#Dsc Serial Protocol how to#
#Dsc Serial Protocol series#

Connect it so that the red wire is directly beside the 'SO' printed on the circuit board. The data line seems to transistion on either the falling or rising edge of the clock (or in the middle), which led Kortuk of to belive that it is NRZ encoding which I'm not sure of yet but here are some OLS dumps of the data and clock lines hopefully with teamwork we can figure this out.The Pin red and yellow may be inverted, the pin number 1 is the red and in the table Device 2 is set as 4, the Mini-Molex has the pin 1 in the red wire location?Д¬onnect the Molex to the PC-Link connector on the alarm panels main board. From what I know about this protcol so far the clock line runs at 1kHz with 50% duty and oddly enough only does so for 41.6ms then it stays high for 5.4ms and starts all over again. There was another thread about it on this forums but it ended prematurely with the guy just checking one bit for stay or away mode. I am trying to understand this protocol that my DSC 1555 alarm uses between the base and the keypad, but issue is its propriatary of some sorts. I'm not sure why Zone 1 and zone 2 are the same and Zone 3 and Zone 4 - I was getting a definate bit set for each LED - good luck if You are still working on it. The statement about rising edge clock vs the falling edge clock is correct - then each bit of data represented a keypad button or an LED on the keypad depending on data direction.

#Dsc Serial Protocol series#

What model of alarm panel is it? I did a similar thing years ago with a DSC PC1550 (Classic series panel) - nor sure how much has changed with the newer panels. Thanks for that, I don't believe the data to be encrypted as another person on avrfreaks managed to find the bit that is set when the alarm is armed and unset when it isn't (hrm i can't put in newlines in this comment) panneerselvam. With NRZ you are just checking if there was a change or not. The fact that it changes on both clock edges is just a sign that both clock edges represent a point that a 'bit' of data occurs. I cannot open the files right now, but I hope this helps. That is my best informed guess based on your explanation. On the note of the synchronous protocol, chances are that the protocol is a. Chances are that the keypad has a very simple protocol and the controller has some strict constraints on how many button pushes it will accept and such. With some work and more questions you might successfully figure out the kind of encryption, and then, if it is poorly implemented, decode it. There is no simple answer to decoding a protocol, if they have a good encryption scheme setup then you are probably going to be up &$%* creek. The Data line appears to change on on either rising or falling edge of the clock (0 is the Data line, 1 is the Clock line). The Clock line is confusing tho, its a 1kHz clock at 50% duty but only runs for 41.600ms then it goes high for 5.400ms and then starts over again.

#Dsc Serial Protocol how to#

So has anyone messed with this before or can give me a few beginners tips on how to reverse engineer this protocol? The wiring is simple: Vcc, GND, Data, Clock The Vcc is +12 volts and the data/clk lines are between +8-10 but work just fine through a voltage divider to the logic analyzer. I'm plan to interface a atmel avr with my alarm system in home but the issue is DSC has a propriatary protocol between the keypad and the base. IT-100,DSC Serial Integration Module RS232 Serial Interface - Buy online at Aartech Canada. 00 is an integration module used for connecting DSC alarm systems to HVAC, automation and other systems by way of its bi- directional serial interface.