GE Unable to Toggle Online Mode During Download

Hi all,

I am trying to download a program to a CPU374 GE PLC serially and am getting the following error:

"Unable to toggle online mode"

During the download. Can anyone tell me what might cause this error?

Any help is appreciated.

Thanks!

If you are in monitor mode and can't get to online mode, it could be because someone else is already online. Only one person at a time can be online.

Steve, thanks for the quick reply.

You have exposed my inadequate question. I need to provide more info.... I am using a 10 slot rack with only one PLC (A CPU374)in the fist slot. I am connecting directly via the serial port on the power supply and no other external connection is being made. I am able to get online and set the mode to Programmer Mode, but when I download the program the process stops at the Downloading Rack Configuration, then it says that it is attempting to reconnect and THAT is when I get the error. This happens regardless of what I am downloading (i.e. Hardware and/or Logic).

As far as I can tell I can only download to the PLC while I am connected in Programmer mode. Since I am the only one connected, I am unsure as to why it would fail to change the online mode back to Programmer mode during the download which appears to be what it is failing to do.

Are you using a USB/serial converter or do you have a PC with a real COM port? All USB/serial converters are not created equal and some have problems maintaining a connection. What software version are you using and what OS is it running under?

I would try downloading just the hardware configuration serially, even going so far as to remove the I/O modules from both the rack and the configuration file and downloading a hardware configuration that only has a CPU module with an IP address assigned. If you can get to the point where you achieve configuration equality, switch to Ethernet communications to download the program and the actual hardware configuration file you need to use.

Have you tried to do an upload and go online with the PLC? Can you force the PLC to go in Run mode from the key?
There are different types of racks - make sure you have IC693CHS391 (hardware, not in the program).
My guess you have some kind of configuration error/bad HW.
CoS

I'm betting that you have PME 8.00, I have seen similar issues with serial comms and that version. As Steve suggested, switch to Ethernet and you should be good. If you don't know the IP address that CPU works well with the "Set Temporary IP" utility. Turn off power and remove the CPU to find the MAC ID.

Russ, I think the MAC address is also on a sticker on the front of the CPU.

Everyone, thanks so much for all the suggestions. Based on what I am hearing it sounds like the issue is probably the serial connection. I was able to determine the IP address and once I was connected via ethernet there were no issues downloading to the processor.

With that said, can anyone suggest a USB serial device or Ethernet to Serial converter that works with GE PLCs and is supported by Windows 7?

I use a USB/RS232 converter from Staples. The model number isn't printed on the unit, but I doubt if they offer multiple models other than USB/RS232 and possibly USB/RS485. I got it because the Radio Shack converter I formerly used doesn't work under Windows 7.

Thanks, Steve. I'll grab a Staples serial device and see if this provides better results for next time. For anyone else reading through this thread, I think, whenever possible, the ethernet route is probably the better way to go. I had forgotten about the "Set Temporary IP" utility RussB mentioned, this is also an excellent option.

Thanks to all.