PLC Exam 2
The field device that will cause the counter to increment is: See Figure 9
- output PL1
- input PB1
- output PL2
- input PB2 - Answer-input PB1
For the counter table shown, word-level addressing is used for: See Figure 10
- CU, CD, and DN
- PRE and ACC
- CU, CD, DN, PRE, and ACC
- CU, CD, DN, OV, UN, and UA - Answer-PRE and ACC
Which instruction will cause the counter to decrement? See Figure 11
- Enter switch input
- Lot Full Light output
- Exit switch input
- Reset input - Answer-Exit switch input
The 24-hour clock program shown uses: See Figure 12
- 2 timers and 1 counter
- 3 timers and 3 counters
,- 2 timers and 2 counters
- 1 timer and 2 counters - Answer-1 timer and 2 counters
The output Lot Full Light will be energized when the accumulated count is: See Figure 13
- 150
- 100
- 300
- 0 - Answer-150
The accumulated count of a CTD counter:
- decrements with each true-to-false transition
- increments with each false-to-true transition
- decrements with each false-to-true transition
- increments with each true-to-false transition - Answer-decrements with each false-to-true transition
A PLC up-counter (CTU) counts:
- a) scan transitions
- b) true-to-false transitions
- c) false-to-true transitions
- d) both b and c - Answer-false-to-true transitions
The PLC counter instruction is similar to the:
- transitional contact instruction
- internal relay instruction
- relay coil and contact instruction
,- timer instruction - Answer-timer instruction
When input PB2 is actuated: See Figure 14
- output PL is switched off
- counter C5:0 is reset
- counter C5:1 is reset
- all of these - Answer-all of these
A PLC down-counter (CTD) counts:
- a) scan transitions
- b) true-to-false transitions
- c) false-to-true transitions
- d) both b and c - Answer-false-to-true transitions
Programmed counters can:
- count up
- count down
- be combined to count up and down
- all of these - Answer-all of these
For the 24-hour clock program, RTO is preset for a: See Figure 15
- 24-h timer period
- 12-h time period
- 2-min time period
- 60-second time period - Answer-60-second time period
, The counter RES instruction:
- a) is used to reset the counter
- b) is given the same reference address as the counter instruction
- c) decrements the count when actuated
- d) both a and b
- e) both a and c - Answer-both a and b
Output PL will energize when: See Figure 16
- the accumulated value of C5:0 or C5:1 reaches 32,000
- the accumulated value of C5:0 reaches 32,000
- counter C5:0 is reset
- the accumulated value of C5:1 reaches 32,000 - Answer-the accumulated value of C5:1 reaches 32,000
The field device that will cause the counter to reset is: See Figure 17
- input PB2
- output PL1
- output PL2
- input PB1 - Answer-input PB2
For the 24-hour clock program, a false-to-true transition of rung 002 increments the clock by: See Figure
18
-1h
- 1 min
-1s
- 1 ms - Answer-1 h
The field device that will cause the counter to increment is: See Figure 9
- output PL1
- input PB1
- output PL2
- input PB2 - Answer-input PB1
For the counter table shown, word-level addressing is used for: See Figure 10
- CU, CD, and DN
- PRE and ACC
- CU, CD, DN, PRE, and ACC
- CU, CD, DN, OV, UN, and UA - Answer-PRE and ACC
Which instruction will cause the counter to decrement? See Figure 11
- Enter switch input
- Lot Full Light output
- Exit switch input
- Reset input - Answer-Exit switch input
The 24-hour clock program shown uses: See Figure 12
- 2 timers and 1 counter
- 3 timers and 3 counters
,- 2 timers and 2 counters
- 1 timer and 2 counters - Answer-1 timer and 2 counters
The output Lot Full Light will be energized when the accumulated count is: See Figure 13
- 150
- 100
- 300
- 0 - Answer-150
The accumulated count of a CTD counter:
- decrements with each true-to-false transition
- increments with each false-to-true transition
- decrements with each false-to-true transition
- increments with each true-to-false transition - Answer-decrements with each false-to-true transition
A PLC up-counter (CTU) counts:
- a) scan transitions
- b) true-to-false transitions
- c) false-to-true transitions
- d) both b and c - Answer-false-to-true transitions
The PLC counter instruction is similar to the:
- transitional contact instruction
- internal relay instruction
- relay coil and contact instruction
,- timer instruction - Answer-timer instruction
When input PB2 is actuated: See Figure 14
- output PL is switched off
- counter C5:0 is reset
- counter C5:1 is reset
- all of these - Answer-all of these
A PLC down-counter (CTD) counts:
- a) scan transitions
- b) true-to-false transitions
- c) false-to-true transitions
- d) both b and c - Answer-false-to-true transitions
Programmed counters can:
- count up
- count down
- be combined to count up and down
- all of these - Answer-all of these
For the 24-hour clock program, RTO is preset for a: See Figure 15
- 24-h timer period
- 12-h time period
- 2-min time period
- 60-second time period - Answer-60-second time period
, The counter RES instruction:
- a) is used to reset the counter
- b) is given the same reference address as the counter instruction
- c) decrements the count when actuated
- d) both a and b
- e) both a and c - Answer-both a and b
Output PL will energize when: See Figure 16
- the accumulated value of C5:0 or C5:1 reaches 32,000
- the accumulated value of C5:0 reaches 32,000
- counter C5:0 is reset
- the accumulated value of C5:1 reaches 32,000 - Answer-the accumulated value of C5:1 reaches 32,000
The field device that will cause the counter to reset is: See Figure 17
- input PB2
- output PL1
- output PL2
- input PB1 - Answer-input PB2
For the 24-hour clock program, a false-to-true transition of rung 002 increments the clock by: See Figure
18
-1h
- 1 min
-1s
- 1 ms - Answer-1 h
