Internet PLC Forum
General => Technical support => Topic started by: asitsaha on May 14, 2014, 05:23:23 AM
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How to create a totalizer for analg channel for nano-10 PLC? Is there any integrate function to achieve this ? Also any function to get the exact execution time of one cycle of ladder program
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You can always use a 32-bit variable keep the cumulative values.
E.g.
A = A + ADC(1)
A will increment each time the above statement is run and a new ADC reading is captured. You can then compute the average readings.
E.g.
A = 0
FOR I = 1 to 100
A = A + ADC(1)
NEXT
B = A / 100
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I want to totalize an analog channel value. Let us assume , we have have a gas flow rate signal (m3/min) connected in a analog channel. We want to inetgrate that flow rate and find the actual gas consumed.
Hence we need to add
Total = Total + ADC(1) * Scan time of program
How to I get the scan time of program in milli second ?
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Two suggestions for measuring time between ADC readings:
1. Use ladder logic to call your integrate special function based on a clock signal. Say every 100ms. This way the period between ADC readings is fixed.
2. Use the status(21) function to return a raw CPU time at each ADC reading. You can then compute the time from the previous reading.
Gary d