Frequently Asked Questions

Please see below a list of frequently asked questions and answers about GJD detectors and illuminators.

Detectors – General:

Q) What is the recommended mounting height for an external detector?

A) 3 metres is the optimum mounting height.

Q) Will they pick up vehicles?

A) Not always, depends on car temperature against background temperature.

Q) How can I avoid detecting small animals?

A) Use the flat beam mounting and masking option.

Q) Do you have external detectors that will ignore animals?

A) Yes when mounted at 1.5 metres with the bottom section of the lens masked off to form a flat beam pattern. Also with the lens module tilted up.

Q) What is the difference between a single PIR, twin PIR or dual technology detector?

A) The single PIR will trigger with a single detection in the beam pattern, the dual PIR will trigger when there is a detection on both sets of beams, and the Dualtech also needs the microwave to trigger along with both PIRs.

Q) What benefits does the microwave part of the detector give?

A) The microwave needs to see a physical moving object in addition to the PIR seeing moving heat.

Q) Which detectors are BS8418 compliant?

A) All the detectors in the D-TECT range are BS4818 compliant.

Q) Reasons for short ranging:

A) Incorrect angle of detector module, wrong range or pulse count programmed in, ground sloping towards or away requiring re-alignment, structure mounted to not truly vertical, or walking towards the detector rather than across the beams.

Q) How much current can detectors switch?

A) 25 mA on A and S outputs and 50 mA on relay contacts.

Q) The external detector gets full range without cover but is short ranging when cover is fitted?

A) The cover does reduce the detection range. Always walk test with the cover on. Check the range setting on the detector and the module position.

Q) Only getting about 1 metre of coverage?

A) Check the Fresnel lens is fitted.

Q) How many detectors can a receiver work with?

A) RFX Receiver will work with 3 detectors. D-TECT X Receiver will work with 4 detectors, but is expandable up to 16 using 3x 4 way Expander modules.

Q) The lens on my detector has fallen out – which way up does it go?

A) The vertical sections are to the bottom of the lens.

Wired Detector

Q) What type of cable can I use?

A) Detectors should be wired using multicore alarm cable.

Q) How do I put a Wired D-TECT into walk test?

A) Press the program button once and release, the blue LED will flash out the existing range setting. This enables the detection LED and output to trigger the Walk Tester.

Q) Can I daisy-chain the detectors?

A) Yes this can work, but would usually mean that there would not be individual indication as to which detector has been triggered.

Q) What is the difference between the D-TECT 2 and the D-TECT 3?

A) Both units are quad PIR with the D-TECT 3 having a microwave detector.

Q) Detectors are not always activating with cars?

A) As above

Wireless Detector

Q) How far will the RFX/D-Tect X transmit?

A) The maximum line of sight transmission for the RFX is 150 metres and 500 metres for the D-TECT X.

Q) Does it have to be in line of sight?

A) No, but any obstacle will reduce the transmission range depending on material. Always carry out a sight transmission test.

Q) How long will the batteries last?

A) Average battery life for the RFX is 2 years, for the D-TECT X is 1 year and D-TECT X MKIII is 2 years.

Q) How can I check the power level in the batteries?

A) Use a volt meter.

Q) How can I tell if a detector has linked to the receiver channel?

A) On the D-TECT X the channel LEDs flash alternatively when learnt and on the RFX there is a 2 tone audible sound.

Q) Does the receiver need to be outside?

A) Not necessarily, but any walls will reduce the transmission range.

Q) Is there an extension for the antenna or a way of boosting the RF signal?

A) No.

Lighting Control Systems

Q) How many Dygizones can I have on a system?

A) The maximum is 4 – 1 master and 3 slaves. Consideration should also be given to the 12 volts supply capacity and cable length.

Q) What components do I need as a minimum to make a DygiZone system work?

A) One 4 Zone Expansion Unit, one DygiZone keypad and GJD detectors.

Q) How many detectors can I have per zone?

A) No specific limit, there are 3 inputs for each zone, but detectors can be paralleled.

Q) What cabling do I need to use for detectors and DygiZone keypad?

A) The recommended is 8 core alarm cable.

Q) Can I adjust the volume and brightness on the Dygizone panel?

A) Yes, there is adjustment for both.

Q) Which detectors work with the lighting control systems?

A) Detectors with A and S outputs; which are Opal, Mini Opal, Elite, D-TECT 2, D-TECT 3, D-TECT 40, D-TECT 50, RFX range and all D-TECT X range.

Q) How do I put a Dygizone into walk test?

A) Press and hold the zone button for the zone to be tested on the master keypad until the engineer display is showing. Keep pressing the red button until the hand symbol is showing then press the up arrow. The walk test will cancel after 5 minutes.

Q) How do I put a Solitaire into walk test?

A) Select the green LED only on the zone to be tested on the master keypad then press and hold that zone button for 8 seconds until there is a beep then release. To cancel walk test press the zone button until all the LEDs are off.

Q) What is the difference between connections on an old Emerald 3000 and the Emerald MK3?

A) The A inputs were combined together for a zone and the S inputs were separate on the old Emerald 3000, on the new Emerald MK3 the A inputs are separate and the S inputs are combined together for a zone.

Q) Can Solitaire and Dygizone controllers be on the same system?

A) No they can’t be mixed.

Q) How much lighting load can controllers switch?

A) Each zone can switch up to 1,500 Watts of resistive load and up to 1,000 Watts of ballast driven lighting with suppression snubbers fitted.

Q) My lights are activating when it is light

A) Check that the zone and/or the detector are not programmed to 24hr. Cable faults to check for are shorts between ‘-‘ and S also between A and S.

Q) My Lights not activating when it is dark

A) Check that the Lux level is not set too low for the ambient lighting and that the S wire is intact and connected to the correct S input.

Q) My Dygizone won’t go into programming mode

A) This will happen if the DygiZone has no ‘M’ symbol showing. Power the system down, remove the battery wait 30 seconds then re-apply the power.

Q) Are the new Opals compatible with the old Opals?

A) Yes, they both have the A and S outputs, they may be in a different order.

Q) Can Active Beams be connected to a lighting controller?

A) They can, but will need an additional photocell with volt free contact to control the day / night function. GJD Multiswitch can provide this function.

Q) Why does my Dygizone keypad no longer respond when it has a picture of a spanner on it?

A) The keypad is locked, press and hold zone 1 and zone 4 buttons together until a beep sounds to unlock.


Q) How many speakers can you have on a Multispeech 4?

A) The maximum is 2 but the total resistance should always be 8 ohms. The more speakers fitted the lower the volume.

Q) Do repeaters need to learn detector codes?

A) No, they recognise the codes automatically.

Q) Detector won’t learn on to the receiver

A) Check the channel does not already have a detector learnt on to it.

Q) The GJD970 beams will not settle at 1.5V as per the instructions

A) This can happen if the beams are not correctly aligned or the mounting surface is not secure.

Q) Why does my continuity tester not show me normally open or closed contacts properly?

A) All detector contacts have a series resistor built in; which stops continuity testers working correctly, it is always best to use an ohms reading.

GSM Dialler

Q) What size of SIM card is used?

A) The SIM card is the standard type. (NOT the micro or Nano)

Q) How long is the recorded message?

A) 3 second ‘dead’ time then a 10 second recorded message that can be shortened (when it is being recorded) by pressing the ‘ENTER’ key. Total 13 seconds repeated upon dial out 3 times, unless cancelled by the recipient pressing either * or # key on his telephone keypad.  If call not answered or cancelled, the dialer will then call the next number in turn and start repeating the message

Q) Which networks do they work on?

A) All, apart from the ‘3’ network

Q) Can you use text?

A) Yes, you can have voice and/or SMS

Q) Can you use PAYG and contract SIMs?

A) Yes, you can use both

Q) What happens when credit runs low?

A) You will have to top up the SIM card. If the network sends out a low credit warning, that can be forwarded onto the first number provided that the option “call forwarding” is set as ON (call forwarding is set as ON as default setting)

Q) How do you keep the SIM active so it doesn’t switch off?

A) Manually trigger the unit monthly, or set up a test call/message.  Note some service providers require voice rather than data to keep a SIM card enabled

Q) How many numbers does it dial?

A) It can call up to 9 different numbers

Q) Can you extend the aerial?

A) Yes, but you will have to outsource the equipment. The connector is an SMA connector

Q) Has it got battery back up?

A) Yes. 9V (PP3). Approximately 2 hrs back up (assuming no dial out)

Q) Which alarm panels can it connect to?

A) Most alarm panels. The dialler requires the trigger(s) to be shorted to a common 0V in order to trigger the dialler

Q) Does it have PSTN input as well?

A) No, only GSM.

Q) How many times will it ring a number?

A) Once, factory default. It can be programmed to ring each number 3 times.

Q) How many text messages will it send before sending to the next number?

A) One per number (repeated up to 3 times), you can specify which numbers can receive SMS and/or voice

Q) How many times will it sequence through the numbers looking for a response before it stops dialing?

A) Once

Q) What power supply does it need?

A) 12VDC. Best if powered from the alarm system.  Power supply must be 12V regulated

Q) Does it need a laptop to program?

A) No all programming is done on the unit via the keypad.