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Shaun_Harrison

Alpha 2 remembering outputs after powering down

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Hi,

 

I have supplied a AL2-24MR-D PLC for a customer to control a swimming pool lid, they're still setting it up at the moment and it generally works, they are adjusting the set points of inputs to get a smooth operation, however, after powering down half way through a cycle, they are powering up and the PLC is remembering one of the outputs, they are several hundred miles away so it is difficult to visit and investigate myself, but they say they have killed the 230V power supply going to there control panel, which has the 24V power supply inside, left it for some time and powered back up but it has remembered one of the outputs.

 

This output is on a set-reset which is set by a counter, following a power down we want to return to the start of the program, all counters at 0... etc, I'm sure this was happening when I tested it but from the reports from site its not happening now.

 

Any help on how to reset the controller would be appreciated.

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Seems to me, you would wan to use the first scan bit to reset the counter.

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