Yokogawa Button Operated MV2000 - Manual (Page 93)

3-19 M-4660
Measurement Channels and
Alarms
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App
Index
• Example 3: Reset if the Pulse Sum Exceeds a Set Value
If the pulse sum exceeds a set value (the reset value), reset the sum and carry over
the value that exceeds the reset value. Count the number of resets, and calculate the
total pulse sum.
Calculation Expression
This table shows which calculation expressions to assign to which channels and what
constants to set.
Channel Calculation Expression Description
101 ((102+P01).GE.K01)+101 Number of pulse sum resets
102 CARRY(K01):TLOG.SUM(P01) Pulse sum
103 K01*101+102 The total pulse sum
Variable Description
P01 The number of pulses per scan interval.
K01 A constant. The reset value. Values that exceed it are reset.
0 0 1 1 1 2 2
P01
Number of pulses
per scan interval
102ch
Sum value
101ch
Reset count
Pulse input
Scan interval
Time
K01
Reset value
(Resets the value below the reset value)
(Sum)
Channel 101: Reset Count
Calculates the number of pulse sum resets.
((102+P01).GE.K01) returns a value of 1 when the value of the previous pulse sum
(102) + the current pulse count (P01) is greater than or equal to the reset value
(K01). Otherwise, it returns a value of zero. The value of Channel 101 increases by 1
whenever the pulse sum exceeds the reset value.
Channel 102: Pulse Sum
Calculates the pulse sum.
This channel normally calculates the pulse sum, TLOG.SUM(P01). If the pulse sum
goes above the reset value (K01), the excess value is set as the new pulse sum.
Channel 103: Total Pulse Sum
This channel multiplies the reset value (K01) by the reset count (101) and adds the
pulse sum (102) to get the total pulse sum.
Note
• Computation starts with the smallest channel number at every scan interval. If a channel
number in a calculation expression is greater than or equal to the number of the channel
that contains the expression, the previous computed result (the previous value) of the
channel with that number will be used in the expression.
• Because the computation function uses single-precision floating-point representation, we
recommend that you set the reset value below 10 7 .
• The MV will not compute values correctly if the pulse input value of a scan interval is larger
than the reset value.
3.10 Counting Pulses (/PM1 option)