The internal buffer is a system area used to temporarily store collected data.
Internal buffer capacity setting
This setting can be specified using an engineering tool (Page 115 INTERNAL BUFFER CAPACITY SETTING). For
trigger logging, increasing the internal buffer capacity allows for a larger number of data records collected before a trigger and
also helps to prevent processing overflow. If the free space in the internal buffer is still insufficient after increasing the internal
buffer capacity, use the following workarounds:
• Increase the data collection interval or timing.
• Reduce the number of data records to be collected.
• Lower the frequency of file switching.
Amount of internal buffer consumed
This value can be calculated by multiplying "Number of data points" by 2 bytes. Note, however, that additional space is
consumed by columns configured for output, as indicated below:
• Date/time column: 10 bytes
• Data collection interval column: 8 bytes
• Index column: 4 bytes
When data logging is configured to collect as much data as one setting x 128 records and output all of the columns (i.e.,
maximum allowable configuration):
128 × 2 + (10 + 8 + 4) = 278 bytes
Data Logging File
This section describes data logging files.
Storage format of data logging files
The binary file format is available for data logging files. The size of binary file format is small and therefore quicker access to
files is provided. GX LogViewer is also available for displaying data. For details on the output format, format specifications,
and output contents of each file, refer to the data output format. (Page 455 Data output type)
19 DATA LOGGING FUNCTION
19.7 Internal Buffer