Hi,

Here is some of the X3 pinout:

1-GND, 2-GND, 3-??, 4-??, 5-ID0(? open), 6-ID1(? grounded for a GPS cable), 7-+DC, 8-+DC,9-+DC, 10-+DC, 11-TXD(out), 12-GND, 13-RXD(in), 14-RTS, 15-GND, 16-CTS, 17-DTR, 18-3v3(in/out ??), 19-DSR, 20-USB_PWR, 21-USB_D-, 22-USB_D+, 23-EN(?), 24-??, 25-??, 26-GND.

Levels are 3.3V, for real RS232 a voltage converter like MAX3232 is needed.

Vic.