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vinigusto · Junior Joined: 16 Aug 2017 Posts: 2

Hello guys,

I'm having an incremental encoder, HS351000934B7 Dynapar Brand with 1000 PPR, installed on the client coupled to a pulley. I need to calculate the speed of paper passing through this pulley in meters / min on the Micro850 PLC. My idea is: Measure the diameter D of the pulley and calculate the perimeter with the following formula: 2 * pi * R = D * pi which would correspond to X meters for 1 revolution. In the PLC I calculate in 1 minute how many revolutions it gave and would multiply by the factor previously calculated (X meters per revolution) and find the speed. Is the rationale the same?
Has anyone else already implemented a HSC on the micro850 for this situation?

Best Regards,

ynham · Junior Joined: 28 Jun 2018 Posts: 1

Micro850 PLC HSC
All HSC cmds (=1/2/3/4) are Level triggered.
If user wants to reset the ACC then continue the counting, user need to trigger the HSC cmd = 4 once only.
If the HSC cmd = 4 is enabled forever, then it seems HSC stops. (This is the same as MicroLogix) HSC Cmd = 4 (reset) will not stop HSC counting, but set the ACC value to the value in HSC AppData.Accumalator value.
So, HSC cmd = 4 can be used when HSC is counting. (If HSC is counting when HSC cmd = 4 is issued, some counting may be lost.) (This is the same as MicroLogix) HSC AppData.Accumalator value will be updated automatically by HSC mechanism, having same value as HSC Sts.Accumulator.
During counting, if the user wants to set one specific value to HSC ACC, user needs to write the value to HSC AppData.Accumalator immediately before HSC cmd = 4 is called.
For HSC Cmd = 1, it will start the HSC mechanism.
Once the HSC is started, HSC is in Running mode. At this time, if user turn the HSC FB "Enable" input to False, the HSC counting is still going on.
To stop HSC counting, HSC cmd = 2 need to be called at least once.
To reset the accumulator, user must set the following logic:

HOW TO CALCULATE VELOCITY INCREMENTAL ENCODER using MICRO850

HOW TO CALCULATE VELOCITY INCREMENTAL ENCODER using MICRO850

What you have to do:
Set a timer let say 1, 2, 3, 4, 5 seconds (depends on the speed for not reaching the Higher Counter Limit but lower is better) and count the impulses on that time, Reset and start the counter after each 1(2 3 4 5) sec applying the mathemathical formulas you've already described for speed calculation..