Serial Control of RSP-976

[sanfransoxfan04]

First question, does this unit provide the verbose feedback that other Rotel units do? I'd love feedback on volume status, input selection etc.

I am trying to control it with Crestron and having problems. I am not sure if the problem is my hacked together cable or the serial strings I am sending.

It has an RJ45 connection that I am connecting to the Crestron Procesor. I followed the pin assignment carefully as outlined here to make my my own RJ45-DB9 cable:

http://bwgroupsupport.com/downloads/rs232/rotel/RJ45connection.pdf

I then tried following the Protocol document found here:
http://www.rotel.com/NA/Support/Down...s/rs232%20pro\
tocol%20files/rsp976%20protocol.pdf

The document suggest 2400 baud but I also tried 19200.

Using Crestron I would send serial strings but I could not get the Rotel to budge.
I would try:
\xfe\x03\xc0\x10\x4a\x1d

I tried many other combination as well. Sometimes I would get a
response, many times I would not. Not sure if the response was garbage or not, but the 976 never changed a thing.

Any advice?

[Kevin D]

Have you tried connecting the cable to your PC's serial port and see what comes over a terminal? If you see the text display come across when you adjust volume, then at least half of your cable right. The second line from the response should be a readible version of what's on the front. The feedback is automatic with any change, so turning the volume knob should produce something.

If you don't get a response in a terminal, your cable's wrong.

Kevin D.

[sanfransoxfan04]

Thanks for the reply, I wasnt sure if the 976 supported that level of feedback. Now I'm more anxious then ever to get it working. Hyper Terminal isnt showing anything on the processor change. I will fiddle with the cable some more. Am I to assume that the only pins I need connected are the ones outlined in that wiring document and all the others are not required?

[sanfransoxfan04]

I feel stupid. I have little experience in making serial cables or reading pin out configurations. When I saw

RJ 45 DB 9
#3 TX #2 RX
#4 Gnd #5 Gnd
#5 RX #3 TX
#6 Gnd #5 Gnd

I though RX should go to RX and TX to TX.. WRONG.
I feel like an idiot. I am now able to send and receive data from my Crestron system.
Oh yeah, learning to calculate checksums was also handy.

[Kevin D]

I'm an AMX guy, so I don't know too much about Crestron... But, I'm sure figuring out how to handle the bit-wise feedback for the surround modes will be fun.. From the looks of it, not much is sent in the first string since the 976 doesn't have a tuner.. I probably wouldn't worry about bit-wise.

The newer models are real fun too. Different commands for zone's 1-4 & rec zone, a lot of feedback through bitwise (in the same string as the ascii text too), plus way more commands then the remote has.

Glad you got it working!

Kevin D.