Hello,

We are having trouble trying to get the communication between our PLC (S5 6ES5 103 8MA03) and the operator panel (Coros OP15). We have tried to reset, changed the CPU, reload program from EPROM and nothing works. Any ideas? Thanks.

 

Check the following:

1) Is the OP program loaded?
2) Are there any error messages on the OP?
3) Are the communications parameters in the OP set to the same as the PLC?
4) Is the OP set to on-line or loop-through?
5) Is the cable plugged into the correct port on the OP?

 

Michael,

1. The OP program is loaded
2. There are no error messages on the OP.We can get output from PLC (alarms etc) but we cannot input to the PLC via OP
3. How do you check the parameters in the PLC and the OP?
4. I am not sure about this one.How do you find out which is which
5. Yes, it's the correct port.

P/S This unit was not in use for quite some time (6years) but it was working before that. We're positive nothing was changed in the system. Why it was put offline for all that time? I'm not sure why. hehe.

 

You said "We can get output from PLC (alarms etc) but we cannot input to the
PLC via OP". You left this out from the original message, and this is a very
critical point. If you actually are getting output from the PLC then the OP
and PLC are in communication. The display and keypad communicate to the PLC
through the same serial link. Make sure you really can trigger alarms and
manipulate fieds, and these aren't just internal OP error messages (e.g. "PC
not present" - which is a communications error).

A) If there are any fields where you can input data (a numeric entry or list
selection field), then try entering some data and see if it goes into the
PLC. This will tell you if the keypad is "working".

B) Look in the back-up copy of the OP program for the addresses where the
keypad is mapped to. If it goes to a DB, make sure that DB is present (and is
big enough).

C) I have seen a few cases where the keypad on the OP15 has stopped responding
due to something it didn't like in the OP program. This was with the first
generation OP15 using Comtext. This was due to some sort of Comtext bug, and
not due to the program we had entered. The only cure was to create a fresh
program and manually re-type the entire program back in (copying just seemed
to copy the problem over with it). The last time I saw this was a few years
ago, so I don't recall if *all* the keys were dead, or just the "F" or "K"
keys.

I response to your questions concerning my previous reply:

> 3. How do you check the parameters in the PLC and the OP?

This is done through one of the built in OP menus. Check your OP manual on how
to access these. It is possible for the original OP programmer to have set
the program to deliberately leave these menus out (or at least make them
inaccessible), in which case you are very limited in what you can do.

> 4. I am not sure about this one. How do you find out which is which
> (checking on-line or loop through)

Again, you check this using the settings in the built-in menus. The OP can be
in the following modes: "offline" (passive and not trying to communicate),
"transfer" (ready to recieve a new program), "on line" (operating normally
and polling the PLC), or "loop through" (similar to "on line", but allowing
another OP or a programming PC to share the same PLC port).

You need to access this menu to set the OP to "transfer" mode to download a
new program. There is an alternative way involving a power-in reset, but this
isn't easy and should only be a last resort. Both of these methods are
covered in the OP hardware manual (you'll have to dig to find them though).

 

Thanks a lot for helping me out.But I found out that we do not have COM TEXT with us anymore.I think its been lost even before i joined this company.So there is no way we can rewrite the program into the OP.

But I've tried checking out what i could without COM TEXT,in the PLC side it is ok,we are still receiving alarms (by means of manual activation cos the system has not been running for years) and when we acknowldge by means of a switch,the alarm disappears from the OP and it does come back when we activate the alarm,but we could not input anything.

Thanks and cheerio

 

The OP15 comes in two generations of product. The first generation version used Comtext. The Comtext version saved the files with a ".o15" extension (other models of OP had different extensions, such as ".020", etc.). The second generation product used Protool.

If your OP15 is a first generation product, I suggest that you contact your Siemens rep and ask for a copy of Comtext. You may try to get this from him for free, as it is an unsupported obsolete product. If you are using the version of Step-5 which works with MS-WIndows XP, you can run Comtext by installing it so that it launches from Step-5. Comtext is a CP/M program that ran in an MS-DOS emulator, that needs yet another emulator to work with MS-Windows.