Appendix; Appendix 1 File Size Of Display Data And Event Data - YOKOGAWA GX20 User Manual

Appendix

Appendix 1 File Size of Display Data and Event Data
File Size
IM 04L51B01-01EN
This section explains how to calculate the file size of display data files and event data files.
The calculation examples are given for the display data only and event data only cases. If
you are recording both display and event data, calculate the data size of each and add them
together. Use the calculated file size as a rough guide.
The calculations discussed here apply to a GX/GP without the advanced security function
(/AS option) or a GX/GP whose advanced security function is disabled.
A file consists of the following data.
Information other than the sampled data + the sampled data + system information
The size of system information can range from 1 to 100 KB depending on how the system is
configured and other conditions.
The maximum size of a single display data file or event data file when there are no freehand
messages is 18 MB. If a file includes freehand messages, the size is in the range of 24 MB
to 50 MB.
The file size when there are freehand messages is a reference.
Size of Information Other Than the Sampled Data
Item
File format identification block
File information block
Event information block
Time zone information block
Alarm block
Message block
Control information block
Control summary block
Control alarm summary block
Batch information block
Display information block
Group information block
Channel information block
Time change information block
Measurement data information block
Measurement data scan information block
The number of recording channels is the total of all the channels that are recording.
Example 1: When recording data for 30 I/O channels, 10 math channels, 50 communication
channels, and 10 group channels. Here we assume that there are no messages, alarms,
loops, program patterns, control summaries, or control alarms.
48 + 112 + 304 + 48 + 104 + 72 + 136 + 104 + 104 + 2360 + 224 + (24 + 264 × 10) + (24 +
328 × 90) + 280 + 96 + (40 + 16 × 90)
= 37,680 bytes
Sampled Data Size
• Data Size of Display Data and Event Data
Channel
I/O channel
Math channel
Communication channel
Time data common to all channels is added for each sample.
Time data
Size (Bytes)
48
112
304
48
104 + 56 × the number of alarms (5000 max)
72 + 200 × the number of messages
136 + 72 × number of loops + 40 × number of
program patterns
104 + 64 × number of control summaries
104 + 64 × number of control alarm summaries
2360
224
24 + 264 × the number of groups
24 + 328 × the number of recording channels
280
96
40 + +16 × the number of recording channels
Display Data
12 bytes/channel
12 bytes/channel
12 bytes/channel
16 bytes/sample
Event Data
6 bytes/channel
6 bytes/channel
6 bytes/channel
App-1
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App
Index