Hakko Electronics Monitouch V Series, Справочное руководство

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Chapter 23 CF Card (V7 Only)
23-19
23
Sav
ing S
a
m
p
ling
Data
(
D
ata
Logg
in
g)
Cache
♦
Cache Function
There is a limit on the number of times you can write to a CF card because of the
limitations of the flash memory that is used. This limit effects the individual
sectors (512 bytes) rather than the entire card. When a CF card has reached
this limit, you cannot access a file (or a portion of the file) that includes the bad
sector. Note that if you often overwrite a CF card when sampling, you will
shorten the usable lifetime of the card and you may not be able to access some
files.
When selecting [CF Card Setting] from the [System Setting] menu and checking
[
Use Cache], cache memory is prepared for each buffer number. Because
sampling data is temporarily saved in this buffer memory until the conditions of
the outputing to a CF card are established (refer to “Conditions of Output to a CF
Card” mentioned later), it is possible to reduce the number of times you write to
the CF card.
♦
Adjustment of Cache Size
The sampling buffer size is determined by [Sampling Method], [No. of Words],
and [No. of Samples] in the [Buffering Area Setting] dialog. (Refer to “Chapter
10 Sampling.”) The interval time to output to a CF card is determined by
[Sampling Time] and [No. of Samples]. Taking these into consideration, you
need to adjust the cache size and reduce the number of writing. You can specify
the cache size in the range of 256 to 2048 words.
Supplemental Information
Lifetime of CF Card About 300,000 write operations
•
Write operations: every 5 minutes, when operating for 24 full hours:
About 3 years
•
Write operations: every 3 minutes, when operating for 24 full hours:
About 1.8 years
If you turn off the power or remove a CF card, the data is lost because cache
is volatile memory. Be sure to execute the [SMPL_SAVE] macro command to
save cache memory data before turning off the power or removing a CF card.