Hello,
You can not use C2500 cable due to C2500 has 1x5 pins but you need 2x5 pins.
Here is an instruction how to get cable/pinout information:
1. be sure that you have downloaded and installed
latest Infinity-Box Pinouts update
2. run
Infinity-Box Shell
3. select required model
4. see detailed information about cable/pinout (Rx/Tx/Gnd pins and other information)
Here is an example of information given by Infinity-Box Shell:
Here is information how to build your own cable:
http:///vbb/showthread.php?t=342807