PLC 5/11 Comm errors.

Hey guys. I'm having a problem logging on to a PLC-5/11. At first, when trying to log on I noticed a flashing red light at channel 1A status indicator. It has turn back to green now, but I still can not log on to the PLC. It is up and switched to Run mode as usual. Here is a picture to see what's going on. In the picture, the Communication Screen is flashing between 2 errors for the device...

Well it's hard to read, but chech your device type in the DF1 driver config. page. It look like it's set for a SLC.

The Autoconfig isn't completing, which is why you still have "SLC/MicroLogix" as the Device Type.

DF1 Autoconfigure frequently has problems with USB/RS232 converters (you're using COM3, which makes me guess you have one). You can hard-set the DF1 data rate and device type and try to browse using the settings you think you have in the PLC-5/11.

The PLC-5 default is BCC error checking, and the default baud rate changed over the years; it was 1200 a very long time ago and changed to 19200. The actual correct baud rate depends, of course, on the configuration in your PLC.

A flashing red LED on the DH+ port suggests some physical errors or even a duplicate node address. I would solve the DF1 port connection first, then do some diagnostics on the DH+.

Channel 1A on a PLC-5/11 is usually configured for Data Highway Plus communications (DH+).
If your PC is connected connected serially,as per jkerekes'sd answer, use a DF-1 RSLinx driver targeting a PLC-CH0 device(not SLC/Micro/PanelView)and use the Auto Configure feature when defining the driver.
If this doesn't do it, there is probably an issue with the PLC's Channel 0 communications port.
In this case, another option will be to try to go Online with the controller using a DH+ RSLinx driver such as 1784-PKTX(D)/PCMK, however, this will require a suplementary PC to DH+ interface(PKTX, PCMK or a 1784-U2DHP USB-to-Data Highway Plus Cable with an 1784-U2DHP driver) wired up within the PLC 5's channel 1A network.

I suppose we should take a step back.

The PLC-5/11 was a New Platform PLC-5 controller, so it has a 25-pin Channel 0 RS-232 port. That's what you should be connected to with a serial port (built-in 9-pin or USB/RS232).

Channel 1A has both a 3-pin "Combicon" connector and a Mini-DIN8 round connector. These are physically connected together and are a DH+ port.

I don't know if Channel 1A can be reconfigured for RIO on the PLC-5/11.... I would have to go dust off a User Manual.

ken roach said:

i don't know if channel 1a can be reconfigured for rio on the plc-5/11.... I would have to go dust off a user manual.

Click to expand...

fyi, dust cleared off.