o.k, i'm may be wrong in some place but is it suppose to be an 300 baud,1200,2400 baud comm

there's a simple way to verify if you receive an OK from.
serin2 RXD,3313,[WAIT("OK",SRIN[0]]

SRIN[0] will have the next value send after OK.

you may also try
serin2 RXD,3313,[WAIT("O",SRIN[0]]

this will wait for O, you should have K in SRIN var.

let me know what is bout now

regards