GSM Module ASCII Communication using COM_SEND / COM_REC
Iam communicating PM573-ETH with TMAS T61-EHS GSM module for sending/ Receiving SMS at RS485 (ASCII Protocol),
now when i try to send "AT" commands using COM_SEND block sometimes it communicates and sometime it dosen't.
Can anyone provide an example program or how to use COM_SEND / COM_REC blocks for Communicationg GSM module.
I can't find much about it in Help file.