Peak Flow in RSLogix 5000

adonnell

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• Jun 8, 2010

• #1

I am developing a pump program and need to capture the peak flow that occurs in 1 day. I have the analog input for the flow but I don't know how to capture the highest value of that flow for the day. I also need to capture the time at which the peak flow occurs. Any ideas?

I should use the compare instruction but what should I be comparing? Thanks for your help!

 

brucechase

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• Jun 8, 2010

• #2

This is what I use for a max timer. You can use something similar for any input, and move a 0 into the file at the start of the day.

 

OkiePC

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• Jun 8, 2010

• #3

If the NEW is > PEAK, then set a bit.

Use the bit to MOV NEW to PEAK and to GSV Wallclocktime into your storage locations.

At the end of the day, reset PEAK to zero (or whatever value makes sense).

 

BillRobinson

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• Jun 8, 2010

• #4

User Ladder compares and the MOV instruction


if live_flow is greater than max_flow
then
MOV live_flow -> max_flow and MOV TIME->max_flow_time.

At the end of the day (controller clock or a 24hr timer.dn)

MOV max_flow -> yesterday_max_flow
MOV max_flow_time -> yesterday_max_flow_time
MOV 0->max_flow
MOV 0->max_flow_time

 

adonnell

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• Jun 8, 2010

• #5

Thanks. I am new to PLC programming (I am really an HMI/SCADA guy) and really appreciate the help!

Using GSV DateTime to set PeakFlowTime (a member of a user defined data type), what data type should PeakFlowTime be? I can't find a datetime type.

 

adonnell

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• Jun 8, 2010

• #6

Dint[7]?

 

OkiePC

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• Jun 8, 2010

• #7

Yes, the Datetime attribute and the LocalDateTime attributes are made up of 7 DINTs.

 

gscure

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• Jun 8, 2010

• #8

DateTime DINT[7] GSV
SSV
The date and time in a readable format.
DINT[0] year
DINT[1] integer representation of month (1-12)
DINT[2] integer representation of day (1-31)
DINT[3] hour (0-23)
DINT[4] minute (0-59)
DINT[5] seconds (0-59)​

DINT[6] microseconds (0-999,999)

 

adonnell

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• Jun 8, 2010

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Thanks again!