Basic Programming Instructions

Question 1

What are three types of programming languages that are used for programming PLCs?

Answer 1

• Relay ladder logic
• Boolean mnemonics
• Function block
• Structured Text

Question 2

The term EXAMINE IF ON instruction refers to _______________

Answer 2

a normally open (NO) instruction

Question 3

The last instruction to be entered in a logic rung is a/an _____________

Answer 3

coil

Question 4

Latching relay is __________________

Answer 4

an output instruction

Question 5

Latching relay instruction ____________________

Answer 5

Maintains an energized or de-energized state after power failure

Question 6

EXAMINE IF ON instruction will be true when __________________

Answer 6

memory bit is a 1

Question 7

What is the difference between an internal relay instruction and an output instruction?

Answer 7

There is no terminal wiring corresponding to internal bit relating to internal relay

Question 8

For how many scans does the one-shot instruction remain true when enabled?

Answer 8

one

Question 9

Internal relays are:

a. accessible at the I/O rack
b. not accessible at the I/O rack
c. not practical in PLC circuits
d. also known as hardware coils

Answer 9

b. not accessible at the I/O rack

Question 10

The PLC timer is said to be enabled when _________________

Answer 10

The timer rung is made true

Question 11

For a timer address T5, what will be the address equivalent to instantaneous contact?

Answer 11

T5/EN

Question 12

If the time base of the timer is 0.1s, what should be the pre-set value for 5.1s?

Answer 12

51

Question 13

Under what condition will the counter accumulator register increment?

Answer 13

Whenever the count input goes from false to true transition