I believe in a string, you enter '\x9A\x01\xA9' for example. Not sure if you use

9A 01 A9, \x9A \x01 \xA9, or 0x9A 0x01 0xA9 for the PEP2 database.

For how to build the command string...

For a good read and experience, I suggest again Barry's site.

[Link: the-gordons.net]

See Serial (232) Communication 101. Will help to explain process and items.

Then a few more links outlining problems with 232 communication on RFX and likelihood that your responses could become garbled due to implementation of 232 receive buffer on RFX9600.

These were located with a search for 'receive buffer clear'

[Link: remotecentral.com]

[Link: remotecentral.com]

And this last thread also has an example of handling a 'sliding buffer' where characters are added at the end and pulled off at the front. All intended to attempt to overcome the limitations of 232 on RFX9600.

[Link: remotecentral.com]