Mitsubishi Electric MELSEC-L Series User Manual page 74

(4) Availability of data logging
Data logging can be executed through another station or a serial communication module on the network.
For the same setting number, however, simultaneous execution by multiple routes is not allowed.
(5) Execution of data logging
Once data logging is started, it can be executed only with the memory where the setting file of the currently
executing data logging is stored. (A data logging setting file stored in a different memory cannot be used.)
(6) Start operation after stop of trigger logging
When data logging is restarted after stop or temporary stop of data logging before completing trigger logging, data
are collected from the initial status before the trigger.
(7) When data logging registration failed
If a part of multiple data logging settings fails to be registered, successfully registered data loggings only will be
executed. Note that, however, registration by auto logging is different in operation.
( Page 75, Section 7.2 (2))
(8) Sampling interval setting in "Sampling"
When "Time specification" is set for the sampling interval in "Sampling", sampling is executed as interrupt
processing. Therefore, scan time will be extended and a watchdog timer error may occur in the following cases.
• Short sampling interval and many data logging executions per scan
• Large volume of data to be sampled, and long data logging processing time
(9) Checking the sampling interval
Depending on the accuracy of the clock, some errors may be observed in the information output to the "Date"
column. Check the sampling intervals with the information output to the "Sampling interval" column. For the
accuracy of the clock, refer to the following.
MELSEC-L CPU Module User's Manual (Hardware Design, Maintenance and Inspection)
(10)When a file register is specified
When a file register is specified in "Device specification" in "Sampling" or "Trigger", do not change the block
numbers and file name of the file register after registration of the data logging. Doing so may disable normal
collection of logging results.
(11)Sampled data being saved to an SD memory card
If the CPU module is powered off or reset while data in the buffer is being saved to an SD memory card, unsaved
data will be cleared. However, data will be saved without being cleared in the following cases.
• Status change from RUN to STOP
• Pause caused by turning off the special relay (Data logging start)
• Stop or pause operation from the configuration tool
• Execution of the trigger logging reset instruction (LOGTRGR)
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