Expansion card startup questions

[gatchel]

This is interesting. I added a 212, a XIN, and an XOVR to my detached garage a few months ago and remember having some gremlins as far as getting the XIN or the XOVR online. I can't remember exactly the scenario but I remember rebooting the control which I think resolved my issues. It''s been rock solid ever since.

 

[Ira]

Finally got around to this again. The original problem (XIN restarting) hasn't happened again. However, on Friday, a different XIN kept reporting a different problem (lost communication, followed by communication restored less than a minute later). This happened about every 15 to 30 minutes. This XIN is connected to the 3rd DBH in the chain (the other XIN is connected to the 4th DBH). This DBH is about 60' (wire distance) from the first DBH which is in the same can as M1G. Since I don't need that XIN for now (it's part of an irrigation control system that is not used this time of the year), I unplugged it to silence the notfications.

So this morning, I got a lost communication notification from an XOVR that is mounted in the same remote can as the original XIN that had a problem (both on the 4th DBH). A few hours later, it still hadn't restored communications. When I checked it, the LED was flashing two flashes. I unplugged it from the DBH for a few seconds, then plugged it back in. After a minute or so, the LED started showing the normal single flashes, and it hasn't lost communications yet.

I also checked the voltage at the 4th (most remote) DBH. This is the one with the terminating jack installed. Voltage was 12.22Vdc. My multi-meter is a pretty cheap one, but it seems pretty accurate when testing various wall warts, power supplies, etc.

 

[Del91574]

I'd give Elk engineering a call, but I believe that is lower than what is recommended.

 

[Ira]

Back at this again...

Due to some other stuff I'm doing, I've decided to implement "distributed power supplies" this weekend. To start with, I will be using the Elk P412 I already have in my 2nd can (1st remote can) to power the expanders in that can and the 3rd/next can located about 15' away (length of wire). I will add some type of PS (not sure which one yet) to the 4th/furthest can (the one located 200' away).

So given that each of these cans has a DBH, and power is currently being provided "thru" the DBH's from the main can, and if I want to keep the common ground intact throughout the entire system, it sounds like what I need to do is...

1. Clip the brown/white wire (shown as the + conductor in the DBH documentation diagram) at one or both ends of the cable going between the DBH's if I don't want the power to be supplied via the previous DBH. So I would clip that wire on the cable going from the 1st DBH (in my main/1st can) to the 2nd DBH because I want the expanders connected to the 2nd DBH to be powered by the PS in that can. I don't clip the brown/white wire on the cable between the 2nd DBH and 3rd DBH because I want the expanders connected to the 3rd DBH to be powered by the PS in the 2nd can thru the 2nd DBH. Finally, I would clip the brown/white wire going from the 3rd DBH to the 4th DBH because I will have a PS in the can that contains the 4th DBH.

2. In each remote can with a PS (2nd and 4th), connect the PS to the + and - terminals on the DBH's terminal block. That will then provide power thru the cat5/RJ45 connections on the DBH to the expanders in that can, and to the next DBH if the brown/white wire isn't clipped. Also, by keeping the white/brown wire in the cat5 between all DBH's intact, I've still got a common ground across all cans, expanders, etc.

Am I missing anything?

Thanks,
Ira

 

[Del91574]

Since I don't use DBH's (only DBHR's when needed) I'll paraphrase with no reference to colors/pinouts. Your basic premise is correct, however you will need to make the additonal supplies common negative with your panel, meaning their negative will need to be connected to the panel's COM.

Refer to page 67 of the latest revision of the M1 manual. I'm sure earlier revisions have a similar page #.