YOKOGAWA FA-M3 VITESSE F3CX04-0N, User Manual

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A2-7
IM 34M06H63-01E 2nd Edition:Jul.16,2015-00
A2.5 Backup Function
The F3CX04-0N temperature monitoring module stores input type, input range and many
other parameters internally each time the corresponding registers are updated, unless the
backup function is disabled.
Take note, however, that there is a maximum limit to the number of write operations
allowed for the backup function.
Table A2.5 Backup Function
Description
Stored parameters
Monitoring parameters, input parameters, and operation parameters. For details,
refer to the register list.
Number of write
operations
Approx. 1 million (at 25

C or lower) or 100,000 (within temperature range) write
operations allowed.
Disable backup function
This parameter disables the backup function. It may be used, if required, to avoid
reaching the maximum limit for write operations.
CAUTION
For details on the I/O data registers that are stored by the backup function and their data
position numbers, see Section B2, "Types of Relays and Registers."
CAUTION
In situations where the CPU module frequently overwrites the I/O data registers
earmarked to be stored by the backup function, the maximum limit for write operations
may be reached. To prevent this, turn on the Disable Backup Function parameter. Once
the write limit is reached, data backup is no longer allowed and the system enters
hardware failure mode. Furthermore, parameter data may be reset at system startup to
the default values given in Section B2, "Types of Relays and Registers."