Mitsubishi Electric MELSEC iQ-R Series User Manual page 303

Trigger condition at the start operation of data logging
Ensure that the trigger condition is not met during the registration of the data logging settings by the start operation of data
logging. If the trigger condition is met, the data logging settings cannot be registered.
When file register is specified as device in condition specification
After registering data logging, do not change the file name of the file register file and the block No. of the file register when the
file register is specified for the condition specification in the collection and trigger condition settings. Doing so may possibly
result in failure to successfully collect data logging results.
When the data collection condition is set to "Time specification"
If "Time specification" is selected for the data collection condition, data collection is performed as an interrupt processing
operation and therefore special care should be taken when configuring the data collection interval, the data collection timing,
and the data logging processing time per scan. In the following cases, scans may take a longer time, possibly resulting in a
WDT error:
• The collection interval and the collection timing are so short that data logging is frequently performed during a single scan.
• The data to be collected is so much that the data logging processing time per scan is long.
Numbering of the storage files used during data logging
■If one or more numbered storage files already exist in the file storage folder
The new file is given a file name that uses a number incremented by one from the highest number among the existing files.
■If one or more storage file folders exist but no storage files in them
A new file is stored into a folder with the lowest number and given the same number as the folder.
However, if there are 258 or more folders, a new folder is created and the file in it is given the same number as the new folder.
Behavior that occurs while collected data is stored in the target memory
If one of the following operations is performed while collected data is stored in the target memory, any unsaved data is cleared
and not reflected to the results:
• Powering off and on the CPU module
• Reset
If one of the following operations is performed, unsaved data continues to be stored in the target memory:
• Changing the operating status of the CPU module from RUN to STOP
• Suspending the data logging by turning on of the special relay areas SM1312 to SM1321 (Data logging setting No.1 to 10
Data logging suspend/resume flag)
• Stopping/suspending data logging from within CPU Module Logging Configuration Tool
• Issuing the LOGTRGR instruction
Creating files and folders
Under the "LOGGING" folder that contains data logging setting files and data logging files, do not attempt to create files or
folders using a personal computer or other device. Doing so may result in deletion of files and folders.
When collection is performed at the specified time
When "Time specification" is selected for the data collection condition and the collection at the specified time is selected
rather than data collection during the END processing, check the collection interval by referring to the information reported in
the collection interval column. Do not rely on the information reported in the date/time column because it may be incorrect due
to clock accuracy error.
20.16 Precautions to Take When Using the Data Logging Function
20 DATA LOGGING FUNCTION
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