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MAP · Posted: 19/09/2017 18:25 Post subject: Micrologix 1200 PLS configuration

Have a Micrologix 1200 plc, configured HSC:0 for PLS operation. Set a 3 element control as follows;
PLS10:0 = 250, Output Bit Pattern = 0000 0001 0000 0000
PLS10:1 = 500, Output Bit Pattern = 0000 0010 0000 0000
PLS10:1 = 750, Output Bit Pattern = 0000 0000 0000 0000

Proper Operation
HSC:0.ACC begins counting pulses, at 250 pulses, output 8 turns on, counter continues accumulating counts, at 500 pulses, output 8 turns off, output 9 turns on, at 750 pulses, output 9 is turned off, counter is reset and begins counting up from zero again.

What actually is happening is the counter is counting up to 250, turns on output 8, resets to zero and counts up to 500 where it turns off output 8 and turns on output 9, resets to zero and counts up to 750, turns off output 9, resets to zero and counts up to 250 again. Initial sequence is repeated. Can anyone provide assistance with this issue, thanks.

MAP · Posted: 20/09/2017 21:41 Post subject: Micrologix 1200 PLS configuration

parcell
Finally got it figured out, the description that I provided is exactly how it is designed to work. If you want to turn on an output at 250 counts and turn it off at 300 counts, you must do the following;
PLS10:0 = 250
PLS10.1 = 50
The PLS will increment to 250 counts, turn on an output, resets to zero and starts counting up to 50, when it turns the output off. definitely not like a hardware PLS, but it does work. I set up a test demo where I am controlling 4 outputs.