Mitsubishi Electric MELSEC iQ-R Series User Manual page 302

Locations from which data logging can be performed
Data logging cannot be performed from multiple locations to the same setting number. The CPU module supports data
logging performed concurrently at a maximum of 10 locations assigned to setting numbers 1 to 10.
Retention and clearance of data logging settings
After the data logging is started, the registered data logging settings are latched. Thus, if the data logging is started
(registered) before powering off and on or resetting the CPU module, register the settings again when performing the
following operations to the CPU module; Powering off and on and switching the operating status to RUN; Resetting and
switching the operating status to RUN; Switching the operating status from STOP to RUN.
As a result, data logging can be executed again with the registered data logging setting.
However, the registration of the data logging settings is canceled in the following cases. (The corresponding SM number to
the data logging setting number among relevant special relay areas (data logging preparation) turns off.)
• The CPU module is turned off and on or is reset without an SD memory card that contains the data logging setting file.
• The replaced SD memory card does not contain the data logging setting file and the CPU module is turned off and on or is
* 1
reset.
*1 If the data logging setting file contained in the replacement (new) SD memory card is different from that contained in the replaced (old)
SD memory card, register the data logging setting file contained in the replacement SD memory card.
It is necessary to register the data logging settings again by the user operation of starting data logging in CPU Module
Logging Configuration Tool.
Behavior that occurs when trigger logging is resumed
If data logging is stopped or collection is suspended before the completion of trigger logging and subsequently data logging is
run again, data collection begins from the initial state before trigger logging, rather than continuing from the last time.
Stopping/suspending data logging using CPU Module Logging Configuration Tool
After data logging is stopped or suspended from CPU Module Logging Configuration Tool, all the data in the internal buffer are
saved into the target memory. If a small number of records or a small file size is specified as part of the storage file switching
condition, saving data to the target memory may take longer.
Error that occurs when the data logging is started
Behavior when an error occurs at the start of the multiple data logging settings at the same time is as follows:
• If the start operation is performed by using CPU Module Logging Configuration Tool, the CPU module runs data logging for
the setting files that have been successfully registered.
• If the auto logging is started, the CPU module does not run any data logging session.
Behavior upon change of the internal buffer capacity
When the internal buffer capacity is changed during execution of the data logging function, note that:
• If the internal buffer capacity for the setting number of the running data logging is left empty to disable the capacity, an error
occurs when the data logging is stopped and restarted (write to the programmable controller does not cause an error).
• If the internal buffer capacity of the setting number of the running data logging is changed to a smaller value, data may be
lost when the data logging is stopped and restarted.
20 DATA LOGGING FUNCTION
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20.16 Precautions to Take When Using the Data Logging Function