Heidenhain 355 and error 83 (PLC: logic assignment missing)

Hello,
My friend has a machine with Heidenhain 355 and when he tries to start it, he gets Error 83. I found description of this error:

83
PLC: logic assignment missing
Cause of error:
PLC syntax error: A logic operation was performed,
but the result was assigned to a new logic operation
instead of to an operand.
Corrective action:
Edit the PLC program.

Can anyone tell me more about this error, what is source of the problem and what is probably solution? What should I looking for in program?

Machine name is Stankoimport SMO-32.

Did anyone met with that error 83?

Can anyone tell me more about this error, what is source of the problem and what is probably solution?

Click to expand...

I am not familiar with your machine, but "reading between your lines", the souce of the problem is most likely the last or most recent change that was made to the program (assuming that it once worked without this Error Message 83). Search for changes, or compare this version of the program to an older version to find the changes.

What should I looking for in program?

Click to expand...

Look for a logic operation where the the result of the logic was assigned to a new logic operation, instead of to an "operand". That is probably techo-babble writing, the equivalent of "you made a typographical error in a logic expression, dummy, most likely in the Output of a logic operation"!

(No dis-respect intended. Computers always talk down to me, too!)

Here are some links I found with Google, maybe something there will help:
http://www.heidenhain.com/en_US/documentation-information/software/downloads/
http://www.heidenhain.com/en_US/documentation-information/documentation/

http://www.heidenhain.us/?wm_crID=7...WW8bYCFQFp4AodWDkADQ&wm_kw=heidenhain&wm_sd=1

I think this is the link to the Heidenhain TNC 355 Operating Manual.
http://content.heidenhain.de/doku/o...tml/de/index/N12DA1/N14543/N147DB/N147DB.html
On Page P-35 (Page 76 in the PDF file), this manual says:

"Variable auxiliary functions. Variable auxiliary functions are defined by the machine manufacture and explained in the machine Operating Manual."

(M83 is one of the variable auxiliary functions on the folllowing list, as are all M numbers from M31 to M88.)