How restart wdt using Timer2

[aasanchez]

I have a small circuit which is something basic, I get a information via xbee and I relay via rs485, both devices are connected to the same UART port, a 18F4520, I noticed that when connecting two transmitters the pic works so wrong, restarts, and crashes, does not work, once I happened something similar and solved using the wdt, and since that time had a ds1307, performed the restart_wdt () i2c communications, however this time I have the same problem but I have not nothing to communicate via i2c, I thinking of making the restart_wdt (), using one of the timers, but this I was unable to apply it correctly, someone can help me or show me some code where using a timer to run the restart_wdt (). .. thanks for your attention ..

[asmboy]

start by showing your code with an explanation of what is failing.

a link to the schematic is not a bad idea either.

[PCM programmer]