27 — LRP820 Front with LEDs

Table 4 shows these LEDs and their meaning.

Additional LED behavior may be observed during certain commands and

conditions. This behavior will be indicated as appropriate elsewhere in this

manual.

28 LRP820-Series Long-Range Passive Reader/Writer

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-1.5sec. flash

ERROR +

CONFIG

green/red 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

Table 4 — LED Indicators

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 down-

loading 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:

nBaud rate: 1200, 2400, 4800, 9600, 19200, 38400 bps

nData: 7, 8

nParity: Even, Odd, None

nHandshake: None, Xon/Xoff

The specification for the COM2 interface follows:

nBaud rate: 1200, 2400, 4800, 9600, 19200 bps

nData: 7, 8

nParity: Even, Odd, None

nHandshake: None, Xon/Xoff

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.

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 LRP820-Series Long-Range Passive Reader/Writer

Figure 28 — Digital Board with DIP Switch

NOTE:

DIP switch 4 must be in the default ON position for the MUX32 interface to

function.

LRP820-Series Long-Range Passive Reader/Writer 31

Baud rate Interface

Download/

Restore

Defaults

SW 2 SW 3 SW 4 SW 5 Settings

9600

ON 19200

ON 38400

ON ON Set from Configuration Menu

RS232

ON RS422

ON MUX32

ON ON Reserved

Disabled

ON Enabled Download/ Restore defaults

Table 5 Main Board DIP Switch Settings

4.2 Bus Interfaces

The COM1 serial port, beside the RS232 or RS422 options, can be config-

ured as a MUX32 interface.

The following MUX32 bus parameters are set by the DIP switches found on

the Interface Board.

nBus Rate: 9600, 346Kbps

nMUX32 Slave Address

32 LRP820-Series Long-Range Passive Reader/Writer

Figure 29 — MUX32 Interface Board DIP Switch

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.

LRP820-Series Long-Range Passive Reader/Writer 33

MUX32 Address Reserved Bus Rate

SW 1 SW 2 SW 3 SW 4 SW 5 SW 6 SW 7 SW 8 Setting

Switches 6 and

7 are not used

- leave in the

OFF

position

MUX Addr. 0

ON MUX Addr. 1

ON MUX Addr. 2

ON ON MUX Addr. 3

ON MUX Addr. 4

ON ON MUX Addr. 5

ON ON MUX Addr. 6

ON ON ON MUX Addr. 7

ON MUX Addr. 8

ON ON MUX Addr. 9

ON ON MUX Addr. 10

ON ON ON MUX Addr. 11

ON ON MUX Addr. 12

ON ON ON MUX Addr. 13

ON ON ON MUX Addr. 14

ON ON ON ON MUX Addr. 15

ON MUX Addr. 16

ON ON MUX Addr. 17

ON ON MUX Addr. 18

ON ON ON MUX Addr. 19

ON ON MUX Addr. 20

ON ON ON MUX Addr. 21

ON ON ON MUX Addr. 22

ON ON ON ON MUX Addr. 23

ON ON MUX Addr. 24

ON ON ON MUX Addr. 25

ON ON ON MUX Addr. 26

ON ON ON ON MUX Addr. 27

ON ON ON MUX Addr. 28

ON ON ON ON MUX Addr. 29

ON ON ON ON MUX Addr. 30

ON ON ON ON ON MUX Addr. 31

OFF 9600 bps

ON 346K bps

Table 6 — MUX32 DIP Switch Settings

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 Sys-

tems’ Web site at www.ems-rfid.com.

LRP820 Standard PC Serial Port

COM2 Pin Number Signal Name DB9 Pin Number Signal Name

RTX2 RX

PRX3TX

M GND 5 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 8

Stop bits 1

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 val-

ues.

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 infor-

mation on the serial interface.

34 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 initial-

ization. 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 ver-

sion.

******************************************************

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.

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 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 param-

eters.

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.

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 fol-

lowing the starting tag address. Entering a read length of 0 will disable Con-

tinuous 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 strip-

ping the command protocol from the data and adding a terminator to sepa-

rate 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 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 re-

set. 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 informa-

tion 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. Be-

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 pa-

rameters 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 LRP820-Series Long-Range Passive Reader/Writer

6RFID 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 com-

patible 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 avail-

able 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 time-

out 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 exe-

cute 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.

LRP820-Series Long-Range Passive Reader/Writer 41

NOTE:

The delay between the characters of the command packet the LRP820 can-

not be longer than 200 ms.

42 LRP820-Series Long-Range Passive Reader/Writer

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.

Table 7 - ABx Command Set Listing

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 communica-

tions.

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.

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.

A Block Write fail error message would appear as: AAFF 0006 FFFFH.

44 LRP820-Series Long-Range Passive Reader/Writer

MSB LSB Remarks

AAH FFH Command Error

00H XXH Error Code

FFH FFH Message Terminator

Error Code Description

04H Fill Operation has failed

05H Block Read has failed

06H Block Write has failed

08H Search Tag Operation failed

21H Input Command does not match pre-defined format (syntax error)

Table 8 — Non-Anticollision Error Codes

ABx Fast

The format of the error response is shown below.

A Block Write fail error message would appear as: 0202 0002 FF06 F803H.

ABx ASCII

The format of the error response is shown below.

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: <STX><STX>0002FF06F8<ETX>.

In hexadecimal the commands appears as:

02H 02H 30H 30H 30H 32H 46H 46H 30H 36H 46H 38H 03H

LRP820-Series Long-Range Passive Reader/Writer 45

Field Bytes Contents

Header

02H

Response Size 00H

02H

Error Flag FFH

Error Code XXH

Checksum XXH

Terminators <ETX> 03H

Field # of ASCII

characters

Contents

Header

<STX><STX> 2

<STX> 02H

Response Size 4 Packet length in bytes excluding the header, response size,

checksum and terminator bytes

Error Flag 2 FFH

Error Code 2 XXH - see Table 7 for details

Checksum 2 XXH - optional checksum

Terminators <ETX> 1 <ETX> 03H

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 execu-

tion. The format of the response is in all other ways, the same as a successful

response.

The STATUS byte is defined as follows:

76543210

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 oc-

curred during the command execution. Multiple conditions can occur in the

same command.

Antenna There is an error at the antenna

Failure

R/W error Error during the tag memory access

Collision 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 Internal error in low-level firmware

(contact Escort Memory Systems technical assistance)

Timeout Timeout expired

Verify Error 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 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 multi-

ple 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.

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 Max number of tags

0 1 (*)

1 2-4

2 4-8

3 8-16

4 16-32

5 32-64

6 64-128

7 >128

(*) anticollision disabled

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 ex-

pired. If the command has the Anticollision Index set to 0, then a response

will be returned after the first successful operation.

48 LRP820-Series Long-Range Passive Reader/Writer

The Anticollision Commands return a successful response whenever the op-

eration 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 ex-

pressed in 2 byte words, in order to be compatible with the HMS commands

and to allow future developments.

6.3 ABx Standard Protocol

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

LRP820-Series Long-Range Passive Reader/Writer 49

6.4 ABx Standard Protocol

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.

50 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 04H Perform Command 4

00H 05H Start Address = 0005H

00H 0AH Fill Length= 10 bytes

(000AH)

07H D0H Timeout value

00H 41H Data Value Byte = 41H

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 04H Command echo

FFH FFH Message Terminator

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 ex-

ceeds the last tag address, the LRP820 will return error message 21H, in-

valid 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

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.

52 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 05H Perform Command 5

00H 01H Start Address = 0001H

00H 08H Read Block Length = 8 bytes

(0008H)

07H D0H Timeout Value

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 05H Command echo

00H 52H Read Data1=52H

00H 46H Read Data2=46H

00H 49H Read Data3=49H

00H 44H Read Data4=44H

00H 20H Read Data5=20H

00H 54H Read Data6=54H

00H 61H Read Data7=61H

00H 67H Read Data8=67H

FFH FFH Message Terminator

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 incre-

ments and can have a value of 1EH to FFFEH (65,534 ms). When the time-

out 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

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.

54 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 06H Perform Command 6

00H 20H Start Address = 0020H

00H 04H Write Length = 4 bytes

07H D0H Timeout Value

00H 52H Write Data1=52H

00H 46H Write Data2=46H

00H 49H Write Data3=49H

00H 44H Write Data4=44H

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 06H Command echo

FFH FFH Message Terminator

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.

LRP820-Series Long-Range Passive Reader/Writer 55

Command from Host

MSB LSB Remarks

AAH 07H Perform Command 7

07H D0H Timeout

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 07H Command Echo

00H 1EH First SN byte

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

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.

56 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 08H Perform Command 8

07H D0H Timeout Value

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 08H Command echo

FFH FFH Message Terminator

ABxS Command D (0DH): Continuous Block Read

DESCRIPTION

When in Continuous Block Read mode, the LRP820 sends block reads con-

tinuously 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 Identi-

cal 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 param-

eters: 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 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

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.

The LRP820 will first return an acknowledgment of the command followed

by a response containing read data when a tag enters the antenna field.

58 LRP820-Series Long-Range Passive Reader/Writer

Response from LRP820

MSB LSB Remarks

AAH 0DH Command echo

FFH FFH Message Terminator

Command from Host

MSB LSB Remarks

AAH 0DH Perform Command D

00H 01H Start address

00H 08H Read 8 bytes

00H 02H 2 second delay

FFH FFH Message Terminator

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

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.

LRP820-Series Long-Range Passive Reader/Writer 59

Command from Host

MSB LSB Remarks

AAH 0DH Perform Command D

00H 01H Start address

00H 00H Read 0 bytes/end mode

00H 02H 2 second delay

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 0DH Command echo

FFH FFH Message Terminator

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=ONand0=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.

Field Remarks

Command Command number in hex preceded by AAH

Output Pattern Hex value for the bit output settings

Message Terminator FFFFH

60 LRP820-Series Long-Range Passive Reader/Writer

MSB LSB Remarks LSB Bit 3

Output D

LSB Bit 2

Output C

LSB Bit 1

Output B

LSB Bit 0

Output A

00H 00H Reset A, B, C, D 0000

00H 01H Set Output A - Reset B, C, D 0001

00H 02H Set Output B - Reset A, C, D 0010

00H 03H Set Output A, B - Reset C, D 0011

00H 04H Set Output C - Reset A, B, D 0100

00H 05H Set Output A, C - Reset B, D 0101

00H 06H Set Output B, C - Reset A, D 0110

00H 07H Set Output A, B, C - Reset D 0111

00H 08H Set Output D - Reset A, B, C 1000

00H 09H Set Output A, D - Reset B, C 1001

00H 0AH Set Output B, D - Reset A, C 1010

00H 0BH Set Output A, B, D - Reset C 1011

00H 0CH Set Output C, D - Reset A, B 1100

00H 0DH Set Output A, C, D - Reset B 1101

00H 0EH Set Output B, C, D - Reset A 1110

00H 0FH Set Output A, B, C, D 1111

EXAMPLE

The following example sets Output B only and resets A, C, and D.

LRP820-Series Long-Range Passive Reader/Writer 61

Command from Host

MSB LSB Remarks

AAH 10H Perform Command 10

00H 02H Set Output B

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 10H Command echo

FFH FFH Message Terminator

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=ONand0=OFF.

The following chart shows the hex values for all input conditions that can be

returned in the second word of the response.

Field Remarks

Command Command number in hex preceded by AAH

Message Terminator FFFFH

62 LRP820-Series Long-Range Passive Reader/Writer

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 0000

00H 01H Input A, ON - B, C, D, OFF 0001

00H 02H Input B, ON - A, C, D, OFF 0010

00H 03H Input A, B, ON - C, D, OFF 0011

00H 04H Input C, ON - A, B, D, OFF 0100

00H 05H Input A, C, ON - B, D, OFF 0101

00H 06H Input B, C, ON - A, D, OFF 0110

00H 07H Input A, B, C, ON - D, OFF 0111

00H 08H Input D, ON - A, B, C, OFF 1000

00H 09H Input A, D, ON - B, C, OFF 1001

00H 0AH Input B, D, ON - A, C, OFF 1010

00H 0BH Input A, B, D, ON - C, OFF 1011

00H 0CH Input C, D, ON - A, B, OFF 1100

00H 0DH Input A, C, D, ON - B, OFF 1101

00H 0EH Input B, C, D, ON - A, OFF 1110

00H 0FH Input A, B, C, D, ON 1111

EXAMPLE

The following example shows only Input B is ON.

LRP820-Series Long-Range Passive Reader/Writer 63

Command from Host

MSB LSB Remarks

AAH 11H Perform Command 11

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 11H Command echo

00H 02H Input B ON

FFH FFH Message Terminator

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 en-

abled), 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 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.

LRP820-Series Long-Range Passive Reader/Writer 65

Command from Host

MSB LSB Remarks

AAH 84H Perform Command 84

01H 02H Tag Family 01/ Index 2

00H 05H Start Address

00H 28H Fill Length

07H D0H Timeout

00H 41H Fill byte

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 84H Command Echo

04H 08H Ntag/Status

FFH FFH Message Terminator

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 termi-

nator, 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 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.

LRP820-Series Long-Range Passive Reader/Writer 67

Command from Host

MSB LSB Remarks

AAH 85H Perform Command 85

00H 02H Tag Family 00/ Index 2

00H 01H Start Address

00H 04H Read Length

07H D0H Timeout

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 85H 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 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

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 incre-

ments and can have a value of 1EH to FFFEH (65,534 ms). When the time-

out 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 mes-

sage 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 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.

LRP820-Series Long-Range Passive Reader/Writer 69

Command from Host

MSB LSB Remarks

AAH 86H Perform Command 86

02H 02H Tag Family/ Index 2

00H 01H Start Address

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

Response from LRP820

MSB LSB Remarks

AAH 86H Command Echo

04H 08H Ntags/Status

FFH FFH Message Terminator

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 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.

LRP820-Series Long-Range Passive Reader/Writer 71

Command from Host

MSB LSB Remarks

AAH 87H Perform Command 87

01H 01H Family ID/ Index 1

07H D0H Timeout

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 87H Command Echo

00H 1EH First SN byte

00H 6EH Second SN byte

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

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 ex-

pired 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.

72 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 88H Perform Command 88

00H 01H Family ID/Anticollision Index 1

07H D0H 2 second Timeout

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 88H Command Echo

01H 00H Ntags/Status

FFH FFH Message Terminator

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 mul-

tiple 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

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 com-

mand is issued, 5 tags with Family ID 09H are found and enabled for EAS.

74 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 89H Perform Command 89

09H 02H Family ID/Anticollision Index 2

07H D0H Timeout

00H 01H Enable EAS

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 89H Command Echo

05H 08H Ntags/Status

FFH FFH Message Terminator

ABxS Command 8A (8AH): EAS Start/Stop

DESCRIPTION

If are using the EAS feature in your application, the EAS Start/Stop com-

mand 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 com-

mand 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 trig-

ger 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 fol-

lowing 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

LRP820-Series Long-Range Passive Reader/Writer 75

EXAMPLE

This example starts EAS mode. Three responses follow. The first is a com-

mand 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.

When an EAS-enabled tag enters the antennas’ field, the LRP820 responds

with an EAS tag-in-field response.

When all EAS-enabled tags have left the field, the LRP820 will send the fol-

lowing response.

76 LRP820-Series Long-Range Passive Reader/Writer

Tags-in-Field Response from LRP820

MSB LSB Remarks

AAH 8AH Command Echo

01H 00H Ntag/Status

FFH FFH Message Terminator

EAS Tags Left Field

Response from LRP820

MSB LSB Remarks

AAH 8AH Command Echo

00H 00H Ntag/Status

FFH FFH Message Terminator

Command from Host

MSB LSB Remarks

AAH 8AH Perform Command 8A

00H 00H Family ID/null byte

00H 01H Start/Stop

FFH FFH Message Terminator

ACT Response from LRP820

MSB LSB Remarks

AAH 8AH Command Echo

FFH 00H Ntag/Status

FFH FFH Message Terminator

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.

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.

After the LRP820 sends the acknowledgment, it will send the read data from

the 3 tags.

78 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 8DH Perform Command 8D

00H 02H Tag Family 00/ Index 2

00H 01H Start Address

00H 04H Read Length

00H 14H Tag Delay

FFH FFH Message Terminator

ACK Response from LRP820

MSB LSB Remarks

AAH 8DH Command Echo

FFH FFH Message Terminator

Data response from LRP820

MSB LSB Remarks

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

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. Re-

maining 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 mul-

tiple 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 Bit Description

LockLSB 0 Tag bytes 0-3

1 Tag bytes 4-7

2 Tag bytes 8-11

3 Tag bytes 12-15

4 Tag bytes 16-19

5 Tag bytes 20-23

6 Tag bytes 24-27

7 Tag bytes 28-31

LockMSB 8 Tag bytes 32-35

9 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

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.

80 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 8EH Perform Command 8E

02H 01H Family ID/anticollision Index

07H D0H 2 second timeout

00H 01H Lock Configuration

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 8EH Command Echo

02H 08H Ntag/Status

FFH FFH Message Terminator

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

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 follow-

ing 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.

82 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 94H Perform Command 94

00H 01H Family ID/ Index 1

00H 05H Start Address

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

Response from Host

MSB LSB Remarks

AAH 94H Command Echo

01H 00H Ntag/Status

FFH FFH Message Terminator

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 time-

out 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

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 incre-

ments) 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.

84 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 95H Perform Command 95

00H 02H Tag Family 00/ Index 2

00H 01H Start Address

00H 04H Read Length

07H D0H Timeout

00H ABH SN byte 1

00H 02H SN byte 2

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

Response from LRP820

MSB LSB Remarks

AAH 95H Command Echo

00H 30H Data byte 1

00H 31H Data byte 2

00H 32H Data byte 3

00H 33H Data byte 4

01H 00H Ntag/Status

FFH FFH Message Terminator

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 incre-

ments and can have a value of 1EH to FFFEH (65,534 ms). When the time-

out 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

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.

86 LRP820-Series Long-Range Passive Reader/Writer

Response from LRP820

MSB LSB Remarks

AAH 96H Command Echo

01H 00H Ntags/Status

FFH FFH Message Terminator

Command from Host

MSB LSB Remarks

AAH 96H Perform Command 96

02H 02H Tag Family 02/ Index 2

00H 01H Start Address

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

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 respond-

ing tags preceding the data from those tags. The termination packet is trans-

mitted 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 suc-

cessfully 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.

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.

88 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

MSB LSB Remarks

AAH 97H Perform Command 97

00H 02H Tag Family 00/ Index 2

00H 01H Start Address

00H 02H Read Length

07H D0H Timeout

FFH FFH Message Terminator

Response from LRP820

MSB LSB Remarks

AAH 97H Command Echo/Tag 1

00H 10H SN byte 1/Tag 1

00H 43H SN byte 2/Tag 1

00H 6CH SN byte 3/Tag 1

00H 73H SN byte 4/Tag 1

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

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

6.4 ABx Fast Protocol

The difference from the standard ABx are:

nThe command/response packet contains the packet size

nYou can include a checksum in the command

nThe headers and terminator are ASCII characters

nSince 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 com-

mand type and your checksum setting.

Field Number of Bytes Content

Header 2 <STX><STX> (02H, 02H)

Command Size 2 Packet length in bytes excluding the header, command

size, checksum and terminator bytes.

Command 1 Command Code

(Data) variable command data/parameters

(Checksum) 1 Optional Checksum

Terminator 1 <ETX> (03H)

Following a successful operation, the LRP820 will respond with the follow-

ing. The data field and the checksum may not be present depending on your

checksum setting.

Field Number of Bytes Content

Header 2 <STX><STX> (02H, 02H)

Response Size 2 Packet length in bytes excluding the header, response

size, checksum and terminator bytes.

Command 1 Command Echo

(Data) variable response data

(Checksum) 1 Optional Checksum

Terminator 1 <ETX> (03H)

LRP820-Series Long-Range Passive Reader/Writer 89

6.5 ABx Fast Protocol

If the LRP820 Reader/Writer encounters a fault it will respond with the fol-

lowing:

Field Number of Bytes Content

Header 2 <STX><STX> (02H, 02H)

Response Size 2 Packet length in bytes excluding the header, packet

size, checksum and terminator bytes.

Error Flag 1 FFH

Error Code 1 Hex error code, see Table 7 for details

(Checksum) 1 Optional Checksum

Terminator 1 <ETX> (03H)

nThe Header and Terminator are always STX-STX and ETX

respectively.

nAll other bytes are interpreted as binary data (0 - 255 dec).

nFields 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 com-

mand. All parameters and data between the Command/Response Size and

the Checksum or Terminator bytes must be accounted for in the com-

mand/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 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.

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.

LRP820-Series Long-Range Passive Reader/Writer 91

Command from Host

Field Contents

Header

02H

Command Size 00H

03H

Command Code 01H

Timeout 07H

D0H

Checksum 24H

Terminators <ETX> 03H

Sum these values to calculate

the checksum

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 incre-

ments and can have a value of 1EH to FFFEH (65,534 ms). When the time-

out is set to 0, the LRP820 will return a syntax error.

Field Content

Header <STX><STX>

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 <ETX>

A response to a successful command will follow this form.

Field Content

Header <STX><STX>

Command Size Packet length in bytes excluding the header, command size, checksum and

terminator bytes.

Command 04H

Checksum Optional Checksum

Terminator <ETX>

92 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 in-

crements) is set for the completion of the configuration.

LRP820-Series Long-Range Passive Reader/Writer 93

Command from Host

Field Contents

Header

02H

Command Size 00H

08H

Command Code 04H

Start address 00H

05H

Block Size 00H

28H

Timeout,

2 seconds

07H

D0H

Data Value Byte 41H

Checksum AEH

Terminators <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 04H

Checksum FAH

Terminators <ETX> 03H

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 <STX><STX>

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 <ETX>

94 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.

LRP820-Series Long-Range Passive Reader/Writer 95

Command from Host

Field Contents

Header

02H

Command Size 00H

07H

Command Code 05H

Start address 00H

01H

Block size 00H

04H

Timeout,

2 seconds

07H

D0H

Checksum 17H

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

05H

Command Echo 05H

Data from

address 0001H

05H

Data from

address 0002H

AAH

Data from

address 0003H

E7H

Data from

address 0004H

0AH

Checksum 55H

Terminator <ETX> 03H

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 trans-

ferred 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 <STX><STX>

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 <ETX>

96 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.

LRP820-Series Long-Range Passive Reader/Writer 97

Command from Host

Field Contents

Header

02H

Command Size 00H

0BH

Command Code 06H

Start address 00H

00H

Block Size 00H

04H

Timeout,

2 seconds

07H

D0H

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 EEH

Terminators <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 06H

Checksum F8H

Terminators <ETX> 03H

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 <STX><STX>

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 <ETX>

98 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.

LRP820-Series Long-Range Passive Reader/Writer 99

Command from Host

Field Contents

Header

02H

Command Size 00H

03H

Command Code 07H

Timeout 07H

D0H

Checksum 1EH

Terminators <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

09H

Command Echo 07H

First ID byte 1EH

Second ID byte 6EH

Third ID byte 3DH

Fourth ID byte C2H

Fifth ID byte 00H

Sixth ID byte 00H

Seventh ID byte 00H

Eighth ID byte 00H

Checksum 64H

Terminators <ETX> 03H

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 <STX><STX>

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 <ETX>

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.

100 LRP820-Series Long-Range Passive Reader/Writer

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 08H

Checksum F6H

Terminators <ETX> 03H

Command from Host

Field Contents

Header

02H

Command Size 00H

03H

Command Code 08H

Timeout 07H

D0H

Checksum 1DH

Terminators <ETX> 03H

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 param-

eters: 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

LRP820-Series Long-Range Passive Reader/Writer 101

The command is formatted as follows.

Field Content

Header <STX><STX>

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

Reads

Delay value given in 1 second units

Checksum Optional Checksum

Terminator <ETX>

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.

102 LRP820-Series Long-Range Passive Reader/Writer

Command from Host

Field Contents

Header

02H

Command Size 00H

06H

Command Code 0DH

Start Address 00H

01H

Read Length 00H

08H

Delay Between Identical

Decodes

02H

Checksum E1H

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 0DH

Checksum F1H

Terminator <ETX> 03H

The LRP820 will first return an acknowledgment of the command followed

by a response containing read data when a tag enters the antenna field.

LRP820-Series Long-Range Passive Reader/Writer 103

Response from LRP820

Field Contents

Header

02H

Command Size 00H

09H

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

Terminator <ETX> 03H

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=ONand

0 = OFF. The following chart shows the hex values for all output high com-

binations. To reset all output, issue the command with 0000H for the Output

Pattern byte.

Field Content

Header <STX><STX>

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 <ETX>

104 LRP820-Series Long-Range Passive Reader/Writer

MSB LSB Remarks LSB Bit 3

Output D

LSB Bit 2

Output C

LSB Bit 1

Output B

LSB Bit 0

Output A

00H 00H Reset A, B, C, D 0000

00H 01H Set Output A - Reset B, C, D 0001

00H 02H Set Output B - Reset A, C, D 0010

00H 03H Set Output A, B - Reset C, D 0011

00H 04H Set Output C - Reset A, B, D 0100

00H 05H Set Output A, C - Reset B, D 0101

00H 06H Set Output B, C - Reset A, D 0110

00H 07H Set Output A, B, C - Reset D 0111

00H 08H Set Output D - Reset A, B, C 1000

00H 09H Set Output A, D - Reset B, C 1001

00H 0AH Set Output B, D - Reset A, C 1010

00H 0BH Set Output A, B, D - Reset C 1011

00H 0CH Set Output C, D - Reset A, B 1100

00H 0DH Set Output A, C, D - Reset B 1101

00H 0EH Set Output B, C, D - Reset A 1110

00H 0FH Set Output A, B, C, D 1111

EXAMPLE

The following example sets Output B only and resets A, C, and D.

LRP820-Series Long-Range Passive Reader/Writer 105

Command from Host

Field Contents

Header

02H

Command Size 00H

02H

Command Code 10H

Output Value Byte 02H

Checksum EBH

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 10H

Checksum EEH

Terminator <ETX> 03H

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=ONand

0 = OFF. The following chart shows all possible conditions that can be

returned in the response.

Field Content

Header <STX><STX>

Command Size Packet length in bytes excluding the header, command size, checksum and

terminator bytes.

Command 11H

Checksum Optional Checksum

Terminator <ETX>

106 LRP820-Series Long-Range Passive Reader/Writer

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 0000

00H 01H Input A, ON - B, C, D, OFF 0001

00H 02H Input B, ON - A, C, D, OFF 0010

00H 03H Input A, B, ON - C, D, OFF 0011

00H 04H Input C, ON - A, B, D, OFF 0100

00H 05H Input A, C, ON - B, D, OFF 0101

00H 06H Input B, C, ON - A, D, OFF 0110

00H 07H Input A, B, C, ON - D, OFF 0111

00H 08H Input D, ON - A, B, C, OFF 1000

00H 09H Input A, D, ON - B, C, OFF 1001

00H 0AH Input B, D, ON - A, C, OFF 1010

00H 0BH Input A, B, D, ON - C, OFF 1011

00H 0CH Input C, D, ON - A, B, OFF 1100

00H 0DH Input A, C, D, ON - B, OFF 1101

00H 0EH Input B, C, D, ON - A, OFF 1110

00H 0FH Input A, B, C, D, ON 1111

EXAMPLE

The following example shows only Input B is ON and A, C, and D are OFF.

LRP820-Series Long-Range Passive Reader/Writer 107

Command from Host

Field Contents

Header

02H

Command Size 00H

01H

Command Code 11H

Checksum EDH

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

02H

Command Echo 11H

Input Value Byte 02H

Checksum EAH

Terminator <ETX> 03H

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 (mul-

tiple 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 suc-

cessful 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 <STX><STX>

Packet Size Packet length in bytes excluding the header, packet size, checksum and ter-

minator 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 <ETX>

NOTE:

This command can not be used over a MUX32 interface.

108 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.

LRP820-Series Long-Range Passive Reader/Writer 109

Command from Host

Field Bytes Contents

Header

02H

Command Size 00H

0AH

Command Code 84H

Family ID 03H

Anticollision Index 02H

Start address 00H

05H

Fill Length 00H

28H

Timeout,

2 seconds

07H

D0H

Data Value Byte 41H

Checksum 27H

Terminator <ETX> 03H

Response from LRP820

Field Bytes Contents

Header

02H

Response Size 00H

03H

Command Echo 84H

Numbers of tags 04H

Status byte 08H

Checksum 6CH

Terminator <ETX> 03H

ABxF Command 85 (85H): Block Read All

DESCRIPTION

Read a block of data from all RFID tags-in-field or all those with the speci-

fied 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 in-

valid 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 <STX><STX>

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 <ETX>

NOTE:

This command can not be used with a MUX32 interface.

110 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.

LRP820-Series Long-Range Passive Reader/Writer 111

Command from Host

Field Contents

Header

02H

Command Size 00H

09H

Command Code 85H

Family ID AAH

Anticollision Index 02H

Start address 00H

01H

Block size 00H

02H

Timeout,

2 seconds

07H

D0H

Checksum EBH

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo/Tag 1 85H

Data from

address 0001H

05H

Data from

address 0002H

AAH

Checksum C8H

Terminator <ETX> 03H

Header

02H

Response Size 00H

03H

Command Echo/Tag 2 85H

Data from

address 0001H

05H

Data from

address 0002H

AAH

Checksum C8H

Terminator <ETX> 03H

Header

02H

Response Size 00H

03H

Command Status FFH

Number of tags 02H

Status Byte 08H

Checksum F3H

Terminator <ETX> 03H

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 contigu-

ous 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 ad-

dress 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 suc-

cessfully completed on 1 tag, or when the timeout expires.

Field Content

Header <STX><STX>

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 <ETX>

NOTE:

This command can not be used over a MUX32 interface.

112 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 writ-

ten to. The Anticollision Index is 4, expecting 32-64 tags. Five tags are

written to.

LRP820-Series Long-Range Passive Reader/Writer 113

Command from Host

Field Contents

Header

02H

Command Size 00H

0DH

Command Code 86H

Family ID 00H

Anticollision Index 04H

Start address 00H

00H

Block Size 00H

04H

Timeout,

2 seconds

07H

D0H

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 <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 86H

Number of Tags 05H

Status Byte 08H

Checksum 69H

Terminator <ETX> 03H

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 opera-

tion is successfully completed to 1 tag, or when the timeout expires. No spe-

cial termination packet is sent upon successful completion if Anticollision

Index is set to 0.

Field Content

Header <STX><STX>

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 <ETX>

NOTE:

This command can not be used with a MUX32 interface.

114 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.

LRP820-Series Long-Range Passive Reader/Writer 115

Command from Host

Field Contents

Header

02H

Command Size 00H

05H

Command Code 87H

Family ID 00H

Anticollision Index 01H

Timeout 07H

D0H

Checksum 9BH

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

09H

Command Echo 87H

SN byte 1 1EH

SN byte 2 6EH

SN byte 3 3DH

SN byte 4 C2H

SN byte 5 00H

SN byte 6 00H

SN byte 7 00H

SN byte 8 00H

Checksum E4H

Terminator <ETX> 03H

Header

02H

Response Size 00H

03H

Command Status FFH

Number of Tags 01H

Status Byte 08H

Checksum F4H

Terminator <ETX> 03H

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 <STX><STX>

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 <ETX>

NOTE:

This command can not be used over a MUX32 interface.

116 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.

LRP820-Series Long-Range Passive Reader/Writer 117

Command from Host

Field Contents

Header

02H

Command Size 00H

05H

Command Code 88H

Family ID 00H

Anticollision Index 02H

Timeout 07H

D0H

Checksum 99H

Terminators <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 88H

Number of Tags 01H

Status byte 00H

Checksum 73H

Terminators <ETX> 03H

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 mul-

tiple tag-in-field is disabled, the LRP820 will return a response when it reads

a tag or the timeout expires.

Field Content

Header <STX><STX>

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 <ETX>

118 LRP820-Series Long-Range Passive Reader/Writer

EXAMPLE

This example assumes that the tags-in-field are not enabled for the EAS fea-

ture. 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 com-

mand is issued, 5 tags with Family ID 09H are found and enabled for EAS.

LRP820-Series Long-Range Passive Reader/Writer 119

Command from Host

Field Contents

Header

02H

Command Size 00H

05H

Command Code 89H

Family ID 09H

Anticollision Index 02H

Timeout 07H

D0H

Checksum 8FH

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 89H

Number of Tags 05H

Status byte 08H

Checksum 66H

Terminator <ETX> 03H

ABxF Command 8A (8AH): EAS Start/Stop

DESCRIPTION

If are using the EAS feature in your application, the EAS Start/Stop com-

mand 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 com-

mand 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 trig-

ger 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 fol-

lowing 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 exe-

cuted until EAS has been stopped.

Field Content

Header <STX><STX>

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 <ETX>

120 LRP820-Series Long-Range Passive Reader/Writer

EXAMPLE

This example starts EAS mode. Three responses follow. The first is a com-

mand 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.

When an EAS-enabled tag enters the antennas’ field, the LRP820 responds

with an EAS tag-in-field response.

LRP820-Series Long-Range Passive Reader/Writer 121

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 8AH

Number of Tags FFH

Status byte 00H

Checksum 73H

Terminator <ETX> 03H

Command from Host

Field Contents

Header

02H

Command Size 00H

03H

Command Code 8AH

Family ID 00H

Anticollision Index 00H

Checksum 72H

Terminator <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 8AH

Number of Tags 01H

Status byte 00H

Checksum 71H

Terminator <ETX> 03H

When all EAS-enabled tags have left the field, the LRP820 will send the fol-

lowing response.

122 LRP820-Series Long-Range Passive Reader/Writer

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 8AH

Number of Tags 00H

Status byte 00H

Checksum 72H

Terminator <ETX> 03H

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 Continu-

ous 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 <STX><STX>

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 <ETX>

NOTE:

This command can not be used with a MUX32 interface>

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.

124 LRP820-Series Long-Range Passive Reader/Writer

Response from LRP820

Field Contents

Header

02H

Response Size 00H

01H

Command Echo 8DH

Checksum 71H

Terminator <ETX> 03H

Command from Host

Field Contents

Header

02H

Command Size 00H

08H

Command Code 8DH

Family ID 00H

Anticollision Index 01H

Start Address 00H

01H

Read Length 00H

04H

Tag Delay 14H

Checksum 50H

Terminator <ETX> 03H

After the LRP820 sends the acknowledgment, it will send the read data from

the 2 tags.

LRP820-Series Long-Range Passive Reader/Writer 125

Response from LRP820

Field Contents

Header

02H

Response Size 00H

05H

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 <ETX> 03H

Header

02H

Response Size 00H

03H

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 <ETX> 03H

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 mul-

tiple 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 Bit Description

LockLSB 0 Tag bytes 0-3

1 Tag bytes 4-7

2 Tag bytes 8-11

3 Tag bytes 12-15

4 Tag bytes 16-19

5 Tag bytes 20-23

6 Tag bytes 24-27

7 Tag bytes 28-31

LockMSB 8 Tag bytes 32-35

9 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

126 LRP820-Series Long-Range Passive Reader/Writer

The command is formatted as shown below.

Field Remarks

Header <STX><STX>

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 <ETX>

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.

LRP820-Series Long-Range Passive Reader/Writer 127

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 8EH

Number of Tags 02H

Status byte 08H

Checksum 64H

Terminator <ETX> 03H

Command from Host

Field Contents

Header

02H

Command Size 00H

07H

Command Code 8EH

Family ID 02H

Anticollision Index 01H

Timeout 07H

D0H

LockMSB 00H

LockLSB 01H

Checksum 8FH

Terminator <ETX> 03H

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 <STX><STX>

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 <ETX>

128 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 config-

uration.

LRP820-Series Long-Range Passive Reader/Writer 129

Command from Host

Field Contents

Header

02H

Command Size 00H

0EH

Command Code 94H

Family ID 00H

Anticollision Index 02H

Timeout 07H

D0H

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 <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 94H

Number of Tags 01H

Status byte 00H

Checksum 67H

Terminators <ETX> 03H

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 time-

out 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 <STX><STX>

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 <ETX>

130 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.

LRP820-Series Long-Range Passive Reader/Writer 131

Command from Host

Field Contents

Header

02H

Command Size 00H

11H

Command Code 95H

Family ID AAH

Anticollision Index 02H

Start address 00H

01H

Block size 00H

02H

Timeout,

2 seconds

07H

D0H

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

Checksum A3H

Terminator <ETX> 03H

Response from LRP820, tag found

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 95H

Data from

address 0001H

05H

Data from

address 0002H

AAH

Checksum B8H

Terminator <ETX> 03H

Response from LRP820, tag not found

Field Contents

Header

02H

Response Size 00H

03H

Command Fail FFH

Ntag 00H

Status byte 08H

Checksum B8H

Terminator <ETX> 03H

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 contigu-

ous 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 <STX><STX>

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 <ETX>

132 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.

LRP820-Series Long-Range Passive Reader/Writer 133

Command from Host

Field Contents

Header

02H

Command Size 00H

15H

Command Code 96H

Family ID 03H

Anticollision Index 03H

Start address 00H

00H

Block Size 00H

04H

Timeout,

2 seconds

07H

D0H

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

Checksum 1EH

Terminators <ETX> 03H

Response from LRP820

Field Contents

Header

02H

Response Size 00H

03H

Command Echo 96H

Number of tags 01H

Status byte 00H

Checksum 65H

Terminators <ETX> 03H

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 speci-

fied Family ID. Data will be returned with the serial number of the corre-

sponding tag.