Chapter 4. CPU module
4 - 3
2) Time driven interrupt operation method
In time driven interrupt operation method, operations are processed not repeatedly but at every pre-set interval.
Interval, in the GM6 CPU module, can be set to between 0.01 to 4294967.29 sec. This operation is used to
process operation with a constant cycle.
3) Event driven interrupt operation method
If a situation occurs which is requested to be urgently processed during execution of a PLC program, this
operation method processes immediately the operation which corresponds to interrupt program. The signal
which informs the CPU module of those urgent conditions is called interrupt signal. The GM6 CPU module has
two kind of interrupt operation methods, which are internal and external interrupt signal methods.
4.2.2 Operation processing at momentary power failure occurrence
The CPU module detects any momentary power failure when the input line voltage to the power supply
module falls down below the defined value.
When the CPU module detects any momentary power failure, the following operations will be executed.
1) Momentary power failure within 20 ms
(1) The operation processing is stopped with the output retained.
(2) The operation processing is resumed when normal status is restored.
(3) The output voltage of the power supply module retains the defined value.
(4) The watch dog timer(WDT) keeps timing and interrupt timing normally
while the operations is at a stop.
2) Momentary power failure exceeding 20 ms
•
The re-start processing is executed as the power is applied.
REMARK
1) Momentary power failure
The PLC defining power failure is a state that the voltage of power has been lowered outside the allowable variation
range of it. The momentary power failure is a power failure of short interval(several to tens ms).
