Mitsubishi Electric MELSEC-L Series - Checking the Processing Time; Checking the Data Logging Processing Time

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CHAPTER 10 PROCESSING TIME
10
10.2 Checking the Processing Time 10.2.1 Checking the data logging processing time
10.2 Checking the Processing Time
Data logging is the best-effort type
*1
function.
*1 The concept of obtaining the maximum performance from the condition at the time
Logging may not be performed at the specified sampling intervals because processing time may vary depending on
the configuration or other connected devices. After configuring the system, thoroughly examine the processing time
before starting the system operation.
The following figure shows the process from data collection to file output.
This section also describes what is the point when checking the time required for the following processing.
10.2.1 Checking the data logging processing time
Check that all the data sampled by data logging (continuous logging) have been processed. The following shows the
information to be checked and corrective action to be taken if an error is detected.
For the numbers of the special register, refer to Page 147, CHAPTER 12.
Processing Description Check point Reference
1) Data logging processing
Stores the data accumulated in the buffer to a data logging file.
If the data logging processing cannot keep up with the speed of
the sampling processing, a processing overflow occurs and
some data will be missing.
Check that all the data sampled
have been processed.
Page 143, Section 10.2.1
Information to be checked Corrective action
Check the value in the special register (Processing timeout count).
(If the special register value is other than "0", the data logging
processing (file saving) does not keep up with the processing speed of
the target data.)
Perform any of the following:
• Increase the sampling interval. ( Page 99, Section 8.4.4)
• Reduce the number of sampled data. ( Page 101, Section 8.4.5)
• Increase the buffer capacity. ( Page 115, Section 8.5.2)
• Decrease frequency of file switching. ( Page 109, Section 8.4.10)
Check the following after taking a corrective action.
• The value in the special register (Processing timeout count) is "0".
• The value in the special register (Free buffer space) does not drop to near "0" with
time.
Data
Device
Buffer
Data logging
CPU module
1)