ELK M1 - Multiple Data Bus Runs

Hello Guys:


I have an ELK M1 system. I replaced an ADT system last year, so much of the wiring was in place.

I have a 6000sq. ft. shop about 800ft from the main house. Because I house my motorcoach, tools, toys, etc. - I decided to tie that building into my home security system. There was already a 10 conductor run from the house to the building already (how lucky is that??) - I used 2 wires for the siren, 2 wires for a data connection (VDSL from the house to the shop over copper), 4 for the databus connection - that leaves 2 free if needed.

I already had 2 runs tied into the databus on the ELK control -- one line (4 conductor) went to 2 in-series keypads. The second went to the GE wireless receiver. I added the third to the shop and at the other end I have a zone expander and then that line terminates with the keypad out there.

After doing all of this, I noted in the manual that there should be no more than 2 "homeruns" from the databus without a hub. I looked into the hub and I cannot, without serious drama, replace the 4 conductor wire with cat5 for the 2 existing keypads. The GE wireless receiver is connected via CAT5 so that would not be a problem, however. I could, as an alternative to the hub, daisychain the shop after the GE wireless receiver, so there would only be 2 homeruns - though I don't see what difference it makes.

As of right now - everything is working perfectly -- 1 line for 2 keypads, 1 line for the GE receiver and 1 line for the shop (M1XIN + Keypad.) Area 1 (house) communicates with its keypads and wireless zones just fine and Area 2 (shop) communicates with its keypad and zones fine.

Is this a could have problems down the line scenario, or if it works, it will continue to work? If the former, are there any suggestions for correcting the situation without tearing holes in walls and running new wiring?


Thanks for all of your help, as always!

They make the DBHR which is designed to give 4 separate "Legs" - that could be an option; requires only 4 wires instead of 6.

I'd pay attention to the error count and see how it's doing - if it's working reliably, then you might be OK.

Make sure you're protected against surges and have a separate power supply for the shop - that kind of distance and running more devices, you're asking for voltage-drop issues.

The DBHR is exactly what I was looking for. Thank you VERY much!!

Couldn't you just run a wire from the wireless receiver back out to the remote building? If it were me I would avoid the DBHR, JMHO...

No, unfortunately. The whole building is surrounded by asphalt -- I'd have to go under about 80ft. of asphalt (in addition to the other obstacles such as an irrigation system, pet fence wiring, etc)

As mentioned, I already have the wire in place that was put in when the building was built. That's how it's connected now. It terminates at the Elk control right now, but the wireless receiver is only 20-30 ft. from that, so it's not outside of the realm of possibility to piggyback on the wireless receiver. What is the difference between tapping it directly at the wireless receiver vs how I'm doing now (at the control?)

I ordered the DBHR earlier -- is it unreliable?

Thus far, my current setup has no errors, but I would prefer to err on the side of caution.

As an aside - someone mentioned putting power in the shop for the modules out there. Is there information on how that's accomplished?

Thanks again.

That's what I meant...outside building to wireless receiver....then to elk panel. Still only 2 data busses from the elk and a proper elk RS485 daisy chain as long as you terminate correctly.
As mentioned my others and myself in other posts, surge protection is a really good idea.

Add a P212S in the shop. Use it's power terminals to supply power to the shop devices. Then, from the cable coming in from the house, use 1 twisted pair cable for data (RS495 Bus) and use another conductor to tie the elk panel power supply negative (Data bus negative) to the remote P212S power supply Negative terminal.

The 212 is nice because is can be supervised by the elk and it handles a battery backup too...

The retro hubs work fine with multiple star runs. We use them quite often because of the retrofit market in my area. In my case, I ripped out a Honeywell Vista panel for the M1, so I'm running multiple units with no foul involved, no errors on the bus either.

In the case of what to do, the big item to contend with here is total length, which would come into play irregardless. I don't know if I'd recommend a partial rewire as the DBHR's allow up to 4000' total length for any of the branches, instead of the same value total on the M1.

I would, however, install a supply out at the detached building, common to the panel, and drive the hardware out there off it. Make sure it had 0V drop when it runs on battery only. M1's do not like when the voltage at devices sag to 12V or lower. Wiring diagrams to do this are on the DBHR's install instructions. Very easy.

You guys are great, thanks! I'll heed the advice and put a new power supply out there. I've already ordered the DBHR, so I'll put that in for good measure as well.

Any advice for a siren in the detached building, bearing in mind that I assume I would only be able to use the existing line for a trigger of sorts?

Thanks again!

For a Siren, you have two good options.

1. If you have a use for any other triggers (garage door openers, contact closures of any sort, strobe lights, water shutoff, etc), then it might be worth it to have a M1XOVR board out there - that'll give you 8 relays and 8 voltage-only contacts (which can be converted to 8 more relays with an M1RB later if desired). With this, you'll have plenty of outputs to be able to hook a siren to 12V (via the new power supply) controlled via rules.
2. If you really don't want the zone expander because you have no need for more outputs, every keypad has an input and an output that can be wired directly off of it - it's not enough to drive a siren, but it can drive a relay (like in option 1) to also drive a siren by rules. Check the manual for specifics, but this is perfectly doable.

As was alluded to in an earlier post.....surge each end of the data bus, connect to ground with a cable shorter in distance than the "protected" side connecting to the equipment.