Nedap N V PAGSLS Remote Alarm Notification device User Manual MD Pager Transmitter v1 00

N. V. Nederlandsche Apparatenfabriek NEDAP Remote Alarm Notification device MD Pager Transmitter v1 00

user manual

Date: 27 May 2004 Version 1.00

This information is furnished for guidance, and with no guarantee as to its accuracy or completeness; its publication conveys no license under any patent or other right, nor does

the publisher assume liability for any consequence of its use; specifications and availability of goods mentioned in it are subject to change without notice; it is not to be

reproduced in any way, in whole or in part, without the written consent of the publisher.

_________________________________________________________________________________________________________

Metal Detection Pager - Transmitter

MD Pager - Transmitter V1.00 | Nedap Retail Support

- support-rs@nedap.com

- H. Hammer

+31 (0) 544-47 15 19

hans.hammer@nedap.com

- H. Broekhuis

+31 (0) 544-47 15 02

han.broekhuis@nedap.com

Visitor’s address:

Nedap Retail Support

Parallelweg 2d

Groenlo

Netherlands

Postal address:

Nedap Retail Support

Postbus 102

7140 AC Groenlo

Fax

+31 (0) 544-46 58 14

Parallelweg 2d, 7141 DC Groenlo

The software / hardware described in this book / file is furnished under a license agreement and may be used only in accordance with the terms of

the agreement.

Documentation version 1.00

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Other product names mentioned in this manual may be trademarks or registered trademarks of their respective companies and are hereby

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Printed in the Netherlands

Technical Support:

MD Pager - Transmitter V1.00 | Nedap Retail Support

Technical Support: 2

Visitor’s address: 2

Postal address: 2

Fax 2

Table of content 3

General 4

Block diagram 5

Wireless Alarm Transmitter art. No. 8008272 5

Wireless Alarm Receiver art. No. 8008299 5

Transmitter Unit and PCB 6

RX Pager Unit and PCB 7

Datasheet TXM 433 Transmitter Module 8

Datasheet SILRX Receiver Module 19

Table of content

MD Pager - Transmitter V1.00 | Nedap Retail Support

The Wireless Alarm unit is intended to transmit an alarm, OST or MD, to a small

handheld receiver unit. The Transmitter unit is supplied with 24Vdc from the NCC or IQ

or EQ unit. One of the alarm relays on the NCC , IQ or EQ unit is then wired tot the input

of the transmitter board, for instance connector K3 between GND and input 1. A short

pulse of a normally open contact is enough to trigger a short burst of data onto 433Mc.

This data consists of an address and alarm number (1, 2, 3 or 4).

In the handheld receiver this burst is detected and the alarm will sound in addition one of

the led’s will light for a couple of seconds which indicates the alarm input that is

triggered.

If necessary an opto coupled input is also available on the transmitter. In this case 24V

has to be supplied to the appropriate input.

Both, the transmitter and the receiver are equipped with an address switch to its possible

to use more than one transmitter receiver combinations in the same “shop”.

The battery in the receiver has to be charged regularly, for this purpose the receiver has

a battery charge input with charge led. While charging the pager does not function.

The working range depends on the location of the transmitter and the total construction

of the building. A range of 10 to 20 meters is practical and must give a sure alarm.

General

MD Pager - Transmitter V1.00 | Nedap Retail Support

Wireless Alarm Transmitter art. No. 8008272

pic

16c84

TX mod.

TXM-433

opto

coupler

oc in

3,84MHz

Either an opto coupled or a normal input is triggered and translated in a code by the pic.

This code will be transmitted via a standard transmitter module on 433 MHz.

Wireless Alarm Receiver art. No. 8008299

pic

16c84

RX mod.

SILRX-433

3,84MHz

A standard 433 MHz receiver module receives the alarm data and output it to a pic

16c84. The pic will read the code and will turn on the appropriate led and gives audible

alarm.

Block diagram

MD Pager - Transmitter V1.00 | Nedap Retail Support

Transmitter Unit and PCB

MD Pager - Transmitter V1.00 | Nedap Retail Support

RX Pager Unit and PCB

MD Pager - Transmitter V1.00 | Nedap Retail Support

Datasheet TXM 433 Transmitter Module

Radiometrix Ltd, TXM Data Sheet page 1

Typical features include:

CE Certified by independent Notified Body

Verified to comply with harmonised radio standard ETSI EN 300 220-3 and EMC

standard ETSI EN 301 489-3 by accredited Test Laboratory

PCB Mounting, space saving SIL style

SAW controlled wide band FM transmission

High data rates, 5kbps and 10kbps versions

Analogue or Digital data input

Wide supply range 2.7V-4.0 or 6.0V-9.0V @ <17mA

The transmitter modules are most commonly employed in Wireless Security systems. The transmitter

and the matching receiver (RX2) are approved to harmonised radio standard ETSI EN 300 220-3 and

EMC standard ETSI EN 301 489-3. The TXM and RX2 modules will suit one-to-one and multi-node

wireless links in applications including car and building security, EPOS and inventory tracking, remote

industrial process monitoring and computer networking. Because of their small size and low power

requirements, both modules are ideal for use in portable, battery-powered applications such as hand-

held terminals.

Typical applications include :-

Domestic and commercial security

Guard patrol / lone worker protection

Medical Alert / Nurse Call systems

Mobile panic attack

Computer networking

Remote industrial process monitoring

Data transfer through hazardous environments

Lighting control, Garage door openers

Fire alarms

Picture / antique protection alarms

Remote control, Access control

The TXM-433-5 and TXM-433-10 integrate a low

power FM UHF radio transmitter on a small

module. Together with the matching RX2-433-14 or

RX2-433-40 receiver a one-way radio data link can be

achieved over a distance up to 200 metres on open

ground.

TXM-433-10 transmitter (back & front view)

Radiometrix

Hartcran House, Gibbs Couch, Watford, WD19 5EZ, England

Issue 5, February 2002 TXM-433

UHF Radio Telemetry Transmit Module

UHF Radio Telemetry Transmit ModuleUHF Radio Telemetry Transmit Module

UHF Radio Telemetry Transmit Module

Tel: +44

(

)

20 8428 1220, Fax: +44

(

)

20 8428 1221

Radiometrix Ltd, TXM Data Sheet page 2

Brief description

The TXM is designed to work with the matching SILRX receiver. With the addition of simple antenna

the pair may be used to transfer serial data up to 200m. The range of the radio link is very variable and

depends upon many factors, principally, the type of antenna employed and the operating environment.

The 200m quoted range is a reliable operating distance over open ground using 1/4 whip antenna at

both ends of the link at 1.5m above ground. Smaller antenna, interference or obstacles (e.g. building

etc.) will reduce the reliable working range (down to 30m in extreme cases). Increased antenna height,

slow data or a larger receive antenna will increase the range (our best is 3km).

Pin Description

pin 1 RF GND This pin should be connected to the ground plane against which

the integral antenna radiates. It is internally connected to pin 4.

pin 2 RF OUT Connects to the integral antenna. Output impedance is 50Ω.

pin 3 Vcc Positive supply , supply voltages from +6V to +9V may be used.

pin 4 Vss 0V connection for the modulation and supply.

pin 5 DATA IN Should be driven directly by a CMOS logic device running on the

same supply voltage as the module.

figure 1: TXM’s block diagram

figure 2: mechanical dimensions

Radiometrix Ltd, TXM Data Sheet page 3

Performance data TXM-433-5

Absolute Maximum Ratings:

Supply voltage Vcc pin 3 -0.7V to + 12V

Modulation input pin 5 -0.7V to + 9V

Operating temperature -10 °C to + 55 °C

Storage temperature -40 °C to + 100 °C

Performance Data:

ambient temperature: 20°C

supply voltage: +8.0V, unless noted otherwise

test circuit: figure 3

Parameter Min Typical Max Units Notes

Operating supply range (Vcc) 6.0 - 9.0 V -

Supply current, Vcc = 6.0V 3.0 6.0 10.0 mA -

Vcc = 9.0V 5.0 10.0 17.0 mA -

Radiated power (ERP) Vcc = 6.0V -16 -10 -7 dBm 1

Vcc = 9.0V -13 -8 -5 dBm 1

Transmit frequency (Frf) 418.00 / 433.92 MHz -

Initial frequency accuracy -80 - +80 kHz -

Overall frequency accuracy -95 - +95 kHz 2

Spurious radiation Meets the EN300 220-1 standard 3

FM deviation (+/-) 15 25 40 kHz 4

Modulation Bandwidth (-3dB) analogue DC - 10 kHz 4

Modulation digital pulse width 100 - - µs 5

Notes

1. Module on 50mm square ground plane, helical antenna

2. Supply 6V to 9V, temp -10°C to +55°C.

3. <-54 dBm in bands 41-68, 87.5-118, 162-230 & 470-862 MHz

<-36 dBm else where below 1GHz , <-30dBm above 1GHz

4. Standard modulation: 2kHz square wave, 0 to Vcc

5. High or Low pulse.

figure 3: TXM 5kbps version test circuit

Radiometrix Ltd, TXM Data Sheet page 4

Performance data TXM-418-10 and TXM-433-10

Absolute Maximum Ratings:

Supply voltage Vcc pin 3 -0.7 to + 6V

Modulation input pin 5 -0.7 to + 13V

Operating temperature -10°C to + 55°C

Storage temperature -40°C to + 100°C

Performance Data:

ambient temperature: 20 °C

supply voltage: 3.0V, unless noted otherwise

test circuit: figure 4

Parameter Min Typical Max Units Notes

Operating supply range (Vcc) 2.7 3.2 4 V -

Supply current,Vcc = 2.7V 3.0 6.0 13.0 mA -

Vcc = 4.0V 5.0 10.0 17.0 mA -

Conducted power in to 50 Ω, Vcc = 2.7V - -5 - dBm 1

Vcc = 3.6V - 0 - dBm 1

Transmit frequency (Frf) 433.92 MHz -

Initial frequency accuracy -85 0 +85 kHz -

Overall frequency accuracy -95 0 +95 kHz 1

Spurious radiation 2

FM deviation (+/-) 15 25 40 kHz 3

Modulation Bandwidth (-3dB) analogue DC - 20 kHz 3

Modulation digital pulse width 50 - - µs 4

Notes

1. Supply 2V to 3.6V, temp -10°C to +55°C.

2. <-54 dBm in bands 41-68, 87.5-118, 162-230 & 470-862 MHz

<-36 dBm else where below 1GHz , <-30dBm above 1GHz

3. Standard modulation: 2kHz square wave, 0 to Vcc

4. High or Low pulse.

Radiometrix Ltd, TXM Data Sheet page 5

The TXM-UHF transmitter requires only a data modulation input, supply, ground and an antenna.

Power supply requirements

• The module will operate over the range 6V to 9V and is typically powered by either 9 Volt 'PP3'.

• The module is not reverse polarity protected. Reverse supply voltages higher than 2V will cause

damage and must therefor be externally protected against.

Modulation requirements

• The TXM-UHF transmitter has a DC to 10kHz modulation bandwidth and will accept direct

analogue (AFSK) or digital data. A modulation low-pass filter (10kHz @ -6dB, 1st order) is use

internally.

• Although the modulation bandwidth of the transmitter extends down to DC as does the AF output of

the receivers, it is not possible to pass data with a DC component due to frequency errors & drifts

between the transmitter and receiver. Frequency differences between the transmitter and receiver

will produce a DC offset error which causes the data slicer in the receiver module to give errors on

long high or low pulses which exceed the maximum pulse width, see the receiver's data sheet for

more detailed information.

figure 4: TXM 10kbps version test circuit

figure 5: Typical performance curves

Radiometrix Ltd, TXM Data Sheet page 6

• Data Input, pin 5, is normally driven directly by CMOS logic levels from a data encoder IC. There is

a wide range of encoder/decoder IC’s available which may be used with the modules:

MM57C200, 57410 National Semiconductor

UM3750 UMC

HT12 series Holtek

MC14026 Motorola

AS2787 Austria Systeme International GmbH

• The encoder normally being run on the same supply voltage as the transmitter. Analogue drive eg. 2

tone FSK, is also possible, the pk to pk level should be between 5V and 9V peak to peak and must not

drive pin 5 below 0V. There will be some 2nd harmonic distortion due to the varactor modulator (typ.

<15%), this may be reduced if necessary by predistortion of the analogue waveform

Antenna requirements

Three types of integral antenna are recommended and approved for use with the module:

A) Helical: Wire coil, connected directly to pin 2, open circuit at other end. This antenna is very

efficient given it's small size (20mm x 4mm dia.). The helical is a high Q antenna, trim

the wire length or expand the coil for optimum results. The helical de-tunes badly with

proximity to other conductive objects.

B) Loop, A loop of PCB track tuned by a fixed or variable capacitor to ground at the 'hot' end and

fed from pin 2 at a point 20% from the ground end. Loops have high immunity to

proximity de-tuning.

C) Whip This is a wire, rod ,PCB track or combination connected directly to pin 2 of the module.

Optimum total length is 17cm (1/4 wave @ 418MHz) Keep he open circuit (hot) end well

away from metal components to prevent serious de-tuning. Whips are ground plane

sensitive and will benefit from internal 1/4 wave earthed radial(s) if the product is small

and plastic cased

Antenna selection chart

A B C

helical loop whip

Ultimate performance ** * ***

Easy of design set-up ** * ***

Size *** ** *

Immunity proximity effects ** *** *

Range open ground to similar antenna 80m 50m 120m

The antenna choice and position directly controls the system range. Keep it clear of other metal in the

system, particularly the 'hot' end. The best position by far, is sticking out the top of the product. This is

often not desirable for practical/ergonomic reasons thus a compromise may need to be reached. If an

internal antenna must be used try to keep it away from other metal components, particularly large ones

like transformers, batteries and PCB tracks/earth plane. The space around the antenna is as important

as the antenna itself.

Radiometrix Ltd, TXM Data Sheet page 7

Duty Cycle requirements

The duty cycle is defined as the ratio, expressed as a percentage, of the maximum transmitter “on” time

on one or more carrier frequencies, relative to a one hour period. Where an acknowledgement message

is required, the additional transmitter “on” time shall be included.

There is a 10% duty cycle restriction on 433.050-434.790 MHz band in most of the EU member states.

The TXM-433 is a RF module intended to be incorporated into a wide variety of applications and

finished products, Radiometrix has no control over the end use of the TXM-433.The harmonised band

433.050 to 434.790 MHz as detailed in Annex 1 Band E of CEPT/ERC Recommendation 70-03 (which

can be downloaded at http://www.ero.dk/scripts/docmanag98/dm.dll/QueryDoc?Cat=Recommendation)

has list of countries where Duty Cycle restriction apply.

Module users should, therefore, ensure that they comply with the stated Duty Cycle requirements of the

version of CEPT/ERC Recommendation 70-03 in place at the time of incorporation of the TXM-433 into

their product. It should be noted that the stated Duty Cycle must not be exceeded otherwise any

approval granted for the TXM-433 will be invalidated.

figure 6: Antenna configurations

Radiometrix Ltd, TXM Data Sheet page 8

Ordering information

The following are standard:

TXM-433-5 5kbps data rate Transmitter

RX2-433-14-5V 14kbps data rate matching Receiver

RX2-433-40-5V 40kbps data rate matching Receiver

SILRX-433-5 5kbps data rate matching Receiver

TXM-433-10 10kbps data rate Transmitter

RX2-433-14-5V 14kbps data rate matching Receiver

RX2-433-40-5V 40kbps data rate matching Receiver

SILRX-433-10 10kbps data rate matching Receiver

3V versions of the RX2 receivers are available and should be ordered with a -3V suffix on the part

number. (e.g. RX2-433-14-3V is set-up for 3V to 4V operation)

All modules are available in a 418MHz version for UK use.

Radiometrix Ltd, TXM Data Sheet page 9

CE Certificate of TXM and its variants

Radiometrix Ltd

Hartcran House, Gibbs Couch,

Watford, WD19 5EZ, ENGLAND

Tel: +44 (0)20 8428 1220,

Fax: +44 (0)20 8428 1221

info@radiometrix.co.uk

www.radiometrix.co.uk

This product data sheet is the original work and copyrighted property of Radiometrix Ltd.

Reproduction in whole or in part must give clear acknowledgement to the copyright owner.

Limitation of liability

The information furnished by Radiometrix Ltd is believed to be accurate and reliable.

Radiometrix Ltd reserves the right to make changes or improvements in the design, specification

or manufacture of its subassembly products without notice. Radiometrix Ltd does not assume

any liability arising from the application or use of any product or circuit described herein, nor

for any infringements of patents or other rights of third parties which may result from the use of

its products. This data sheet neither states nor implies warranty of any kind, including fitness

for any particular application. These radio devices may be subject to radio interference and may

not function as intended if interference is present. We do NOT recommend their use for life

critical applications.

The Intrastat commodity code for all our modules is: 8542 6000

R&TTE Directive

After 7 April 2001 the manufacturer can only place finished product on the market under the

provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive may

demonstrate compliance to the essential requirements specified in Article 3 of the Directive, as

appropriate to the particular equipment.

Further details are available on Radiocommunications Agency (RA) web site:

http://www.radio.gov.uk/topics/conformity/conform-index.htm

The Library and Information Service

The Radiocommunications Agency

Wyndham House

189 Marsh Wall

London

United Kingdom

E14 9SX

Tel: +44 (0)20 7211 0502/0505

Fax: +44 (0)20 7211 0507

library@ra.gsi.gov.uk

For further information on radio matters

contact the Agency's 24 Hour Telephone

Enquiry Point: +44 (0)20 7211 0211

European Radiocommunications Office (ERO)

Midtermolen 1

DK 2100 Copenhagen

Denmark

Tel. +45 35250300

Fax +45 35250330

ero@ero.dk

www.ero.dk

MD Pager - Transmitter V1.00 | Nedap Retail Support

Datasheet SILRX Receiver Module

Radiometrix Ltd, SILRX-UHF Data Sheet page 1

Typical features include:

• PCB mounting, space saving SIL style

• 418 MHz SAW controlled wide band FM reception

• Selective double conversion superhet

• Sensitive typ. 0.5µV (-113 dBm) for 20 dB S/N

• High data rates, 5kbps and 10kbps

• Analogue and Digital data outputs

• Carrier detect output

• Fast enable time,< 3ms for duty cycle power save use

• Wide supply range, 4.0V to 9.0V

• Low current, 13 mA continuous, 130µA on power save (100:1)

• The SILRX radio receiver and the matching DTI (RA) approved transmitter (TXM-418-5) are self

contained, PCB mounting modules capable of transferring analogue or digital data up to a distance

of 200m.

The SILRX receiver module is particularly suitable for battery powered portable applications where it’s

low power requirements and small size are of advantage. It may also be used as a lower cost option to

the RXM-418-10 in fixed applications where the higher data rates and signal strength output of the

RXM-418-10 are not required.

Typical applications include:-

Site paging receivers Paging car alarms

Line powered telephone auto diallers Domestic and commercial security

Guard patrol/lone worker protection Medical Alert/Nurse Call system

Mobile panic attack Remote industrial process monitoring

Battery powered half duplex data networks Data transfer through hazardous environments

Lighting control, Garage door openers Fire alarms

Picture/antique protection alarms Remote control, Access control

The SILRX-418-5 and SILRX-433-5 integrate a

omplete FM superhet UHF radio receiver on a

small module. Together with the matching TXM-

418-5 or TXM-433-5 transmitter a one-way radio

ata link can be achieved over a distance upto 200

metres on open ground

UK version: SILRX-418-5 / SILRX-418-10

Euro version: SILRX-433-5 / SILRX-433-10

left: TXM-418-5 transmitter right: SILRX-418-5 receiver

Radiometrix

Hartcran House, Gibbs Couch, Watford, WD19 5EZ, England

Issue 3, 13 April 2001 SILRX-UHF

UHF Radio Telemetr

Receiver Module

Tel: +44 (0) 20 8428 1220, Fax: +44 (0) 20 8428

Radiometrix Ltd, SILRX-UHF Data Sheet page 2

Brief description

The SILRX receiver is a double conversion FM superhet with a data slicer driven by the AF output.

Additionally a fast acting carrier detect signal is available to indicate to external circuits that a signal is

present. This signal is extremely useful when implementing duty cycle power save circuits (see fig 4) or

to indicate to external logic that a signal is being received. It is internally derived from the degree of

noise quieting due to the presence of a receive carrier.

The SILRX-418 is designed to work with the matching transmitter (TXM-418). With the addition of

simple antenna the pair may be used to transfer serial data up to 200m. The range of the radio link is

very variable and depends upon many factors, principally, the type of antenna employed and the

operating environment. The 200m quoted range is a reliable operating distance over open ground using

1/4 whip antenna at both ends of the link at 1.5m above ground. Smaller antenna, interference or

obstacles (e.g. building etc.) will reduce the reliable working range (down to 30m in extreme cases).

Increased antenna height, slow data or a larger receive antenna will increase the range (our best is

3km).

We recommend that the module evaluation kit, EVAL-418-A, can be used to assess the reliable working

range under the anticipated conditions of use.

The following figure shows the receiver’s block diagram.

figure 1: Block diagram

figure 2: Test cicuit

Radiometrix Ltd, SILRX-UHF Data Sheet page 3

Pin Description

pin 1 RF IN The receiver antenna connects to this input. It has nominal RF

impedance of 50Ω and is capacitively isolated from the internal circuit

pin 2 RF GROUND This pin should be connected to any ground plane against which the

antenna works. It is internally connected to pin 4.

pin 3 DETECT This pin may be used to derive a carrier detect to enable external circuits

when a signal is being received. If the detect function is not being used a

10 kΩ pull-up to pin 5 (Vcc) should be connected. Refer to applications

note for further details on the use of this pin.

pin 4 0 volt Ground for supply.

pin 5 Vcc Positive supply of 4V to 9V 13 mA. The supply must be clean (<2mV pp)

stable and free of high frequency digital noise. A supply filter is

recommended unless the module is driven from it’s own regulated supply.

pin 6 AF This is the FM demodulator output. It has an standing DC bias of

approximately 1.4V and may be used to drive analogue data detectors

such as modem chips or DTMF decoders. Load impedances as low as 2 kΩ

and up to 100 pF can be driven

pin 7 DATA This digital output from the internal data slicer is a squared version of

the signal on pin 6 (AF) This signal is used to drive external digital

decoders, it is true data (i.e. as fed to the transmitters data input). Load

impedances as low as 1 kΩ and up to 1 nF can be driven

figure 3: Mechanical Dimensions:

Radiometrix Ltd, SILRX-UHF Data Sheet page 4

Performance data SILRX-418-5 and SILRX-433-5

ambient temperature: 20°C

supply voltage: + 5 Volt

test circuit: fig. 2

Parameter Min. Typical Max. Units Notes

eratin

volta

e ran

(

Vcc

)

in 5 4.0 5.0 9.0 V -

Supply current pin 5 11 14 17 mA -

Receive frequency - 433.92 - MHz -

Overall frequency accuracy - 100 0 + 100 kHz 1

Sensitivity for 20 dB S/N pin 1 - 0.5 1.0 µV 2

Carrier detect, threshold pin 1 - 0.5 2.0 µV -

RF input impedance pin 1 - 50 - Ω -

IF bandwidth - 250 - kHz 3

AF output level pin 6 - 500 - mVpp 2, 3

AF bandwidth pin 6 DC - 5 kHz 3

Frequency/voltage conversion pin 6 - 10 - mV/kHz -

Data output, Logic low pin 7 0 0.2 0.8 V 4

Logic high pin 7 4.0 4.5 5 V 5

Data bit duration 0.2 - 20 ms 6

Data Mark:Space 20 % - 80 % 7

Data settling time pin 7 - - 15 ms 8

(minimum preamble duration)

Enable time pin 3 - - 2.5 ms 3, 9

Signal detect time pin 3 - - 0.5 ms 3, 9

Notes: 1. over supply and temperature range

2. ±25kHz deviation, 1 kHz tone

3. 3µV input

4. 1mA sink

5. 1mA source

6. time between transitions

7. (time high / time low) * 100 %, averaged over any 20 ms period

8. time from valid carrier detect to stable data output

9. from application of supply to carrier detect low (active)

10. from application of signal to carrier detect low (active)

Absolute maximum ratings:

Supply voltage Vcc, pin 5 - 0.3 to + 10 V

Operating temperature - 10°C to + 50°C

Storage temperature - 40°C to + 100°C

RF input, pin 1 0 dBm

Any input or output pin - 0.3 to Vcc V, ±10 mA

Radiometrix Ltd, SILRX-UHF Data Sheet page 5

Performance data SILRX-418-10 and SILRX-433-10

ambient temperature: 20°C

supply voltage: +5V

test circuit: fig. 2

Parameter Min. Typical Max. Units Notes

Operating voltage range (Vcc) pin 5 4.0 5.0 9.0 V -

Supply current pin 5 11 14 17 mA -

Receive frequency - 433.92 - MHz -

Overall frequency accuracy - 100 0 + 100 kHz 1

Sensitivity for 20 dB S/N pin 1 - 1.0 2.0 µV 2

Carrier detect, threshold pin 1 - 2.0 4.0 µV -

RF input impedance pin 1 - 50 - Ω -

IF bandwidth - 250 - kHz 3

AF output level pin 6 - 500 - mVpp 2, 3

AF bandwidth pin 6 DC - 20 kHz 3

Frequency/voltage conversion pin 6 - 10 - mV/kHz -

Data output, Logic low pin 7 0 0.2 0.8 V 4

Logic high pin 7 4.0 4.5 5 V 5

Data bit duration 0.05 - 2 ms 6

Data Mark:Space 20 % - 80 % 7

Data settling time pin 7 - - 5 ms 8

(minimum preamble duration)

Enable time pin 3 - - 1 ms 3, 9

Signal detect time pin 3 - - 0.3 ms 3, 10

Notes: 1. over supply and temperature range

2. ±25 kHz deviation, 1 kHz tone

3. 3 µV input

4. 1mA sink

5. 1mA source

6. time between transitions

7. (time high / time low) * 100 %, averaged over any 20 ms period

8. time from valid carrier detect to stable data output

9. from application of supply to carrier detect low (active)

10. from application of signal to carrier detect low (active)

Absolute maximum ratings:

Supply voltage Vcc, pin 5 - 0.3 to + 10 V

Operating temperature - 10°C to + 50°C

Storage temperature - 40°C to + 100°C

RF input, pin 1 0 dBm

Any input or output pin - 0.3 to Vcc V, ±10 mA

Radiometrix Ltd, SILRX-UHF Data Sheet page 6

figure 4: Typical performance curves

figure 5: Timing wave forms

Radiometrix Ltd, SILRX-UHF Data Sheet page 7

Antenna configurations

The positioning of the antenna is of the up most importance and is one of the main factors in

determining system range.

The following notes should assist in obtaining optimum performance:-

1. Keep it clear of other metal in the system, particularly the ‘hot’ (top) end.

2. The best position by far, is sticking out the top of the product. This is often not desirable for

practical/ergonomic reasons thus a compromise my need to be reached.

3. If an internal antenna must be used try to keep it away from other metal components, particularly

large ones like transformers, batteries and PCB tracks/earth plane. The space around the antenna is

as important as the antenna itself.

4. Keep it away from interference sources, bad interference can easily reduce system range by a factor

of 5. High speed logic is one of the worst in this respect fast logic edges have harmonics which extend

into the UHF band and the PCB tracks radiate these harmonics most efficiently. Single chip

microprocessors and ground planed logic boards reduce this problem significantly.

The next diagrams (fig 6) show three different antenna configurations which can be used on both the

transmitter and the receiver. Additionally a coax fed external dipole or 1/4 wave ground plane antenna

may be considered if system range is paramount.

figure 6: Antenna configurations

Radiometrix Ltd, SILRX-UHF Data Sheet page 8

Module Mounting considerations

1. The module may be mounted vertically or bent horizontal to the motherboard.

2. No conductive items should be placed within 4 mm of the modules’ component side to prevent

detuning.

3. Observe RF layout practice between the module and it’s antenna i.e. < 10 mm unscreened track,

use 50Ω microstrip or coax for >10mm

4. It is desirable, but not essential, to earth plane all unused area around the module.

5. Mount as far as possible from high frequency interference sources, Microprocessors with

external busses are totally incompatible with sensitive radio receivers and must be keep at least

1 metre from the receive antenna. Single chip micros are not a problem.

6. In some applications it is advantageous to remote the receiver and it’s antenna away from the

main equipment. This avoids any interference problems and allows flexibility in the sighting of

the receive antenna for optimum RF performance.

Using the DETECT output

Pin 3 of the module may be used in several ways:-

1. Pulled up to pin 5 (Vcc) with a 47 kΩ resistor unmutes the AF and DATA outputs for normal

operation.

2. Pulled down to 0 Volts with a 47 kΩ mutes the AF and DATA Outputs (both go to 0V).

3. To drive the base of a PNP transistor (see fig 2) to derive a logic compatible carrier detect. The

data detect output on pin 3 may be used for duty cycle power saving control in portable

equipment where battery life is a problem. By pulsing the receiver on/off the average supply

current may often be reduced by a factor of 20 or more depending upon the system

requirements the data detect output is valid 1.5 ms (2.5 ms worst case) after application

of the supply and is used to inhibit the power saving while data decoding is done.

Internal data slicer

A CMOS compatible data output is available on pin 7, this output is normally used to drive a digital

decoder IC or a microprocessor which is performing the data decoding. The data slicer in the receive

module is designed to accept data with a wide range of pulse widths and mark: space ratio’s, see

specification table for limiting values. The data slicer has a 10 ms transient response time this is the

settling time of the adaptive comparator, i.e. the first 10 ms of signal may be corrupt at the data output.

System coding

The transmit and receive modules have no internal digital coding/decoding thus allowing the flexibility

to send many types of data. Encoder and decoder IC’s are required to give the system a high degree of

protection from false triggers due to noise/interference/neighbouring systems and often for security

reasons. There are wide range of suitable encoder/decoder IC’s which may be used with the modules,

including :-

MM57C200, MM57410,National Semiconductor

UM3750, UMC

HT12 series, Holtek

MC145026 series, Motorola

AS2787, Austria Mikro Systeme International GmbH

Additionally IR. remote control, DTMF, Selcall and modem IC’s can be easily interfaced to the modules.

Radiometrix Ltd, SILRX-UHF Data Sheet page 9

AF output

This output is the FM demodulator’s output after buffering and filtering. Since it is taken before the

data slicer in the module, it may be used to drive external data slicers / demodulator’s in cases where

the internal data slicer is not suitable. This is the case where an analogue subcarrier is being employed

e.g. 2 tone AFSK or DTMF tones. In these cases the AF output is used to drive the FSK / DTMF decoder

directly.

The AF output is also a very useful test point for monitoring signals or interference. The AF output is

DC coupled to the FM demodulator thus the DC level Varies with the frequency of the incoming signal.

Supply requirements

The module requires a clean supply. Noise and ‘hash’ in the 5 to 500 kHz band and 16 MHz ±1 MHz

must be less than 2 mV, We recommend a 10 µF capacitor to ground on pin 5 (Vcc) and a 10Ω series feed

resistor in cases where the cleanness of the supply is in doubt.

Additional Reading

BS 0799 British standard for Wire-free intruder alarm systems

BS 4737 British standard for intruder alarm systems in buildings from British standards

institution - Tel. 44 171 629 900

MPT1340 DTI type approval specification for 418 MHz Telemetry from department of

Trade and Industry - 44 171 211 0502/0505

ARRL Handbook Excellent radio engineering text

ARRL Antenna Book Practical antenna design book

Warning: Don’t be tempted to adjust the trimmer on the module, it controls the receive

frequency and can only be correctly set-up with an accurate RF signal generator!

Radiometrix Ltd, SILRX-UHF Data Sheet page 10

Applications note

Four Channel Receiver with battery saver

Fig 7 shows a simple four channel paging receiver with 256 setable codes. The CMOS 555 timer

provides a duty cycle power save circuit which latches ON when a signal is present. The values used in

the example give 4ms ON; 400 ms OFF, i.e. 1:100 duty cycle. The total quiescent current is less than

200µA, thus a 9V alkaline battery (500 mA/hr) will give a life of over 2000 hours. The ON time is

determined by the receiver’s power up settling time (3 ms worst case) + any tolerance of the duty cycle

oscillator. The OFF time is controlled by R8 in the circuit and should be selected to suit the application

depending upon the required response time and any limits imposed upon the duration of the

transmission. It is recommended that the OFF time be no longer than 1/2 for the transmission

preamble duration.

Ordering information

SAW based OEM Transmit and Receive modules.

TXM-418-5 UK Transmitter on 418 MHz, Type approved to MPT1340

TXM-418-10 Fast transmitter on 418 MHz, Type approved to MPT1340

RXM-418-5 matching UK receiver module on 418 MHz

SILRX-418-5 Low current UK receiver module on 418 MHz

BiM-418-10 Bi-directional short range module on 418 MHz

RPC-418-5 Self-contained module wich integrates the BiM transceiver with a Radio Packet

Controller

EVAL-418-A Evaluation kit for TXM & RXM

EVAL-418-B SILRX supplementary PCB for EVAL-418-A

BiM-KIT Evaluation kit for BiM-UHF modules.

All modules are available in a 433.92 MHz version for use in other European countries.

figure 7: Four Channel Receiver with power save

Radiometrix Ltd

Hartcran House

Gibbs Couch

Watford

WD19 5EZ

ENGLAND

Tel: +44 (0)20 8428 1220

Fax: +44 (0)20 8428 1221

info@radiometrix.co.uk

www.radiometrix.co.uk

This product data sheet is the original work and copyrighted property of Radiometrix

Ltd. Reproduction in whole or in part must give clear acknowledgement to the