Parameter-Valid Drive - Mitsubishi Electric L02SCPU User's Manual And Reference

2.1.2

Parameter-valid drive

CPU modules operate according to parameter settings. Systems automatically select parameters from those stored in
the drives for CPU module operation, according to the following priority order.
[Priority order]
1) Drive 0 (program memory)
2) Drive 2 (SD memory card)
3) Drive 4 (standard ROM)
● If parameters are set to be booted to an SD memory card, the above priority order is applied after the parameters are
booted to the specified destination. ( Page 74, Section 2.9)
● The parameters used by the CPU module can be checked at "Parameter Valid Drive Information" under "PLC Status
Information" on the "PLC Diagnostics" dialog box. ( Page 376, Appendix 2)
[Diagnostics]  [PLC Diagnostics]
(1) Timing that the parameters take effect
The CPU module automatically searches for parameters in the following timing and operates according to the
parameters stored in the drive.
• When the CPU module is powered off and then on
• When the CPU module is reset
(2) Precautions
Note that if the parameters are written while the CPU module is in operation, the timing that the parameters take
effect varies.
(a) To write a parameter to the drive other than the one in operation:
The CPU module keeps operating according to the current parameters. When the CPU module is turned off
and then on or is reset, newly written parameters take effect according to the priority order.
(b) To write a parameter to the drive where another parameter is currently processed:
Only the device settings become effective immediately after writing is complete. To make all the parameters
effective, power off and then on or reset the CPU module.
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