YASKAWA SGD7C-***AMAA*** Product Manual page 586

12.1 Data Logging
12.1.2 Scan Setting Guidelines
This timing chart illustrates the logging process when performed synchronously with the scan.
High- peed
or
low- peed can
The logging processes for sampling the data and writing it to a file are performed within the
scan cycle. Therefore, the scan cycle (time period A in the above chart), must be set to a value
greater than the current scan time (time period B in the above chart).
If the scan cycle is shorter than the current scan time, a scan time over limit error will occur and
the count of SW00044 (H Scan Exceeded Count) or SW00046 (L Scan Exceeded Count) will
be incremented. This can also cause a Watchdog Timer Error (E.001) or cause the CPU to go
down.
Set the scan time so that it is long enough to log the number of registered data items.
If Logging Is Asynchronous with the Scan
The scan setting for logging asynchronously with the scan should be set as given below.
Built-in RAM disk
USB memory
Note: These values are for word data without an application. Set the scan setting according to the application
usage conditions (number of registers to log, register types, ladder programs, etc.).
12-12
B: Current can time
DWG.H or Logging
DWG.L (data ampling)
Thi proce ample
target data and load it
into a logging buffer.
Storage Location
A: can cycle
Logging (file writing)
Thi proce write data
that wa ampled during
the can to the log file.
Scan Setting Guideline
0.250 ms min.
0.500 ms min.
Logging Logging (file writing)
DWG.H
(data ampling)