Autoconfig message timeout error

Ok guys, I've searched and searched, and have come real close to getting my questions answered, but figured I should give my details so it is specific to my situation. All the other situations that are very close to mine do not always have the same details as mine.

So I am trying to communicate with a couple of AB PLC's. A ML1000 and a SLC5/03. This is an old system, but not sure of the exact time it was put in place. The original integrator is no where to be found, and most data on the system is incorrect. So it really is a blind system.

They had/have a radio system set up for communications. It has not worked in who knows how long, and no idea of when it quit working much less if it even did work. The PLC's were cabled up to the radios with null modem converters, the little male/female adapters you can buy at radio shack. I can take pictures if necessary.

My computer is a tablet running widows 7. I am using a usb to serial converter. I know the converter works, because I have two different ML1000 and a SLC5/03 of my own that I can talk to just fine.

I have tried numerous things, and have even talked to an AB tech on the phone. He gave me one suggestion, to set up default configuration and see if the auto brows will pick it up, but it did not work, or I did not try it all.

Other than that he said for sure it was a protocol error message I was getting and it is more than likely set up for DH485. He said I would have to use the 1747-UIC cable.

So is there anything else I could be missing here? I hate to buy the cable just to find that it does not solve the problem. Could it be a full/half duplex problem? I thought I tried most all different settings then letting it auto brows, but maybe I forgot that one?

The PLC's are running fine, but there is no clue as to a backup of the program so a hard reset(if it were possible) is out of the question.

Fill me in please, thoughts and idea's.

Thanks

Welcome to the Forum !

If you get a 1747-UIC, you will very likely be able to connect to the SLC-5/03 controller via the Channel 1 DH485 network port.

That will allow you to upload the program (as long as it hasn't been locked down) and get a look at the Channel 0 serial port setting in the SLC-5/03. This may give you enough clues about the port configuration that you'll be able to connect to the MicroLogix 1000 as well.

Since there was a radio involved, it's unlikely that either controller has a serial port with a default configuration. They might be set for half-duplex, or for some sort of handshaking function that you aren't familiar with.

If you can closely examine the serial cables between the modems and the controllers, that might give you a hint about what handshaking (RTS/CTS, DSR/DTR, both or none) is being done.

Exactly what model of USB/RS232 converter do you have ? The Forum really likes the Keyspan/Tripplite USA-19HS.

Many USB/RS232 converters don't support the traditional 'Autoconfigure' function, because they can't switch serial framing settings fast enough.

If I were faced with a system like this, and didn't have my traditional tools, I would connect to the SLC-5/03 serial port using the RealTerm utility and watch for data packets being transmitted, then adjust my Data Rate until I saw data that looked like DF1 protocol (it should start with 0x02 and 0x03 byte values, and end with a 16-bit CRC).

Ken Roach said:

Welcome to the Forum !

If you get a 1747-UIC, you will very likely be able to connect to the SLC-5/03 controller via the Channel 1 DH485 network port.

That will allow you to upload the program (as long as it hasn't been locked down) and get a look at the Channel 0 serial port setting in the SLC-5/03. This may give you enough clues about the port configuration that you'll be able to connect to the MicroLogix 1000 as well.

Since there was a radio involved, it's unlikely that either controller has a serial port with a default configuration. They might be set for half-duplex, or for some sort of handshaking function that you aren't familiar with.

If you can closely examine the serial cables between the modems and the controllers, that might give you a hint about what handshaking (RTS/CTS, DSR/DTR, both or none) is being done.

Exactly what model of USB/RS232 converter do you have ? The Forum really likes the Keyspan/Tripplite USA-19HS.

Many USB/RS232 converters don't support the traditional 'Autoconfigure' function, because they can't switch serial framing settings fast enough.

If I were faced with a system like this, and didn't have my traditional tools, I would connect to the SLC-5/03 serial port using the RealTerm utility and watch for data packets being transmitted, then adjust my Data Rate until I saw data that looked like DF1 protocol (it should start with 0x02 and 0x03 byte values, and end with a 16-bit CRC).

Click to expand...

Thanks. I have seen your posts in the past about issues similar to this. I am hoping the cable will do the trick. I am not up to speed with serial communication protocols. I know, I have been fed with a silver spoon just using Ethernet TCP/IP.

So you are thinking that both devices might not be be configured for 485? I guess it would be a means to an end, but I was hoping that the cable would be the end itself.

I am very new to Allen Bradley stuff. I have only dealt with other brands of controllers. That's not to say there was not a learning curve with them.

I kind of am hesitant that the ports would be configured for 485 from the get go. It seems to me, in my limited knowledge, that 232 is what you would use if you were doing modbus over a local radio network. I could see, from what I have learned, that a 485 would be best if they were all local but separated by some distance from each other.

Manhattan is the brand of converter I am using. Like I said though, unless its a complete fluke, I can use it just fine with other controllers. Or, throwing this out there for consideration, if the other controllers are set for default coms, then the autoconfig does not really matter?

I am at a loss. But I guess your right in that the cable will at least let me see the one's settings and then I can use them on the other. I will look up that RealTerm program your speaking of. Like I said before, I am still a pup at all of this, but I catch on eventually when I get in the middle of it. Sink or swim, I prefer to swim.

If you had to give a crash course on RealTerm, how would you do it? I am interested in giving it a try at least.