YOKOGAWA FA-M3 VITESSE F3CX04-0N, Руководство пользователя

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B2-3
IM 34M06H63-01E 2nd Edition : Jul.16,2015-00

Common Precautions for Registers
Only registers listed in Table B2.3 and subsequent tables are valid data registers provided
with this module. Any number missing from the “Data Position Number” column in these
tables is omitted intentionally. When a value written to a valid data register exceeds the
valid data range, as indicated in the “Data Range” column in these tables, the written
value is ignored and the original value is restored. An out-of-range value written to a
monitoring parameter or input parameter, however, remains and is returned as read data
until an instruction is executed to enable the parameter, at which time, the out-of-range
value will be restored to the original value. At the same time, an error status is returned.
Any data written to a read-only (R/O) data register is ignored, in so far as it has no effect
on module operation. However, if the register is read immediately after the write operation
(for example, within the same scan of the sequence program), the written value may be
returned.
Any data written to an undefined register or a register that is considered invalid for a
module type or monitoring mode is ignored, in so far as it has no effect on module
operation. If the register is read after the write operation, however, the written value or a
register-specific value may be returned. The register-specific value may or may not be a
fixed value.
The “Attribute” column in a table indicates whether a register can be read and written.
“RO” indicates a read-only register, whilst “RW” indicates a register that can be read, as
well as written.
A “
 ” mark in the “Stored” column indicates that the content of the register is stored, and
need not be re-written to the module after powering off and on. When changing the value
of a stored register, beware, however, that there is a maximum limit to the number of write
operations allowed on the EEPROM. By default, writing to a stored register updates the
data stored in the EEPROM. To suspend this updating of the EEPROM, you should
disable the backup function.
Approx. 1 million (at 25

C or lower) or 100,000 (within temperature range) write
operations to the EEPROM are allowed. Beware that this write limit may be exceeded if
registers with a “  ” mark in the “Stored” column are frequently updated. In such situations,
you should disable the backup function by setting “NBKUP=1”. Note, however, that the
NBKUP register value itself is not stored, and is always reset to 0 at powering up.
CAUTION
CAUTION
CAUTION