User`s manual

4-3

IM 05D01D12-41E 6th Edition: Mar. 25, 2005-00

■ If a Power Failure Occurs during Operation

● Momentary Power Failures shorter than 20 ms

The controller is not affected at all and continues normal operation.

● Power Failures of 20 ms or longer

• The alarm function of the controller continues to work normally. (Alarms with the

stand-by feature temporarily return to their stand-by state, however.)

• Setting parameters that have already been configured retain their settings.

• Auto-tuning is cancelled.

• After recovery from a power failure, control action resumes in the same mode as the

one before the occurrence of the power failure. The control output begins with the

preset output value.