PLC 5 Communication Problem

[DoubleL 2]

HI, I am encountering a problem that AB doesn't seem to have an interest in. I have a machine with a PLC 5 that I communicate with through the serial port to my laptop. I know that a DH+ card would be better but I only have a few machines that have PLC 5s that I have to service. OK my problem. When online with the processor via the serial port with the baud rate set at 19.2k I get kicked offline about every 10 minutes or so even while programming. If I catch it soon enough I can refresh the connection by going to RSLinx and AutoConfigure the driver again. To get around this problem I had to lower the baud rate to 9600. It still kicks me offline occasionally but the main problem with this is that it makes trouble shooting harder due to slow update times. For background the program size was increased this past year because of equipment additions. I have tried increase the reply timeout value but that didn't help. The last averall scantime recorded was 55ms and the max was 91ms. Has anyone encountered a similar problem? Thanks, DoubleL

[mgvol 0]

Have you tried looking at DF1 driver diagnostics in RSLinx? If you are getting a lot of timeouts and re-tries, you may have a fualty cable.

[DoubleL 2]

Well it's a fairly new cable and I use it with panelviews, 1394 servos and other plcs and I haven't had trouble but could be. I do use a null modem adapter on the PLC 5 so that may be the problem.

[mgvol 0]

Yeah, I would start looking there, because it sounds like a physical problem. I once (many moons ago) had a problem with an old Westinghouse 2000 PLC where it would fault the processor every time you disconnected the programming cable; first thought it was the cable but turned out to be the com port on the CPU itself.

[guillencito 0]

Have you tried to go online witha PC, or with the laptop connected to AC power? Because I found a similar problem with my laptop. When I am connected with a laptop powered only with the battery,after a few minutes, the connection is broken. Then I connect the laptop to AC supply, and the connection works fine. I suppose that, because the battery power is decreasing, it don't support the serial connection. Try it. It could works. Regards

[DoubleL 2]

Yes most of the time I am connected to AC power when connected to this PLC. I think I may just have to break down and get my boss to buy me a PCMK card so I can communicate via DH+.

[DoubleL 2]

I recently got a chance to visit another customer that has a PLC5 on their machine and I have the same problem here so that rules out the Processor. I also tried a new cable with no sucess. Any other Ideas? Could it be a setting on my computer. This has happened now with the newest and the previous versions of RSLinx and RSLogix 5. I am running Windows XP SP2.

[mjisaacs 0]

I have experienced the same problem, but it was on a Windows 98 machine. I had somehow gotten some corrupted system files (Windows not Rockwell) and, to save time, did what is referred to as an installation overlay. I installed a newer version of 98 than I originally had on the laptop. After this, I continually got kicked off line with PLC 5's (using a serial cable) and it remained so until that laptop went to processor heaven. Have you installed a new OS or done an overlay?

[DoubleL 2]

No new operating system just the updates. I guess it could be a Windows update that caused it. I wouldn't know which one since it started doing this ayear ago.

[Ghettofreeryder 0]

Firsy, id try removing all the drivers from rslinx, and go to your services.msc and shutdown the rslinx service. Change it to automatic, this way, it only starts when your in rslinx and the com port is open. This had fixed my problem many times. I think this problem occurs because the df1 drivers is ghosting. If that doesnt work, we have some pcmk cards for sale on outr website for relatively cheap, email me if you need some more info