DSC pc2550 keybus interface?

[Mike Scott]

I wish to track zone activity in real-time on my computer (among other
flaws, I'm a programmer). What I don't know is how to sniff data from the
system. I've read about the printer output functionality, but this doesn't
appear to provide real-time zone activity -pass. I can't find anything that
confirms how the keypads communicate with the panel. Is this RS-232 (like
the printer interface)? If so, I could tap the TxD and GND, and watch the
bytes coming down the wire. Has anybody done this successfully? -with
thanks

btw: my apologies if this is an often asked and answered question. I've
spent a few hours googling and found nothing current, or terribly helpful.

 

[Jackcsg]

DSC uses TTL communication. I would imagine using a TLL to RS232 converter
to capture information would work. I have never tried it (or had a need to)
but I have extended TTL communications over fiber optic cabling. Black Box
probably has a converter you can mess around with.

Jack

 

[Mike Scott]

My system is fully installed (has been for some time). -thanks anyways

 

[Mike Scott]

Hi Jack,

Hmmm... I received a direct reply from someone that diagnosed the DSC
keybus a few years ago with a logic tester. He discovered that the bus is
synchronous, not async ttl. The connections from the keypad are: 12V, Gnd,
Data, Clock. While I have seen a few TTL references to the keybus, they
typically have "I believe" or "as far as I know" type statements. This
could be a case of "Saw it somewhere else, so I'll pass it along". p.s. No
offence intended to past posters. The one thing I'm learning from this
thread is that interfacing my PC2550 to a PC will not be a trivial task.
One clever idea I read elsewhere is to use an actual DSC keypad as the
interface. Just intercept the LEDs and pushbuttons, and manage THESE from
the computer (via whatever). Interesting...

Are there any DSC-authorized technical specs on the keybus, or is this one
of those "industry secrets"?

 

[Jackcsg]

I don't know of any "official" DSC doc's that outline the communications
format. A majority of the Manufacturers use TTL for their format. I'm sure
that most differ in the code, encode method. I use DMP, and had an
installation were I needed to extend the keypad bus 1 mile to a Gate
Controller for an access point. DMP tech support informed me of their TTL
protocol, and I was able to, although not supported by the Manufacturer,
extend the bus using a TTL converter from Fiber Options. DMP also
manufactures a Network Router which can accentually adapt to any
manufacturers control panel, including DSC. It has six zone inputs, and six
outputs. Configured in a "slave" mode, these signals can be routed across a
data network. They (DMP) also has a software package which can receive these
alarm/signals, and acknowledge them. When you tie this Router into a DMP
Panel, in keypad mode, the router routes all signals from the keypad bus,
over a data network. DSC also has a Network Router, which can do the same.
I'm not familiar if they also have a software package for Monitoring these
signals in the same fashion as DMP. I use these routers to send signals
across the internet from the DMP panels. In their software package is a
hyperlink, which I program to go to a Network Camera and verify alarms with
video. I have a demo system which is online, and I get access through PC
anywhere to demo this to my potential customers. They can see how it works
in real time, and respond as if it were their own system, along with access
to the virtual keypad that controls the system. It is affordable, but not
free. You may end up spending allot of time experimenting with something
that already exists, just not in the DSC platform. If time doesn't mean
money to you, than your efforts may prove to be beneficial. Good luck. Keep
us informed on how you make out. I at least would be curious as to your
results.

Jack

 

[Jackcsg]

OK if you say so. Apparently you, with your infinite wisdom, don't know
either. At least has taken me 33 years to know that. Mike my left testicle
knows more about this industry than you. How's your GED coming along?

Jackcsg

 

[Jackcsg]

Right next to your knowledge of DSC. There are only three shareholders in my
company, and there all family. Then again with you limited education, you
wouldn't understand Corporate Business Structures. Again where that GED
might help you in life.