1 sec pulse bit running up my ADD instruction to fast

Snap25

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Objective :

Once the inlet flow drops below the set point on the filter chamber it starts a cleaning sequences and flushes the filter with pulses air and water to break up the solids that are building up on the sleeves.


Logic to control how many pulses to run to flush each sleeve :

I'm using a 1 second pulsing bit created from the status files to add up my pulses with an ADD and LEQ instructions.

Every time it pulses it is supposed to add 1 to the ADD destination but during that "1" second when it pulses, it adds up more like 8! The rest of the logic works correctly but I'm just not getting the pre set amount of pulses to clean each sleeve because its accumulating more than 1 in that one second pulse!!


Am I going about this the wrong way?
 
Ok what triggers your sec pulse?
Not sure if the ML1100 supports theses but maybe look at the S:4/6 bit or use the STI if you need a precise sec pulse
 
You need to use a one shot after the status bit before the add
this will allow only one pulse to the add per 2 second if you have
used the status bit that changes state ( 0 or 1 ) at that rate

Without the ons or osr
what you are probably seeing add up is the scan rate
or it maybe the bit you selected is the one eighth of a second
move it up three more bits
 
Last edited:
Ok what triggers your sec pulse?
Not sure if the ML1100 supports theses but maybe look at the S:4/6 bit or use the STI if you need a precise sec pulse


I'm using the one second bit from the status file. I thought the one second timer seemed pretty accurate but I guess not because during that 1 second it makes the run true, it adds around 8 instead of 1 to my add instruction.
 
Objective :

Once the inlet flow drops below the set point on the filter chamber it starts a cleaning sequences and flushes the filter with pulses air and water to break up the solids that are building up on the sleeves.


Logic to control how many pulses to run to flush each sleeve :

I'm using a 1 second pulsing bit created from the status files to add up my pulses with an ADD and LEQ instructions.

Every time it pulses it is supposed to add 1 to the ADD destination but during that "1" second when it pulses, it adds up more like 8! The rest of the logic works correctly but I'm just not getting the pre set amount of pulses to clean each sleeve because its accumulating more than 1 in that one second pulse!!


Am I going about this the wrong way?

It sounds like your 1 second pulse is staying true for more than one scan of the processor. Use something like an OSR to make sure that it is only on for one scan.

However, if you are only trying to count seconds, you could start a timer and use your compare statement with the .ACC of the timer. You won't actually use the timer, just use the Accumulated value to count seconds.

This is off the top of my head, I don't work with A-B processors as much as I used to.
 
It sounds like your 1 second pulse is staying true for more than one scan of the processor. Use something like an OSR to make sure that it is only on for one scan.

However, if you are only trying to count seconds, you could start a timer and use your compare statement with the .ACC of the timer. You won't actually use the timer, just use the Accumulated value to count seconds.

This is off the top of my head, I don't work with A-B processors as much as I used to.

I'm going try putting an OSR bit first and go from there. That should do it.. I don't know why I didn't think of that!
 
Depending on how low the cleaning cycle last you could use a counter instruction instead of an add instruction. A counter only increments on a false to true transition. The add instruction adds each scan while rung is true.
 
Use the pulse bit to trip a counter, not an add instruction. The counter only increments up on a change of status, not every scan.
 
Objective :

Once the inlet flow drops below the set point on the filter chamber it starts a cleaning sequences and flushes the filter with pulses air and water to break up the solids that are building up on the sleeves.


Logic to control how many pulses to run to flush each sleeve :

I'm using a 1 second pulsing bit created from the status files to add up my pulses with an ADD and LEQ instructions.

Every time it pulses it is supposed to add 1 to the ADD destination but during that "1" second when it pulses, it adds up more like 8! The rest of the logic works correctly but I'm just not getting the pre set amount of pulses to clean each sleeve because its accumulating more than 1 in that one second pulse!!


Am I going about this the wrong way?

You need to add ONS instructions before your ADD instructions. What's happening is the Status file Pulse bit stays on for more than one scan, so whenever the pulse bit is on, it will add 1 to your total every time that piece of logic scans. Certain instructions, like CTU and CTD have this built in and only execute on false-to-true transitions, but that is not the case with arithmetic instructions. Either use a CTU instruction instead or add a ONS.
 

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