No Comms w/ 1785-L11B

rwensley · May 14, 2008

I am trying to communicate with this PLC from laptop/RSLogix Com1 to CH0 on the processor and can not establish comms. I have verified dip switch settings and cable connections.
Any help is welcomed.
Ron

Mickey · May 14, 2008

See procedure below. Do you have a real serial port or a USB to serial adapter. Not all USB to serial adapters work.

rwensley · May 14, 2008

Thanks

Thanks for the pdf Mickey. It turns out that this new cable had only the RX and TX connected. There I go assuming again.

Ron

rwensley · May 14, 2008

Still No Comms

I cut apart the cable and made the connections as per the pdf. and reverified. Still no comms using the Auto-Configure button.
Any other help?
Thanks,
Ron

OkiePC · May 14, 2008

Have you checked the switch settings for the serial port?

Also, there is the possibility that the port is set for user mode. If so, then it is possible to send ASCII control characters to switch its mode back to system (DF1) which is what you want to use with RSLinx.

Do you have an offline copy of the program?

Do you have the means to connect to the PLC5 via the DH+ channel?

That's all I can think of right now.

Mickey · May 14, 2008

Tell us a little more about this PLC. Is it a working PLC? ( controlling something or are you just trying to learn). Was there, is there something connected to the serial port? If its not controlling anything then you can reset it to its default condition by removing the battery. Don't do this if its controlling something.
Double check your cable ( you need a null modem cable)

rwensley · May 15, 2008

The PLC 5/11

Was removed from an old turbine control system that has been upgraded. I have now idea what the program is on the plc. I do know that it used the serial (CH0) port to interface with a westinghouse P-2000 control computer.

I am trying to set this up as a trainer so removing the battery and losing the program is not a problem. I will also purchase a new null cable and see if that resolves the issue. I'll let you know.

Thanks for the ideas,

Ron

Gil47 · May 15, 2008

The PLC 5/11 also uses DH+ , do you have it available to you.
If you can get online with DH+ you may be able to see if the RS232 port is configured for a different comms set up

rwensley · May 15, 2008

Removed the Battery

And I am now able to communicate with the plc.

Thanks for the help with this.

Ron

Mickey · May 15, 2008

Your Welcome

No Comms w/ 1785-L11B

rwensley

Member

Mickey

Lifetime Supporting Member

rwensley

Member

rwensley

Member

OkiePC

Lifetime Supporting Member

Mickey

Lifetime Supporting Member

rwensley

Member

Gil47

Member

rwensley

Member

Mickey

Lifetime Supporting Member

Similar Topics