Yokogawa Removable Chassis DX1000N - Manual (Page 319)

App-1
IM 04L41B01-01E
Appendix
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Index
Appendix 1 File Size of Display Data and Event Data
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.
These calculation examples only apply to DXs that do not have the /AS1 advanced
security option.
File Size
A file consists of the following data.
Information other than the sampled data + the sampled data
The maximum size of a single display data file or event data file is 8 MB.
Size of Information Other Than the Sampled Data
Item Size [Bytes]
File header 216
Channel information 88×N + 32
Group information 96×10 + 32 = 992
Message information 104*50 + 32 (an add message area is reserved by default)
Batch information 832
Sampled data header 80 + 32 + N×8 + 16 + 2
Alarm information header 24 + 8 (add the size of this item even if there is no alarm)
Message information Up to 104×1050 (varies depending on the number of messages)
Alarm information Up to 32×5000 (varies depending on the number of alarms)
Release number 3 expansion
information
1696 + 80×N
Expansion information is always stored.
N is the number of channels (measurement channels + computation channels).
Example 1: If display data of 12 measurement channels and 24 computation
channels is recorded. There are no messages or alarms.
216 + (88 Ч 36 + 32) + 992 + (104 Ч 50 + 32) + 832 + (80 + 32 + 36 Ч 8 + 16 + 2) + (24
+ 8) + 4,576
= 15,498 bytes
Sampled Data Size
• Data Size of Display Data and Event Data
Channel Display Data Event Data
Measurement channel 4 bytes/channel 2 bytes/channel
Computation channel 8 bytes/channel 4 bytes/channel
Time data common to all channels is added for each sample.
Time data 8 bytes/sample
• Data Size per Sample
Display Data
(Number of measurement channels×4 bytes) + (number of computation channels×8
bytes) + 8 bytes (time data)
Event Data
(Number of measurement channels×2 bytes) + (number of computation channels×4
bytes) + 8 bytes (time data)
Appendix