Micrologix random bits
Micrologix random bits
(OP)
Has anyone experienced this problem? We seem to have a recent problem with the MicroLogix 1500 LRP processors. Randomly, we have had unused bits go high and integer values re-write themselves. In one instance, the first 20 timer presets in the program all reset themselves to 0. We have the EEPROM set to load on memory error only and the presets should all be burnt in during commissioning.
We have had some process error bits in the program reserved for future use. They had neither OTE or OTL instructions referencing them. When they randomly go high, the customer has no way of resetting them except disconnecting the battery and forcing the EEPROM to load.
Of course the Rockwell tech people always tell you it's not them. They think it might be our Parker CTC touch screen driver. This only started showing up recently.
We have had some process error bits in the program reserved for future use. They had neither OTE or OTL instructions referencing them. When they randomly go high, the customer has no way of resetting them except disconnecting the battery and forcing the EEPROM to load.
Of course the Rockwell tech people always tell you it's not them. They think it might be our Parker CTC touch screen driver. This only started showing up recently.





RE: Micrologix random bits
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TW Controls - http://www.twcontrols.com
RE: Micrologix random bits
RE: Micrologix random bits
The bits in question are not addressed in the touch screen program and they do not have trigger coils in the PLC program. In one instance, the first 20 timer's (T4:0-T4:20) presets reset to 0. We have no use or desire to even change the presets through the screen or program.
I was wondering if anyone else has experienced the phenomena of bits or presets changing without being told to. Of course when you call Rockwell tech support, the standard greeting is. "Rockwell tech support, what did you do now? It's your fault!" They tried blaming it on our touch screen since it wasn't their’s. If the problem were in our programs, it would do it on all of the machines, not just a random few. Is a batch of bad processors possible?
RE: Micrologix random bits
RE: Micrologix random bits
That being said, the timer presets that went to 0 WERE hard coded. And why did the unused bits go high? Perhaps cosmic rays??