M1DBH best practices....

Im thinking of using the M1DBH in my setup...its not really required (I only have 3 items on the databus) but would prefer the neater/easier wiring.

A question - Ive always been taught that you dont want in-wall (solid conductor) Cat5E connected directly to something via a connector pressed on the end. You always want a patch panel in between, so the in-wall stuff stays in one place, no chance of moving around and breaking.

How does this apply to a DBH install? Does everyone just crimp an end onto the incoming Cat5? Or do you use a mini patch panel inside (or outside) the alarm can, and then short patch cables from the panel to the DBH?

Im not quite grasping the advantage of the DBH other than the neater wiring, and it makes me wonder if the DBH is really that advantageous all things considered.

I can't comment on what is right, but I just crimp the RJ45 on the connector, bring it into the panel and plug it in. An alarm panel is not exactly an actively changing environment with a lot of motion.

I was delighted with mine, I ended up with about twice the number of data bus devices I anticipated and it was very nice to just run RJ45 into one thing. Was it necessary? I could have daisy chained it all together. But it sure was nice. I ended up with seven. You will also, just wait. They multiply when you are not looking.

FYI...they make crimps specifically designed for solid - I've used them all over the house for years and never had an issue.
What I did though since I only have 2 remote databus items is ran stranded and crimped that. If I had more I'd consider running solid to a small patch panel in the enclosure. I'm used to running solid to a patch panel, but also had a spool of stranded doing nothing for years so I used it.

Come to think of it, my XEP is connected directly via solid since that runs to a patch panel in my A/V closet which, unfortunately, is on the other side of the house.

I would call the DBH and peripherals permanent wiring, really not subject to the moves/changes that a lot of IT folk seem to be thinking is the norm. Even the bulk of most of the enterprise networks I work on maintain solid as a patch cable.

I believe what the reference is as far as a patch panel being used for is a point where the permanent (hopefully) field wiring is connected to the permanent hardware, but still allowing for moves/changes as needed.

I chose to terminate the solid-conductor house lines and use stranded patch cables to the hub. In some cases, such as the keypad on a nightstand which is plugged onto a structured wiring jack behind the bed, the patch cable to the hub plugs into the main patch panel near the Elk. For devices mounted in walls, I terminated the Cat5e cables in a mini panel consisting of a surface mount box with keystone jacks.

Thanks.

Photon hit exactly on what I was talking about....permanent "house" wiring going to a patch panel before being plugged into the DBH.

I already have a large (with lots of empty ports) patch panel for my house network....Im debating punching down the security stuff to that and then patch cable into the Elk can, or getting a mini vertical patch panel to put inside the Elk can, so all of the security stuff is contained. Either way I think patch panel before DBH is the route I will go.

If you decide to punch down I would either use a small surface-mounted patch or a keystone box, like Photon, INSIDE the enclosure.

The only issue I can see is maintaining the pinout for 568A and the related devices.

I can't say I'd see the benefit or extra effort paying off, why make it more complex than it needs to be. As they say KISS.

I think KISS would be not using the DBH at all, but I just dont think B-connectors hanging around are a neat way to wire everything. Easy enough to add to, OK enough to remove from, but not nearly as plug and play as the DBH.

Maybe Ill just leave a service loop on the CAT5 cables and terminate them directly into the DBH. If I ever feel its an issue I will have enough CAT5 in the loop to rearrange and add a patch panel.

chrisexv6 said:

I think KISS would be not using the DBH at all, but I just dont think B-connectors hanging around are a neat way to wire everything.

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I agree. I believe the DBH is "cheating" per say. I am fortunate to have access to most of my wiring from specific locations in my house. I have a 22/2pr cable to each device and from each device to the next. There are no B connectors on the data bus except at the KP splices. Besides, If panel real estate is of any value to you then you can gain more by not using the DBH. IMHO of course, I'm sure the "not using the DBH is stupid" comments are sure to come. You have to do what works for you. If in your mind you need a patch panel (or 3) in line before the DBH then have at it.

A service loop would be the way to go IMO.

I see it as this, not a bash or flame to any parties involved. I'm not referring to a DBHR, which is another entity and topology altogether.

A DBH is just a patch point for the field wiring. IMO,the only thing it does is makes easy for someone not familiar with 485 topologies to connect multiple devices and maintain the proper daisy chain and termination with the caveat of increasing the likelyhood for a bad termination/RJ45 crimp.

The one item I don't like is on many installs, where installing a secondary supply like a 212S (instead of a larger supply and tying supervisiory outputs to the panel) the DBH makes it far more difficult to spread the load to auxilliary supplies, especially when lots of bus devices are involved, now you're looking at not terminating a conductor in the RJ45, on top (if used at the panel) a conductor or two for the output and input the keypad provides. I may be a minority here, but that doesn't seem like it ends up saving work or make for a better install if I need to break out wiring at the panel just to gain access to the KP outputs or inputs.

I think, unfortunately, the engineers and Elk missed the boat on the design of the DBH by not considering the possibility that the KP outputs/inputs may be brought back to the panel and used for items remote from the keypads themselves in addition to the power considerations, unless you install a 212S in the bus between the panel and the DBH to negate the panel seeing any load from the bus devices.

DELInstallations said:

I think, unfortunately, the engineers and Elk missed the boat on the design of the DBH by not considering the possibility that the KP outputs/inputs may be brought back to the panel and used for items remote from the keypads themselves in addition to the power considerations, unless you install a 212S in the bus between the panel and the DBH to negate the panel seeing any load from the bus devices.

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This would be an easy re-design for them (I'm not considering PCB redesign costs and toolling...) and I agree 100%. They could have a simple 3 pin shorting jumper related to each DBH RJ-45 port. Position A would select Elk M1 power, position B would select an Aux 12vdc power supply wired to a separate terminal strip. They could even have a jumper to common the negatives of the two supplies..

The use of the extra pair in the cable coming back from the KP's, simple to fix too...

DBHR's... I'm glad we don't see too many posts here about them.

gatchel said:

This would be an easy re-design for them (I'm not considering PCB redesign costs and toolling...) and I agree 100%. They could have a simple 3 pin shorting jumper related to each DBH RJ-45 port. Position A would select Elk M1 power, position B would select an Aux 12vdc power supply wired to a separate terminal strip. They could even have a jumper to common the negatives of the two supplies..
The use of the extra pair in the cable coming back from the KP's, simple to fix too...
DBHR's... I'm glad we don't see too many posts here about them.

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I don't mind the DBHR's, with the exception that you need to have 2 branches installed and terminated on each port, otherwise you can't cascade the 485 to the next port, basically just missing in the documentation. Threw me on a conversion once when I tried to land a single 485 branch per port.

As far as improving the DBH, I'd ask for a terminal block or two underneath to connect the inputs/outputs to, and really pushing would be a second terminal strip and dipswitches to enable/disable power from the panel connecting to the devices on the DBH. I'm content with the terminal block for the panel feed, since I'd rather use standard wiring instead of premade plugs or being forced to crimp ends, to cascade from the panel into a 212S, drop the panel's +12V on the dummy terminal, then into the DBH with the 212S power, and if dipswitches were used, cascading into another hub would be easy since power could be kept from carrying through to the next 212S/DBH combo.

I doubt Elk will do much in regards to the DBH, since they're passive and frankly, cheap items. I'm still trying to push for them to either do multiple 2 wire fire zones or integrate some sort of SLC for the fire alarm via a inputt/output card, however that would also make tandem ring almost impossible.

I agree with the suggestion for separate power inputs, and also why not just have a punch down block as an alternate connection for each jack. That wouldnt be an expensive fix, heck Leviton already makes something like that and its pretty cheap.

I know I could just daisy chain everything "in the field" but I think that just leaves too much work if I ever wanted to expand.

I suppose instead of B-connectors I could use terminal blocks to screw everything down, still doesnt seem to be the best way to do it though

If you want punch-down connections, the option to easily drive the connected devices from different power supplies, and easy access to the keypads' input/outport ports, how about using a 66-block instead of the hub?