Hidden code in Omron CPM1A

[kokko 0]

I've got a problem with Omron Sysmac CPM1A-40CDR-D. My machine controlled by cpm1a doesn't make all programmed moves like before. I suppose PLC is a cause. I thought that some instructions in code hangs or malfunction, so I have connected PLC to PC, imported instruction set code into Syswin 3.4 and analized. Seems like some code doesn't display. Ladder that is displayed is not complet. I was told that a software producer may hide some code, provides himself monopoly for repair service :) So my question is: How can I check is there a hidden part? How can I view hidden code? Thank you in advance for any help.

[Jay Anthony 118]

There is no way to hide code. The incomplete ladder is shown in mnemonics or statement language.

[Sleepy Wombat 27]

The catch cry of MR PLC ... "the program never fails". my guess is either you have a problem with a sensor which is an input to the PLC that is not firing the logic to control the output. or you might have a faulty output... ie the relay output of the PLC has blown due to the loading being exceeded... or the device you are controlling has failed... with the CPM you either have access to the PLC code or you don't, and as Jay pointed out, in the CPM you cannot hide code...

[Homer_BL 2]

In Syswin, there in an option "Upload untill first end instruction". Maybe you did not uploaded SUBs (SUB are written after the program end).

[Jay Anthony 118]

(SUB are written after the program end). Not true SUBS are written just before the END.

[Sleepy Wombat 27]

Syswin gave you that option. because as I recall, you could use a hand held programmer and edit the program and insert an end instruction before the very end of the program. This code after the END was never executed, and if you uploaded into syswin then try to download (with two end instructions) you would get a compile error.

[kokko 0]

I think exactly the same. Problem happend after relocate machine to other building. That's why i want to track the reason by analysing ladder in the run. Edited 31 Jul 2012 by kokko

[Sleepy Wombat 27]

If the PLC code is password protected as set in syswin, when you try and connect to the PLC, you will have a dialogue pop up stating that the program is pass word protected.. you cannot see any code if it is PW protected. The programmer had to set this with syswin and is enabled with a FNU 49 call in the first line of the PLC logic.