I'm trying to write a plugin for Eventghost for two Pioneer Elite Kuros. I have Eltima Serial Port monitor, using a GUC232 USB->RS232 cable.

I'm starting with a basic power on command. I've tried

\x02**PON\x03

I get no response from the TV.

[url=[Link: scores.warbirdsiii.com]]Pioneer RS232 Protocol[/url]

Is there anything special about the RS232 cable? Can I use a standard straight through 232 cable?

Will the KURO signal over RS232 status changes? (power state/channel/vol ect).
Will the KURO signal over RS232 a response to a failed/unrecognize command?

The string you have listed is correct and yes, it is just a straight through cable. I haven't used the eltima monitor before, how are you sending the hex 02 and hex 03? Most terminal emulators let you type 1 format of serial at a time ie: all ascii or all hex or all decimal. The string in all hex would look like this:
02 2A 2A 50 4F 4E 03

It will return status of some variables, I think input, volume, aspect and a few others, but not power. i have never looked to see if it returns failed commands.

Never tried it in all hex good suggestion. I found an older RS232 post talking about using hyperterminal. For whatever reason I couldn't get my other port monitor to see a response so I thought I was having some type of connection issue. As soon as I got a response over hyperterminal it didn't take long to write the plugin for eventghost.

I send the beginning and end characters as chr(02) and chr(03) in Python(eventghost).

I programmed one a couple of weeks ago. I tested it using this program below,
it is great . If you put the codes below into the macro section the TV works. You just need to use the correct terminators for the remote control that you are using.

[Link: sites.google.com]

$0211PON$03 for power on
$0200POF$03 for power off
I hope this helps
regards
Jem

Yo