First, make sure you use an IOGear USB to Serial adapter (there are a FEW other brands that will work - Belden is not one). This has something to do with the chip inside the converter.
Second, make sure you are using a null modem adapter between the CM232 and the USB to Serial adapter - also make sure the CM232 is firmly plugged in to the RP6...stranger things have happened.
Third, double check that you are sending commands out of the right port on the RP6 - right click and edit properties - you should see a light blink on your adapter and the port on the RP6 when the command goes out. By the way, it is easiest to troubleshoot if you create a couple of buttons (ie. ON and OFF) by right clicking and using the RS232 tab rather than using the macros. After getting individual buttons working, then use in macros.
Fourth, make sure you have the latest in firmware for your HR20. I've never done this with an HR20, but use H20s ALL the time. DTV just recently sent down a firmware "upgrade" that took the baud rate for the comms from 115200 to 9600. It was originally an unpublished 115200... Your box MAY still need to be changed (in other words, it will only respond to 115200). Again, I have only integrated H20s, so the HR20 may be different. To force a new firmware update, unplug the DTV box, plug back in, watch tv for the blue "hello" screen. Use DTV remote and push "0,2,4,6,8 Enter" to force the download. It generally takes awhile to download, but there is a progress meter...
Fifth - Use this format exactly for strings (place box in HEX mode, use capital letters and don't forget spaces):
Power ON: FA 82 Power OFF: FA 81
Those could be backwards - I'm doing it from memory. Let me know if this helps!
