Mitsubishi Electric Q06CCPU-V, User Manual

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6
PREPARATORY PROCEDURES AND SETTING
6.9 Checking the Number of Erasures on the Standard ROM
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6.9 Checking the Number of Erasures on the Standard ROM
The standard ROM built in the C Controller module is used to save various parameters
and user programs.
Since a flash ROM is used as the standard ROM, the number of writes (life) is limited.
The life of the standard ROM must be taken into account when data are regularly written to
it.
This section describes the standard ROM life and how to check writing frequency.
(1) Standard ROM life
Data can be written to the same area of the standard ROM to the limit of 100,000
times.
The following shows the standard ROM life (reference value) in the case where files
are copied (written) every day.
* 1 When the file size is 512 bytes or less, plug 512 into the formula.
(2) Checking writing frequency to the standard ROM
Writing frequency to the standard ROM can be checked by obtaining the maximum
number of erasures of the standard ROM from the user program by using a function.
Include the following function in the user program so that the standard ROM life can
be estimated.
• Obtain the number of erasures by using plInfo[7] of the QBF_ReadStatusEx
function.
If the returned value exceeds 100,000, writing to the standard ROM may become
slower or result in an error.
Also, if this occurs, the event is registered to the event history.
Replace the C Controller module when the number of erasures has reached to
100,000 times.
POINT
Do not write data to any file in the standard ROM from a user program.
To write data to a file from a user program, use a file on the CompactFlash card.
Standard ROM life (days) = 600000/total size of files copied per day (MB)
*1
Q12DCCPU-V Q06CCPU-V Q06CCPU-V-B