PLC software question 1

[snorkles]

Situation: 7 year old, motor controlling, mitsubishi PLC has been very reliable. Electrician has installed hardware for monitoring (PC with GX developer). Unfortunatly the project copy which was on a floppy disk has been lost. Question: how does one retreive this project from the plc? AS I understand, we will need a copy of the project for the PC, prior to going online to-PLC, for monitoring ladder diagram etc.
Please advise,
"novice"

 

[controlsdude]

you can still upload the plc without comments. What you will have is a program that is undocumented.

I would go back on the company that originally wrote the program. Maybe they or someone they know has these files backup'd on their server.

If this does not get it. Then your have to look at the physical IO off of the prints document that IO then make up all the documentation yourself for all the functions in the program.

 

[dandydon]

Which Mitsubishi PLC do you have? Some of them (A2A for sure) have the ability to store the instruction comments, etc. in the PLC processor.

 

[JBinCA]

You'll have lost the variable declarations and any comments that were in the original code.

The variable declarations for inputs and outputs can be easily recreated by looking at what's wired to each, but if the code is sufficiently complicated as to require the use of multiple internal bits as well, their purpose will be much more difficult to derive.

I don't expect that a PLC controlling a motor will have a very complicated program.

Controlsdude is right, that it's certainly worth trying to track down the original copy of the code from the vendor.

Best of luck.

JB

 

[snorkles]

Mitsubish's A0J2H CPU is being employed.Maybe 800 rungs.Comments are key.Is the project uploaded from the PLC ROM??