MC II: Lesson 7 - Electronic Programmable Timers

Question 1

______ timers have a coil and the timing function is initiated when the coil is energized or de-energized.

a. Electromechanical
b. Solid-state

Answer 1

a. Electromechanical

Question 2

Standard NO and NC symbols on a control diagram represent what type of contact function?

a. Instantaneous
b. Off-delay
c. On-delay

Answer 2

a. Instantaneous

Question 3

______ devices need constant power to operate. The timing functions are initiated by the presence or absence of a separate “trigger” signal.

a. Electromechanical
b. Solid-state

Answer 3

b. Solid-state

Question 4

NOTC and NCTO symbols on a control diagram represent what type of contact function?

a. Instantaneous
b. Off-delay
c. On-delay

Answer 4

c. On-delay

Question 5

The solid-state ______ timer requires constant power to operate the electronics. When a signal is received from the trigger circuit, the timing period is initiated. When the timing period has elapsed, the “contacts” change state. The contacts will remain in the activated state the entire time the trigger signal is present. The contacts will return to their normal state as soon as the trigger signal is removed.

a. off-delay
b. on-delay

Answer 5

b. on-delay

Question 6

A solid-state ______ timer requires constant power to operate electronics. When a signal is received from the trigger circuit, the “contacts” will instantly change state. They will remain in this state the entire time the trigger signal is present. When the trigger signal is removed, the timing period is initiated. When the timing period has elapsed, then the contacts will return to their normal state.

a. off-delay
b. on-delay

Answer 6

a. off-delay

Question 7

The ______ solid-state timer is a timing device in which the “contacts” will instantly change state when the timer is powered on or an external trigger is applied. The contacts will remain in the activated state until the timing period has elapsed.

a. off-delay
b. one-shot
c. repeat-cycle

Answer 7

b. one-shot

Question 8

The ______ timer is a timing device in which the contacts cycle open and close repeatedly once the timer is activated.

a. off-delay
b. one-shot
c. repeat-cycle

Answer 8

c. repeat-cycle

Question 9

______ recycle timers allow independent control of the ON period and OFF period.

a. Asymmetrical
b. Symmetrical

Answer 9

a. Asymmetrical

Question 10

A ______ programmed timing function does not retain its accumulated value between input signals.

a. non-retentive
b. retentive

Answer 10

a. non-retentive

Question 11

A ______ programmed timing function retains its accumulated value between input signals.

a. non-retentive
b. retentive

Answer 11

b. retentive

Question 12

The ______ value is the number of time units a programmed timer is programmed to count before timed contacts change state.

a. accumulated
b. preset
c. time base

Answer 12

b. preset

Question 13

The ______ value is the current number of time units a programmed timer has counted after the timing period has been initiated.

a. accumulated
b. preset
c. time base

Answer 13

a. accumulated

Question 14

Programmable logic relay timing functions provide an adjustable ______ that allows precise timing with accuracy within a hundredth of a second.

a. accumulated
b. preset
c. time base

Answer 14

c. time base

Question 15

Programmed timers’ output contacts change state when the ______ value equals the preset value.

a. accumulated
b. preset
c. time base

Answer 15

a. accumulated

Question 16

Typical time bases available for programmable timers are 0.01, 0.1, and 1.0 minutes.

True or False

Answer 16

False

Question 17

The actual amount of time a programmable timer measures is the ______ value times the time base.

a. accumulated
b. preset
c. time base

Answer 17

b. preset

Question 18

Programmable ______ timers can emulate a seven-day time clock.

a. accumulated
b. non-retentive
c. real time clock

Answer 18

c. real time clock

Question 19

Programmable timers can be programmed with the front panel keypad and LCD display, but the recommended approach is to use a PC and the software supplied by the manufacturer.

True or False

Answer 19

True

Question 20

Programmable timers can perform as multiple separate timers that can simultaneously perform different timing functions.

True or False

Answer 20

True

Question 21

A computer and the manufacturer’s programming software can be a tremendous aid when troubleshooting programmable timers.

True or False

Answer 21

True

Question 22

One important first step in troubleshooting programmable devices is to determine if it is a hardware problem or a software problem.

True or False

Answer 22

True

Question 23

Use the ladder diagram and description as a reference. What is the timer mode for the second timer?

a. 1
b. 4
c. 10

Answer 23

a. 1

Question 24

Use the ladder diagram and description as a reference. What is the preset value for the second timer?

a. 1 minute
b. 5 minutes
c. 10 minutes

Answer 24

c. 10 minutes

Question 25

Use the ladder diagram and description as a reference. What is the timer unit for the second timer?

a. 0.00-99.99 sec
b. 0.0-999.9 sec
c. 0-9999 sec
d. 0-9999 min

Answer 25

d. 0-9999 min

Question 26

Use the ladder diagram and description as a reference. What is the current timer value for the second timer?

a. 5 sec
b. 10 sec
c. 5 min
d. 10 min

Answer 26

c. 5 min