Unfortunately, Ciseco has no downloadable documentation, as yet. However, the link you supplied does say it is UART RS232 so you really need to know whether it is outputting RS232 voltage levels which will fry your PIC unless you use something like a MAX232 converter. It it outputs TTL, you still need to know the voltage levels. 5V may be too much for your 3V PIC. If 0-3V yuu need to see what voltage is needed for the PIC to see a logic high as the voltage may be marginal over your cable as TTL devices seldom output rail-to-rail voltages.