[mythtv-users] Digital Cable

Ray Olszewski ray at comarre.com
Sat Feb 28 13:56:09 EST 2004

At 11:02 PM 2/26/2004 -0500, John F. DeLuca wrote:
>I actually have 2 cable boxes.....a Motorol DCT2224 with a serial port 
>that is inactive
>and a HD Motorola 6xxx (can't remember off the top of my head) with a 
>whole bunch
>of outputs (firewire, etc) but no serial port at all.  I was rather 
>surprised that it had no
>serial port at all.
>I determined on my cable box which has the serial port that the port was 
>inactive as I
>plugged in my Tivo serial cable, configured Tivo (though the Tivo 
>setttings) to use the
>serial port vs. the IR blaster and told it the make of my box.  Tivo 
>tested the port and
>determined it was unable to change channels via the port. :(
>My cable co is Comcast (Atlanta) and the good folks there just don't know 
>what I am
>talking about when I asked about the serial port.  Useless.

Your negative results from the TiVo test are indicative but, I *think*, not 
definitive. You might want to take a moment to do what I think of as the 
drop-dead test for serial-port functionality on DCT2xxx devices. Run this 
short script and see if it turns the cable box off, then back on 2 seconds 

(You may need to change the serial-port designator to match your setup. And 
be sure to use a straight-through serial cable, not a modem-eliminator 
cable. Oh, and while the long "echo" lines may wrap in this message, each 
is really one long line in the script.)

# (slightly) adapted from script at

stty 9600 </dev/ttyS1
stty raw < /dev/ttyS1
echo -ne " \x10\x70\x00\x02\x03\x40\xc8\x27\x10\x03\x10\x78\x00\x0 
3\x03\x40\x00\x 68\x96\x10\x03\x10\x78\x00\x04\x10\x10\x40\x22\x0a\x98\ 
xbe\x10\x03" > /dev/ttyS1
sleep 2
echo -ne " \x10\x70\x00\x02\x03\x40\xc8\x27\x10\x03\x10\x78\x00\x0 
3\x03\x40\x00\x 68\x96\x10\x03\x10\x78\x00\x04\x10\x10\x40\x22\x0a\x98\ 
xbe\x10\x03" > /dev/ttyS1
# EOP----------------------------------------

If this does not work, it is safe to assume that the serial port is not 
enabled (or there is a hardware problem, such as a bad cable or a bad 
serial port on the Linux end).

If it does work, though, then either your prior failures involved some 
error of detail, or your provider has activated the serial port since you 
last checked.

BTW, I have Comcast here (SF Bay Area) and the serial ports do work, even 
though my Comcast is as clueless as yours. That's not to say Atlanta is the 
same as SF, though.

As to the other Motorola box (the HD 6xxx) ... I'm not familiar with it, 
but I did find a link to get its manual at


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