DAHUA RS485 protocol

[riogrande75]

Hi!
Im currently analyzing Dahua's RS485 protocol that is used to interconnect VTO/VTH's and expansions.
My goal is, to add a fingerprint from Dahua's security products (ASR1102A) and maybe other stuff.

Is there any dahua RS485 protocol (DH-SD?) description available?

 

[LIOR]

hi!
Did you find any solution for dahua rs485 protocol?
i try to find anything about "start of text" and "end of text" for access control

do you know something about it?
thank you

 

[riogrande75]

No, unfortunately I did not find any useful information.
So I ended up in buying a VTO2000A-F. I tried to analyze the RS485 protocol with it, but believe me, it is not just a simple serial connection.
Tons of messages are transmitted in both directions even in idle state, so I gave up in decoding them. I don't even know the used baudrate...

What do you wanna achieve? Maybe I can help you in another way.

 

[riogrande75]

In the new V4 firmware images, there are now options to setup RS485 baud rates and choose protocols. This opens at least the possibility to analyze RS485 bus.

 

[Philip09]

and this analyzer? RS232 & RS485 Analyzer| Log and Monitor COM Activity