Operating Conditions - YOKOGAWA GX20 User Manual

1.9 Configuring Logic Math (/MT option)
Description
1-108
The internal switch or relay output is 0 when the calculated result of logic math is as follows
(or 1 otherwise).
• When the calculated result is greater than –0.5 and less than 0.5
• When the calculated result is in error
Operation Interval
Computation and updating of the output operate at the scan interval. However, if the scan
interval is less than 100 ms, it runs at 100 ms.
If the measurement mode is set to dual interval, logic math runs according to the master
scan interval.
Starting
Operation starts when the logic math setting is changed to a value other than off. It is not
affected by the starting and stopping of math, recording or control.
About the Logic Math Data (LM)
Logic math data is used when you want the result of a logic math operation to be reflected
in the operation of another logic math number in the same period. The function returns a
1 when the logic math operation outputs a 1 and 0 when the operation outputs a 0. The
function also returns a 0 when the output type of the specified logic math number is set to
Off.
The data cannot be used in the calculation expression of a math channel.
LM values are retained only during the same scan interval.

Operating Conditions

The relay (DO channel) values used in logic math are displayed values (values that reflect
energized or de-energized).
Logic math is applied to the internal switches and relays (DOs) after the next interval. If you
want to reflect the results of logic math within the same interval, use logic math data (LM).
Example: Differences in the logic math results depending on the calculation expression
Logic math
number
Settings LM01
LM02
LM03
Results First interval
Second interval
Third interval
If multiple logic math operations set the same output, the result of the logic math with the
largest logic math number is reflected. However, for the logic math data (LM), the calculated
result of that number is reflected.
Output
Output type Output No.
Internal switch 1
Internal switch 2
Internal switch 3
Internal switch
1
Internal switch
2
Internal switch
3
Internal switch
1
Internal switch
2
Internal switch
3
Internal switch
1
Internal switch
2
Internal switch
3
Calculation expression
Setting 1 Setting 2
W001 W001
S001 LM01
S002 LM02
1 1
0 1
0 1
1 1
1 1
0 1
1 1
1 1
1 1
IM 04L51B01-01EN