B2-31
IM 34M06H62-02E 2nd Edition : June 2008-00
B2.4 How to Back up SP Values to EEPROM
The SP backup function is provided for writing SP values to the EEPROM so that these
parameter values are retained even after power off and on. In situations where you want
to predefine SP values so that they are valid right after power on, back up the values to
the EEPROM using the procedure given below. The SP backup function, when executed,
writes all SP values of all loops (1.SP.1 to 4.SP.4) to the EEPROM. Unless you perform
this procedure, SP values are not stored, and revert to their last stored values after power
off and on. However, beware that SP backup will not be executed if the parameter
backup function is disabled using the NBKUP parameter.
TIP
Updated SP values take effect immediately regardless of whether they are backed up to EEPROM.
There is no need to execute the SP backup function if SP values need not be retained.
Table B2.29 I/O Parameters Related to SP Backup
Data Position Number
Symbol Description Unit Data Range
Default
Value
Attribute Stored
Loop 1 Loop 2 Loop 3 Loop 4
74 SPWR Write set point to EEPROM None
0: No write
“WR”: Write
0 RW —
75 NBKUP Disable backup function None
0: Backup
1: No backup
0 RW —
77 and 78 (long word) EEP.CNTR EEPROM write counter Times 1 to 100,000 — RO —
201 401 601 801 1.SP Set point Industrial PRL to PRH PRL RW Irregular
221 421 621 821 2.SP Set point Industrial PRL to PRH PRL RW Irregular
241 441 641 841 3.SP Set point Industrial PRL to PRH PRL RW Irregular
261 461 661 861 4.SP Set point Industrial PRL to PRH PRL RW Irregular
Table B2.30 Input Relays Related to SP Backup
Input Relay Number Xnn
*1
Symbol Description Data Range Interrupt
Loop 1 Loop 2 Loop 3 Loop 4
32 SPWR.R Write SP to EEPROM Completed
0: Write in progress or not started;
1: Write completed
*1: denotes the slot number where the module is installed.
CAUTION
The SP backup function cannot be executed as long as the module is put into Setup
mode for the purpose of enabling controller and I/O parameter settings. After ensuring
that controller and I/O parameter settings are enabled, set up the required SP
parameters and then perform SP backup.
The SP backup function is available only with the F3CU04-1S and F3CU04-0S modules
of firmware revision 6 or higher. It is not available with F3CU04-1N or F3CU04-0N. You
can determine the revision of a module’s firmware from the REV value indicated on the
nameplate located on the side of the module, or from the value of the REV register (data
position number 90). As an example, “REV 06:05” on the nameplate denotes firmware
revision 6 and hardware revision 5.
CAUTION
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