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Senior Member
I recently setup 2-wire smoke detectors (4 System Sensor i3 2WTA-B to start). All properly flash a green light every 5 seconds.

I wired them to the elk, going from the panel, to a reversing relay (RRS-MOD).

I tested a detector and it worked, but it did not work properly to set off the other detectors on the circuit.

I suspect I may be misinterpreting how the Elk rules should work.

I setup rules like the following:

THEN TURN Output 003 (Out 3) ON
THEN TURN Output 003 (Out 3) OFF

One wire of the RRS-MOD goes to the NO side of Out 3 (so that when Out 3 is triggered it reverses the polarity).

When I did the test and checked the log I got

Zone 16 is defined as 10 - Fire Alarm, 2-wire smoke on zone 16.

Output 2 is hooked up to a siren.

I see that the OUTPUT2 SUPERVISORY TROUBLE message is because I omitted a resistor (I'll fix that).

My question really boils down to (and sorry for the basic questions, just trying to establish what I should be expecting and where to troubleshoot):
1. Should I see Out 3 triggered in the log or not? (I was assuming yes)
2. I'm assuming that 1001 FIRE ALARM, satisfies the condition of 'ANY FIRE ALARM'

On a side note, I have a request into System Sensor on if there are any preferred installation orders when using both a 2W-MOD2 and an RRS-MOD (may be no issue at all, but was looking to make sure one can't impact the other in any configuration (Panel -> 2W-MOD2 -> RRS-MOD -> Smokes or Panel -> RRS-MOD -> 2W-MOD2 - > Smokes). Due to what the RRS-MOD does, I am assuming preferred order of installation is Panel - 2W-MOD2 - RRS-MOD - Smokes). Once I get the answer I'll post it here.


Senior Member

I have the same detectors but I did not hook up the RRS-MOD yet although it is sitting here. I'm sure you have this right but just to state the obvious - are you sure JP1 is to the right '2wire smoke vs normal'? Thats all I can think of but since the 1 detector works you probably have it right.If I get it working in the next few days I'll post it here.


Senior Member
Ok, well you inspired me to just get it done. So I just hooked it up and unfortunately have the same results as you do. The one I trip sounds but not the other. Maybe David has some suggestion otherwise we will need to talk to System Sensor next week.

I essentially have mine wired like Figure 3.2 (Doc here).

Red - S Aux +
Black - S Aux -
Yellow - Zone 16 + on panel
Orange - Zone 16 common on panel
Brown - To detectors +
White - To detectors -
Purple - Output 16 N/O (On M1RB board, my Out 3 is to strobe)
Jumper wire from S Aux + to Output 16 common

I have tried it with the switch on the RRS-MOD in both settings.

I added rules just like yours and know they work as my Output 16 LED comes on during alarm and off when acknowledged.

The only thing I can think of is maybe we need a resistor like shown for the Ademco or DSC panels like Figure 6? Thats my guess but not going to try till we get Davids or SS's opinion.


Senior Member
Output triggers are not logged. ie. just turning an output on or off does not go to the log. Generally an alarm condition is written to log.

One thing to check on Output 2. If you are going to a siren driver that drives a speaker, either self contained or remote you need to set the Output 2 drive output to voltage. That is probably why you are seeing a supervisory trouble on output 2 when the alarm goes off.

I take it that you are reversing the current on the smoke detectors to make them all sound with the RRS-MOD module. Your Rule looks OK. You are turning on Output 3 when the fire alarm activates and turning it off when the alarm turns off. Check to see that Output 3 is working properly. Just look at the LED next to it on the M1 board. Measure the polarity of the voltage before and after the alarm activates at the smoke detectors or at least the wire going to the smoke detectors. You should see the voltage polarity reverse when the alarm activates.


Senior Member
Steve, I verified this is set properly. The jumper is to the right and set to 2 wire smokes.

I forgot about the LED on the board for OUT3, great point. I think I better understand how the log works. I'll rerun the test and confirm that it is working properly, but it looks like Steve set it exactly the same way I did, except he used an output board, and I used OUT3 on the main board.

Spanky, you were dead on on Output 2. I missed that. I adjusted the setting and will include it in the test tomorrow.

I'll check further tomorrow. Thanks for the feedback.

I am glad I didnt try to get both the RRS-MOD and the 2W-MOD2 working at the same time (seemed like too many things to blame a mistake on until it was working with only one of them).


Senior Member
I've got some test results but admittedly they do not make too much sense to me.

First, the DIP switch on the RRS-MOD needs to be on for the relay to do anything.

Ok, so with everything hooked up and normal I measure +13.7V at SAux and +12.04V at both input (on Zone16 terminal) and output (wires to smokes). Weird is that Output 16 also shows +13.7V (only with relay connected, it is 0 with relay disconnected). Anyway, when alarm trips you can hear the relay cycling back and forth or on and off but the voltage measurement on input and output both change to around +6.8V. The output does not change polarity even though the relay is cycling. I also just tested where I did not trip the alarm but just turned Output 16 on. When I do just that, the voltage stays at +13V but the relay does cycle.

So I am stumped - why does the voltage drop to approx +7V on alarm? Why does the polarity not reverse? I triple checked all connections, verified proper functioning of the output? Strange is that the Output has 0V when off as expected with relay disconnected, but when you attach the relay Output 16 then has +13.

Hopefully this will make some sense to David or System Sensor tech support.


Senior Member
Ok, so with everything hooked up and normal I measure +13.7V at SAux and +12.04V at both input (on Zone16 terminal) and output (wires to smokes). Weird is that Output 16 also shows +13.7V (only with relay connected, it is 0 with relay disconnected).

This is probably due to a voltage feed back from the RRS-MOD module. Try disconnecting the wire from Output 16 and see if there is voltage on the RRS-MOD module side and not on the M1 Output 16 side. This should not be a problem anyway, just looks weird.

So I am stumped - why does the voltage drop to approx +7V on alarm? Why does the polarity not reverse? I triple checked all connections, verified proper functioning of the output?

One test to try is to take out the RRS-MOD and apply reverse polarity to the smokes to see if they all go into alarm.

The voltage is dropping because of the two wire smoke circuit. The detectors draw more current then they go into alarm, therefore causing a voltage drop on the two wire smoke line. According to the wiring diagram for the smokes, when the polarity reverses, additional current should be applied to the smokes to run the alarms. Somehow the reversing relay is not doing its job on the RRS-MOD.

Edited thought: Check the voltage inputs that feed to the reversing relay contacts. This should be from the SAUX power and make sure the polarity is not reversed on those leads. If the leads are reversed, when the alarm goes off, the voltage to the smokes would reverse again and would be NORMAL and not cause the smokes to go into alarm.


Senior Member
Not yet, been rather busy lately. I got the wiring diagrams for the 2W-MOD2 & the RRS-MOD together from System Sensor (which I'm not sure if you were going to do the same) and was going to use that setup for the next round (since it is where I was trying to get to anyway). I suspect this will change the landscape a bit, but I will post my results.

I'll see about getting this setup. If not during the week I should have some results by the weekend.


Active Member
I just went through this with a customer putting in 8 sensors to 8 zones and wanted them all to fire if one fires.

Here's the little bit System Sensor told me.

You need an RRS-MOD and an EOLR-1

The EOLR-1 is to supervise power.

Nice RRS-MOD wiring diagram in this PDF

Here's the wiring instructions for the EOLR-1

Perhaps this additional info helps pull something together for you?


Senior Member
You need an RRS-MOD and an EOLR-1

The EOLR-1 is to supervise power.

I always thought the EOLR was only needed for 4 wire detectors. I went back and looked at an old thread which verifies this:

All Four wire smokes do not need a reversing relay to activate internal sounders, although they do require End of Line Relays in order to supervise power through to the last detector at the End of Line. For integral sounders, four wire detectors are a better choice. Some use a 5th or 5th & 6th Conductor.

Two wire detectors, if equipped with integral sounders can use the reverse polarity method to activate sounders, but you need to ensure that the detector model is listed for use with the control and that the control does in fact support the reverse polarity feature. Make a mistake here and you might experience a failure at a critical moment.

As stated previously most jurisdictions require integral sounders and require all of the sounders to be "linked".



Edit: If the panel does not support polarity reversal of the powered circuit in a alarm, there are optional relays that can be added.

It would really stink to have to put BOTH relays. At that point I might as well have put in 4 wire detectors and used any zone I wanted. Are you sure SS said this for 2 wire detrectors?


Senior Member
From the diagrams, it looks like I may have to wire the 2W-MOD2 as a 4-wire smoke (thus getting a 2-wire zone for 'free', granted if not on the same zone its not going to trip the relay).

I originally thought this was not the case, which to a degree makes sense. If you have 2 wire smokes, why would you buy a unit to relay the clean me signal? It is when using it for this unusual circumstance that I suspect I will wind up using it's 4-wire to 2-wire conversion.

Those diagrams however don't show an EOL relay (I'll go back and check, but I am pretty sure they didn't).

I am also starting to wish I understood more earlier as I might have taken a different route (such as 4-wire) myself. Regardless, being too late for that, hopefully I'll have some results this weekend.

I've been meaning to play with this, to figure out the right way to do it, just incovnenient to test when I get home late.


Senior Member
OK I have this in, although I have not tested the reversing relay (wife would not appreciate that at the moment). I setup the following:

Elk M1 Gold -> 2W-MOD2 -> RRS-MOD -> 2-wire smokes

Now, it was correct that I needed to wire the 2W-MOD2 as a 4-wire smoke. I piped the cleaning signal to input 1 and the fire signal (as a 4-wire smoke) to input 2.

The other RRS-MOD connections remained the same.

There is a test on the 2W-MOD2 in that the green light is blinking, which signifies it is communicating with detector(s).

I'll try to see if the reversing relay is working now that I made this change.

Oh, I had to replace the EOL resistor at the last detector (which comes with 2W-MOD2, think it was 3.9K). The diagrams were right, since the RRS-MOD/2W-MOD2 is in between the panel and the smokes, it is the 2W-MOD2 which is dictating the right resistor (as it is the 2W-MOD2 which is notifying the panel of a short).

Inside the 2W-MOD2 however, there are 2 standard (elk-standard) EOL resistors).

If the reversing relay works I'll try to document the setup if it is helpful to anyone else here. If not, I'll have a little more research.


Senior Member
OK, I ran the test. The reversing relay worked.

However, it seems something may still not be quite right. Here is what happens:

1. All alarms go off (expected)
2. Output3 light on the M1G is on (expected)
3. Alarm speaker is clicking every second or so (not a normal alarm tone, but sounds like a hard click). (not expected)
4. The 2W-MOD2 has green light blinking (expected)
5. The 2W-MOD2 has red light blinking (not-expected as this should be solid to mean one or more detectors in alarm condition. blinking means one or more out of sensitivity or in freeze condition).
6. The 2W-MOD2 has a solid yellow light (not-expected, this references a loop wiring fault.
7. The above are when it is in alarm, when the 2W-MOD2 is not in alarm the green light blinks (meaning it is communicating with detectors).

There are no log entries other than the fire ones in the M1G (referencing any other problem).

It could be the reversing relay is throwing things off from the perspective of the indicator lights. The detectors are going off together. The only other strange item is the sound from the Elk speaker (the clicking).

I'll see if I can get any information on this, but if anyone has any thoughts, please let me know.