Communication problems

[tom.ganc 0]

Hi there I have really strange communication problem, but first few infos about system configuration. 1. Mitsubishi FX1N PLC with RS232 card installed 2. Westermo TD33 modem connected to PSTN phone line and linked with PLC via RS cable I'm not able to communicate with PLC using phone line. When I'm trying to dial PLC from my laptop I can hear that laptop is dialing, modem is answering and GX Developer is saing that line is connected. Then when I'm trying to go to monitor mode GX Dev is saing that cannot communicate to PLC. I'm sure that program in PLC is exactly the same that in my laptop. I have checked cable between modem and PLC, I have replaced PLC, replaced modem - still nothing. There is one more think I connected my PLC with laptop via SC09 programming cable to check program. I went online without any problems. After that I plugged in phone line to my laptop (I didn't touch SC09 cable) and I dialled PLC everythink was PERFECT. I was able to go on monitor mode (using phone line), but..... as soon as I disconnected SC09 cable all communication died. Please help because I have no idea whai I'm doing wrong. Thanks Tom

[funfrok 0]

Did you change the com port to the port which modem is connected? Maybe communication was still through the SC09 cable when modem was connected.

[FNMdeJong 7]

How did you configure your modem, do you use the right string. With Hayes commands (AT) you can set a configuration inside the modem, i.e. use flow control, auto answer an stuff like that. If you do not set the right configuration you can get a connection but no communication.