Then I suggest you find out. If your CF reader needs RS232 and you aren't supplying RS232 signal levels, it's not going to work.
My next step will be to see if I can generate a schematic by tracing pins. More to follow on that front...
This is what the manual says in terms of commands:
Start character: @
End character: 0Dh
The receiving side ignores data received prior to "@". If code data is received without receiving "@", the data receive error code will be returned. The tolerance for send/receive clock error is ±10%. For sending a command, wait more than 20ms after reception of a response (OK, ERR or Status). Reception of 0Dh or timeout is used to determine the end of a command. Timeout occurs 1 second after the reception of the last byte.
The manual also lists a table of commands and request commands. This is the one I was trying to use as my test:
Card Condition .............. “@0?CD” + CR
Would the line
fulfill the start and end characters?