3.2 Function Modules
3.2.5 Data Logging
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Set the data sampling rate.
Set the data sampling period.
Specify the value and unit to control whether data is sampled every scan or once in more
than one scan.
To sample data every scan, specify the same value as the scan set value.
Specify whether data is to be logged synchronized or asynchronized with the scan.
Refer to the following section for guidelines on scan settings.
to Set the logging conditions using items
to .
Setting
Description
High-speed scan
Samples data synchronized with the high-speed scan.
Data is sampled immediately after completing execution of the DWG.H lad-
der program.
Low-speed scan
Samples data synchronized with the low-speed scan.
Data is sampled immediately after completing execution of the DWG.L lad-
der program.
Setting
Description
Merits
Demerits
Synchronous
scanning
Data is written to
the log synchro-
nized with the scan
No data is lost.
This creates an overhead on the scan
and can cause Watchdog Errors (E.001),
or cause the CPU Module to go down.
Asynchronous
Scanning
Data is written to
the log asynchro-
nously with the
scan.
There is no over-
head on the scan.
If the scan setting is set to a fast rate or if
the idle time of the scan is low, logging
can fall behind or data can be missed if
there are too many data points to sam-
ple.
No.
Item
Description
Specify the start
timing
If the check box is selected, register operation will control when logging
starts. If conditions are set in items
and , logging will start when
these conditions are met.
If the check box is cleared, logging will start according to manual opera-
tion of the button displayed by the MPE720.
Specify the stop
timing
If the check box is selected, register operation will control when logging
stops. If conditions are set in items
and
, logging will stop when these
conditions are met.
If the check box is cleared, logging will stop according to manual opera-
tion of the button displayed by the MPE720.
Add detailed out-
put conditions of
data
•
If no detailed output conditions are specified: Clear the check box.
•
If detailed output conditions are specified: Select the check box and
specify the conditions for items
, , and
. Logging will start when
these conditions are met. Even if logging stops when the output condi-
tions are no longer met, it will start when the conditions are met again.
Start condition
Specify any S, M, G, I, or O register, and numeric value.
The start condition is when the rising edge is detected (when the register
changes from OFF to ON).
The stop condition is detected by the state of the register. (If the register is
ON, the condition is always detected.)
Stop condition
Condition A and
Condition B
Specify any S, M, G, I, or O register and numeric value.
If a condition is entered for both condition A and condition B, specify the
condition at ( ).
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