I am programming a MSC-400 and am very familiar with configuring it for IR but not so familiar with it for RS232. Here is my problem. I am trying to control a STR-DA4300ES receiver. I have all the hex commands I want to use mapped out in excel and if I use software such as Realterm to output them to the STR-DA4300ES the command is recognized and works like a charm. When I attempt to put the code in as hex in the MSC and press the test button I get different values other that what I have entered. For example:

Sony Tuner Preset A1 = 0x02, 0x04, 0xa1, 0x42, 0x01, 0x01, 0x17
When entered into the MSC-400 as 02, 04, a1, 42, 01, 01, 17
the MSC-400 outputs 18, 60, 06, 1E, 80, 66, 06, 7E, E0.

I know this because I have intercepted the output back into my computer. Am I missing something basic? Your help is greatly appreciated.

After 2 days banging my head against the wall I figured out the issue. For anyone else that is having the issue you need to make your port changes such as baud rate and upload this to the unit before the unit will recognize the new settings. I had made the changes in the MSC editor and been trying my codes but had not uploaded the baud rate port changes. Basically it was an order of operations issue. Hope this helps someone else.