App-1
IM MV1000-01E
Appendix
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App
Index
Appendix
Appendix 1 Data File Size
This section explains how to calculate the file sizes of display data files and event data
files. The calculation examples are for when the MV is set to record only display data or
only event data. 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 estimate.
File Size
A file consists of the following:
sampled-data related information + sampled data
The maximum size of a single display data file or event data file is 8 MB.
Sampled-Data Related Information Size
Item Size in Bytes
File header 216
Channel information 88×N + 32
Group information 96×10 + 32 = 992
96×36 + 32 = 3,488
(MV1000)
(MV2000)
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)
N is the number of channels (measurement channels + external input channels + computation
channels).
Example 1:
When recording measured data of 30 measurement channels, 240
external input channels, and 10 computation channels with no messages
or alarms.
216 + (88×280 + 32) + 3,488 + (104×50 + 32) + 832 + (80 + 32 + 280×8 + 16 + 2) + (24 + 8)
=
36,842 bytes
Sampled Data Size
• Data Sizes of Display Data and Event Data
Channel Display Data Event Data
Measurement channel 4 bytes/channel 2 bytes/channel
External input channel 4 bytes/channel 2 bytes/channel
Computation channel 8 bytes/channel 4 bytes/channel
Time data is added to all channels at each sampling.
Time data 8 bytes/sample
• Data Size per Sample
Display Data
(Number of measurement channels×4 bytes) + (number of external input channels×4
bytes) + (number of computation channels×8 bytes) + 8 bytes (time data)
Event Data
(Number of measurement channels×2 bytes) + (number of external input channels×2
bytes) + (number of computation channels×4 bytes) + 8 bytes (time data)