Question on 90-30 communication

Hi I have a ge 90-30 plc that I'm trying to communicate with , but I can't establish any communication with it. I think the cpu is a 311 and it works because the run light goes on and it reads the eeprom. I don't know which are the comm. parameters or a way to find out.



I will deeply appreciate any remarks on this matter

What are you using for communications? Programming software? Hyperterminal?

The communications port is on the power supply. It is RS-485. You will need a RS485/RS232 converter to talk with your laptop. In case you don't have a serial port on your computer, there is a list of USB/Serial converters that have been proven to work available on the GE Fanuc website.

Thank you Steve for your reply

I do have the adapter and I use the laptop on other 90-30 and it works fine, this one is in another company and I have never hooked up to this one.
I was wondering if I take the batery off to get the plc to the the default status and use the default parameters to communicate it might work.
What do you thing?, let me know.
Thanks

If you remove the battery with the power off, it will revert to the default communication parameters. That will also erase the program, so be sure you have a backup before you try it.

If you can find a hand held programmer (and cable) for a 90-30, that will autoconnect at whatever port settings are current. If you don't have a 90-30 handheld, but you do have Fanuc CNCs in your plant, the Fanuc DPL/MDI handheld is the same unit but with a different keyboard mask.

You might also check to see if there is 5 VDC between pins 5 and 7 on the 15-pin Com port on the PLC power supply.

Thanks Steve
I had a e-eprom with the program that I wanted to install, so I took the battery out and it worked.
Thanks a lot for your help I'm super glad you responded