46
Power Failure Protection
A power sequence circuit is incorporated in the PC to prevent malfunctioning
due to momentary power failures or voltage drops.
The PC ignores all momentary power failures if the interruption lasts no
longer than 10 ms. If the interruption is between 10 ms and 25 ms, it may or
may not be detected. If the supply voltage drops below 85 for longer than 25
ms, the PC will stop operating and the external outputs will be automatically
turned off. Operation automatically resumes when the supply voltage is re-
stored to more than 85 of the rated voltage. Detection time will be slightly
shorter when a DC power supply is used.
Momentary power
failure detection
time
Power Supply
Power failure
detection signal
CPU voltage (5V)
Power reset
Run monitor
outputs
Approx. 1 s
2-8
Switch Settings
After writing the program and preparing the EPROM chip (see the
Operation
Manual
), the CPU DIP switch must be set and the EPROM installed.
2-8-1
Setting the CPU DIP Switch
1, 2, 3...
1.
Turn OFF the power to the CPU.
2.
Remove the cover from the CPU, using a screwdriver if necessary.
Switch Settings
Section 2-8
