Weird issue with SLC5/03 CPU

Hi,

I have a customer in Honduras that recently modified a program on a machine with and SLC5/03 CPU. He claims that the new program works fine as long as the computer is online with the processor. But as soon as they go offline or disconnect the comm cable the program will not run correctly. They claim that one of the outputs just programmed will not work. The rest of the program seems to work fine. They cannot see any faults and cannot monitor the program since as soon as they go online the output starts to work. Is this even possible? I had them change the processor to a newer one and the problem persists. Any suggestions greatly appreciated.

I've never heard of THAT one before ...

the inevitable question: can you post the RSS file? ... (you'll have to ZIP it first - forum rule) ...

mandrake said:

They claim that one of the outputs just programmed will not work.

Click to expand...

Can you define "not work"? Stop turning on? Stop turning off? Other?

mandrake said:

The rest of the program seems to work fine. They cannot see any faults and cannot monitor the program since as soon as they go online the output starts to work. Is this even possible? I had them change the processor to a newer one and the problem persists. Any suggestions greatly appreciated.

Click to expand...

The only impact that a programming terminal can have on a system to my knowledge:
1) Slight increase in overall scan time is possible with potential for spikes in the scan time. This is rarely an issue with real equipment and may be undetectable unless the system is heavily loaded.
2) The active node table bit for the programming terminal will change from a 0 to a 1 on DH+ and DH485 systems when the terminal is a new device on that channel. If the node table bits are used in ladder logic, this could have a real effect.
3) The comms active bit may change from a 0 to a 1 for the channel to which the programming terminal is connected if there are no other devices on that channel. This only matters if the comms active bit is actually used in ladder logic.

Are they assembling the edits before going offline?
Are they power cycling the SLC or operating the keyswitch when going online?
Is the SLC fitted with an EPROM memory module?
Can you post a copy of the program here (zip it first)?

And if you post the program, please point out the output in question.