Visonic MC 308 with Comfort II

[cc_uk]

I have a Comfort II with a Visconic MC308 connected to it.
I have two Visonic wireless PIRs - one is currently paired with the MC308.   I am getting spurious false alarms on the Comfort system.
The PIR is fairly close to the MC308 so it\'s not a range issue.  The PIR is in a closed box while I am testing,  so not triggering it\'s sensor.
I have additionally removed the cover from the MC308 to put it into test mode.   When the spurious alarms are received by Comfort they do not correspond with  a PIR trigger to the MC308 (ie no success tone fropm the MC308).

I do hear the \'success tone\' from the MC308 every 10-12 minutes which I believe is a keepalive between the PIR and the MC308  These do not trigger a comfort alarm.
If I deliberately trigger the PIR I do get the success tone from the MC308 in test mode and Comfort does also trigger.

Therefore I believe the problem with spurious alarms lies between the MC308 and comfort
Comfort is configured with shunts not to require EOL resistors, and no EOL resistors are connected.  There are three connections between comfort and the MC308 - 12V, 0V and Zone 1 on MC308 connected to Zone 4 input on the Comfort panel.
There is no connection to COM terminal on the comfort panel, for this zone, but I assume all the COM zone connections are tied to 0V anyway.  And no connection to COM on the MC308
The Zone on Comfort is configured as a NC.  I have tried with Digtial set to YES and to NO and Sensitivity values of 100, 200, 300, 400 & 500 and get the same result.
Shoudl this open collectior type connection be defined as Digital or not?    What does that setting actually do on Comfort?

Any help appreciated.

[slychiu]

I believe the MC308 outputs should be relay, not open-collector. Open-collector outputs connected to Comfort Input do not pull to ground, the worry is that they may not trigger the activation of the zone. However that would cause zone troubles not false alarms.

Digital N/O and N/C zone types do not have Zone Trouble, and allow a wider range of voltage for on and off.

One possibility is that there is a fault on the MC308 outputs which trigger wrongly, or there may be a wiring problem between MC308 and Comfort zone.

However I think it is more likely that the false alarms are due to of the PIRs actually detecting something moving, or insects, warm air etc. Try  changing the positioning of the PIR

[cc_uk]

Thank you for this. I know for sure that nothign is triggering the PIR at the moment - as it is new, out of it\'s box for the first time, so no insects in it etc. Also I have put it into a closed box to ensure it does not trigger.

When the MC308 is put into test mode, it makes a sound when the PIR does trigger, and I hear no sound from the MC308 when Comfort detects an alarm condition.

DO you mean I shoudl add the relay board to the MC308 and use that? Earlier posts here suggested it is OK to connect the MC308 directly to the Comfort panel as the MC308 uses open collector outputs.

The wiring has been checked out & is OK and connected as follows:

MC 308   -   Comfort
12V  -  12V
0V   -  0V
Zone 1  -  Zone 4

[slychiu]

Open collector Output should be OK if the voltage is less than 1 Volt when On.

Check the voltage at the zone when the PIR is not detecting and when the PIR is detecting.

After that, short the PIR Output at the PIR, and wait to see if any false alarms are detected in Comfort. I dont know how often there is false alarms, but wait for a much longer time to confirm. If there are still false alarms then there is a problem with the wiring, or the Comfort zone. If there are none, tgen the IR itself is generating flase triggers - this last outcome  is more likely