Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual page 220

■File transfer processing time
The file transfer processing time differs depending on the Ethernet line load ratio (network congestion), the operating status
and system configuration of other communication functions.
■Communications during the data logging file transfer
Since the Ethernet communication load is high during the data logging file transfer, the behavior is as follows.
• When other communication functions such as MELSOFT connection and SLMP communications are executed using UDP,
data may be lost at UDP reception and timeout and other errors may occur. Use TCP for communications while this
function is executed.
• When other communication functions such as MELSOFT connection and SLMP communications are executed, their
completion are delayed.
■A data logging file with a file transfer error
If a communication error, a file access error, or a file transfer stop error occurs during the file transfer, the data logging files
being transferred may remain in the FTP server. Do not refer to those data logging files since the data is not guaranteed.
(Data logging files in which a file transfer error has occurred can be checked in the file transfer error history.)
■Data logging stop operation at logging out from the FTP server
Even when the data logging file is transferred successfully, a data logging file transfer error occurs if the operation to stop data
logging file transfer function is performed before logging out from the FTP server or logout fails.
■Timing for DNS setting
To enable the DNS setting, the CPU module needs to be powered off and on or reset. Therefore, when DNS is set during
logging, data in the function memory is deleted if the function memory is specified as the data logging file storage destination.
Configure the DNS setting before the logging starts.
■When the function memory is specified for the data storage destination
When the function memory is specified for the data storage destination, do not power off or reset the CPU module until the file
transfer is completed. Doing so deletes all the data logging files which have not been transferred (standby) in the function
memory.
■File access during the data logging file transfer
• Do not read files in the SD memory card during the file transfer. The transferred files can be read from the server. If a data
logging file in the CPU module is read by using GX LogViewer during the data logging file transfer, the file being read may
be deleted by the setting to delete the transferred files and a file read error may occur.
• When a file is accessed (read/write) during the data logging file transfer, the completion for the file access may be delayed
depending on the number of files.
■Starting data logging during the file transfer
Since the data logging of the same setting number cannot be started during the file transfer to the FTP server, start data
logging after completion of the file transfer. Otherwise, an error occurs at the start operation of data logging.
11 DATA LOGGING FUNCTION
218
11.16 Precautions to Take When Using the Data Logging Function