RSLogix 5000 "Unspecified Communications Problem"...

At a customer right now, trying to upload the program from a CompactLogix 1769-L32E/A processor (with v15 firmware). RSLinx see it fine, and the controller is named. When I try to upload, I can get to the 'Create Project and Upload?' prompt, but as soon as I click Yes, it goes offline and I get the attached error message.

In RSLogix, I get 'completed with 0 warnings and 1 error'...

Error - No project in controller

I think there is a program in it, since the 'RUN' light comes on, but I'm not sure.

Any ideas???...



-Eric

Have you got V15 software installed on your PC ?


And yes, you can put a processor with no program in it into RUN mode.

Apparently, the program was indeed missing. Thankfully, the customer had an identical machine WITH a program, so I was able to upload that one and use it in this machine.

Good to know about the RUN mode with no program. Thanks!... :site:



-Eric

I may have misled you.... you can put a processor into RUN with a BLANK project (i.e. no code), but a processor with NO project ? I've never tried to do this, so I will have to give it a go, see what happens (tomorrow, if I'm not too busy). Although your posts suggests you can.... hmmm

yep ... the lights are on - but there's nobody home ...

from the "secret handshake" department ...

with CompactLogix and ControlLogix the processor's OK and Run LEDs can both be on steady green - even with ZERO program loaded ... see page 131 ...

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um011_-en-p.pdf

imagine how confusing that is to an untrained maintenance tech - or even worse - to an operator just trying to recover after a power failure with a dead processor battery ...

(A) the OK light is on ...
(B) the Run light is on ...

so WHY on earth won't the machine run? ...

.

Totally agree with your "secret handshake" Ron, except that a "Project" does not have to have any configured I/O !

The other option for the I/O LED to be off is shown on your pic..... "There are no devices in the I/O configuration of the controller".

It could, for instance, just be collecting production data from a number of processors and storing it to CompactFlash, or it could be the "Master" recipe data server for a number of processors. Either of those scenarios could be accomplished using explicit pathing in the message instructions, or the other processors could be doing the messaging, so no I/O configuration is needed.

But i will say it is extremely rare for this to be a possibility, so, no IO LED means "No Project" in the vast majority of cases.

There's always that "gotcha" though, there's always one, lol

Ron Beaufort said:

imagine how confusing that is to an untrained maintenance tech

Click to expand...

and me!...

I'm used to PLCs that shine something like a red ERR light when there is no program...

I spent about an hour trying different things before I posted. I tried Ethernet and serial ports with the same result. If I didn't have a 'spare' machine to test, I would still be scratching my head as to why the RUN light was on...

By the way, the I/O light was definitely illuminated green on this processor. Oh, and the BAT light is off, so I don't know why the program disappeared in the first place. Perhaps it wasn't 'gone', but just corrupted?

In any case, as soon as I downloaded the 'replacement' program, the machine fired right up!

Thanks again for the help, guys!



-Eric

Eric Nelson said:

By the way, the I/O light was definitely illuminated green on this processor.
-Eric

Click to expand...

In that case it had a project in it, with configured I/O, and the controller was communicating with that I/O successfully.

So, I conclude we will never know the real reason why you couldn't upload it.

Sorry my English is no good...
I have the same error message, but in this case the machine is working right now ok. but I can't go online and modify the program.



And the error

Error: Too many online changes have been made to the controller to allow the system to correlate with the open project.

Any idea?? Thanks

facing the same issue