System for new house
- Thread starter bwarren
- Start date
tmbrown97
Senior Member
it's safe to say that DEL has never been a fan of the DBH, but I think most others around here use it just because it does simplify the connections, future expansion, and troubleshooting. Part of that probably comes from the fact that pro-installed system don't change as much as DIY systems installed by tinkerers who are ever expanding their systems... no doubt expansion is much easier with one, as is troubleshooting if something doesn't work.
Either way will function - just a matter of personal preference.
Either way will function - just a matter of personal preference.
drvnbysound
Senior Member
+1. I don't know that I'd install an Elk system without a DBH 
The issues I have with a DBH is they don't allow you to loadshed your power distribution for the keypad bus devices....1A on the M1 isn't that many keypads/XOVR's/expanders.
The second issue is they don't allow easy connectivity to the input and output that reside at the KP.
Third, is if you loadshed the power, input and/or outputs....have you ever tried to make reliable RJ45's while skipping pins in the plug? Compound that with a tinkerer that most likely hasn't made a lot of RJ's, well you're going to get into issues, or a mis-pin and then how much time is spent trying to diagnose or worse, something gets cooked.
If you have enough conductors run to the keypads or bus devices, it's a non-issue. You can even wire the bus to carry back no different than if you had a DBH, the only difference is the last unit's DATA A/B would need a 120 ohm resistor installed, which negates the terminating jumper necessity in the field.
I've had to help a bunch of DIY and novices troubleshoot their installs and guess where the problems were 9/10 times. I'll take a hard crimped connection before pulling to a DBH any day. (not referring to the DBHR's)
The second issue is they don't allow easy connectivity to the input and output that reside at the KP.
Third, is if you loadshed the power, input and/or outputs....have you ever tried to make reliable RJ45's while skipping pins in the plug? Compound that with a tinkerer that most likely hasn't made a lot of RJ's, well you're going to get into issues, or a mis-pin and then how much time is spent trying to diagnose or worse, something gets cooked.
If you have enough conductors run to the keypads or bus devices, it's a non-issue. You can even wire the bus to carry back no different than if you had a DBH, the only difference is the last unit's DATA A/B would need a 120 ohm resistor installed, which negates the terminating jumper necessity in the field.
I've had to help a bunch of DIY and novices troubleshoot their installs and guess where the problems were 9/10 times. I'll take a hard crimped connection before pulling to a DBH any day. (not referring to the DBHR's)
drvnbysound
Senior Member
Understood.
Fortunately for me, I haven't [yet] done anything larger than 30-ish zones, and 3 keypads; soon to do one with 4. I've also not yet used a keypad input or output, but rather have home run everything to the Elk or XIN. I've also placed SP12F's at each keypad, to which I've run 18/2 anyway. So, if there is an existing 22/4 in place, I've just used that as a sacrifical pull cord to pull a Cat5E and 18/2.
I also do a fair amount of RJ-45 terminations, which makes using the DBH simple [for me]. If I have to troubleshoot a device, I've literally unplugged the working devices, moved the RJ-45 terminating resistor, and troubleshot the individual device on the DBH - just very easy to do without having to do anything with crimped connections.
Fortunately for me, I haven't [yet] done anything larger than 30-ish zones, and 3 keypads; soon to do one with 4. I've also not yet used a keypad input or output, but rather have home run everything to the Elk or XIN. I've also placed SP12F's at each keypad, to which I've run 18/2 anyway. So, if there is an existing 22/4 in place, I've just used that as a sacrifical pull cord to pull a Cat5E and 18/2.
I also do a fair amount of RJ-45 terminations, which makes using the DBH simple [for me]. If I have to troubleshoot a device, I've literally unplugged the working devices, moved the RJ-45 terminating resistor, and troubleshot the individual device on the DBH - just very easy to do without having to do anything with crimped connections.
Actually, the terminating resistor really isn't necessary to get the system running, nor would T-taps...but that's strictly a non-supported application and not something I'd want to attempt to troubleshoot on a 485 bus. Once you understand the voltages on the bus it's easy enough to figure out where it breaks.
For a retrofit with access, sure, you can use the cable as a pull, but otherwise for a prewired situation or one with finished basement/attic, that day is going to be no bueno.
Like I said, the largest problem I have is not being able to split out the power or grab the COM and Z pins....almost impossible while making any form of professional RJ 45. I dove into the M1 world headfirst from the old Honeywell/Ademco Vista panels, so a lot was learned on those first installs and later integrations...also a lot of retrofit on very large systems where recabling is not possible or practical. I think the smallest M1 I've put in had 48 zones and almost every one has had a separate power supply.
For a retrofit with access, sure, you can use the cable as a pull, but otherwise for a prewired situation or one with finished basement/attic, that day is going to be no bueno.
Like I said, the largest problem I have is not being able to split out the power or grab the COM and Z pins....almost impossible while making any form of professional RJ 45. I dove into the M1 world headfirst from the old Honeywell/Ademco Vista panels, so a lot was learned on those first installs and later integrations...also a lot of retrofit on very large systems where recabling is not possible or practical. I think the smallest M1 I've put in had 48 zones and almost every one has had a separate power supply.
