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73VR2102 / 73VR2104 / 73VR2106 / 73VR2108 / 73VR2110 / 73VR2112 USERS MANUAL EM-7395-B Rev.24
10.2 DATA STORAGE TIME
Data storage time for one CF Card depends upon the following:
1. Storing rate
2. Data storing form
3. Number of channels
There are also CF Cards of different capacities.
Data storage time of a CF Card is calculated as follows:
Record Size
[Date Information] (bytes) + [One Sample Data] (bytes) x [No. of Channels] (points) = [Record Size] (bytes)
Number of Records
[CF Card Memory Size]
*
(bytes) / [Record Size] (bytes) = [Number of Records]
Data Storable Time
[Number of Records] x [Storing Rate] (seconds) = [Data Storage Time] (seconds)
Date information takes 8 bytes and one bit of sampled data takes 4 bytes with the floating point form, 2 bytes with
short integer form. No. of channels must include all channels set to ‘Enable.’
*
[CF Card Memory Size] means the volume of data file (73VR.VRD21) created in the CF Card.
[Example]
Storing rate: 5 sec.
Data storing form: Short integer
Number of channels: 6
CF Card memory size: 118 MB (for 128 MB CF Card)
A record size is calculated as:
8 (bytes) + 2 (bytes) x 6 (points) = 20 (bytes)
The number of records which can be stored in this CF card is calculated as:
(118 x 1024 x 1024
**
) (bytes) / 20 (bytes) = approx. 6186598 (records)
Time duration usable for the number of records is:
6186598 x 5 (sec.) = 30932990 (sec.) = approx. 8592 hours. = approx. 358 days
**
1KB-CF card’s memory size is calculated as 1024 bytes.
This calculated result is only for approximate estimation since the data file must be smaller than the full capacity of
a CF Card.
