[mythtv-users] DCT2524 cable box suddenly stopped responding to RS-232

[Marc Randolph]

Howdy all,

My MythTV setup has been humming along pretty well for some time now,
effortlessly controlling the DCT2524 cable box via RS-232 when all of
a sudden, sometime within the past week, recordings started to fail.
LiveTV doesn't work either.  Looking in the backend log, I find:

  Communication failed after 5 tries
  0
  2008-10-10 00:00:15.306 ret_pid(14125) child(14125) status(0x100)
  2008-10-10 00:00:15.310 ChannelBase: external tuning program exited
with error 1
  2008-10-10 00:00:15.311 TVRec(1) Error: Failed to set channel to 186.

I've rebooted everything: backend, the cable box, and just to be safe,
the video capture box (pvrusb2).  Unfortunately, running the channel
change program manually confirms the problem:
  $ channel -v 202
  Attempting to initialize DCT
  No response to packet
  No response to init_1; trying to continue
  No response to packet
  No response to initialize_2
  Initialization failed
  [repeated four more times]
  Communication failed after 5 tries
  0

After this, it suddenly dawns on me that maybe Time Warner has
remotely disabled the RS-232 port on the cable boxes here in Dallas.
I'd call them and ask, but I'm sure I'd get the same response as last
time when I called just asking if they could turn it on: Someone that
sounded very helpful and knowledgable had never heard of the RS-232
port, much less it being disabled and someone having it re-enabled.
Turns out I didn't need to call - it was already enabled.  So...

1. Anyone else in the Dallas area controlling a Time Warner cable box
via RS-232?  If so, is it working or are you having trouble?
2. Anyone know of a way to verify if the RS-232 port is enabled or not
on a Motorola cable box?

Stupid me didn't record what S/W and firmware were on the cable box
when it was working.  Right now, it has:
S/W ver 74.24-4004  and Firmware: 03.18

I don't know where my old RS-232 break-out box is, so I'll probably
look at the signals with a scope this weekend barring any other ideas.
 I was hoping to avoid having to use the IR-blaster, but will switch
to it if no alternatives can be found.

Thank you!

   Marc