TOPIC 1 - INTRODUCTION TO AUTOMATION SYSTEM

The timed relay contact shown is designed to operate so that:

• a. when the relay coil is energized, there is a time delay in closing

• b. when the relay coil is energized, there is a time delay in opening

• c. when the relay coil is de-energized, there is a time delay in closing

• d. when the relay coil is de-energized, there is a time delay in opening

The timing diagram shown is that of an

• a. on-delay timer circuit (NOTC contact)

• b. on-delay timer circuit (NCTO contact)

• c. off-delay timer circuit (NCTC contact)

• d. off-delay timer circuit (NOTO contact)

In the circuit shown, the light will stay off

• a. as long as S1 is closed

• b. for 10 seconds after coil TD is energized

• c. for 10 seconds after coil TD is de-energized

• d. both a and c

________is a PLC instruction measuring the amount of time elapsed following an event.

• Timer

• Latching

________ is used for circuit that is able to hold the output energized.

• Timer

• Latching

________ is a PLC instruction that counts the number of occurrences of an event.

• Timer

• Counter

In a timer circuit, the output will remain active:

• d. for a fixed duration regardless of the timer setting

• b. immediately after the timer is energized

• c. only when the timer is de-energized

• a. until the timer reaches its preset value

________ is a type of relay that maintains its state after the control signal is removed.

• Timer

• Latching relay