ITMC PLC Operations 2

Question 1

Which PLC addressing mode directly specifies a memory location by its physical address without any calculation?

Accepted Answer

Direct addressing

Answer

Direct addressing specifies the exact memory location (e.g., I0.0, Q0.1) without any pointer calculation.

Question 2

In a PLC program, a TON timer's accumulated value (ACC) resets to zero when:

Accepted Answer

The enable (EN) bit turns OFF

Answer

A TON timer's ACC resets to zero whenever the rung condition (enable input) goes FALSE.

Question 3

What does the term 'scan time' refer to in PLC operation?

Accepted Answer

Time required to complete one full execution cycle of the ladder logic

Answer

Scan time is the total time for the PLC to read inputs, execute the program, and update outputs in one cycle.

Question 4

A CTU (Count Up) counter's output bit (CU) activates when:

Accepted Answer

The accumulated value equals the preset value

Answer

The CTU done bit turns ON when the accumulated count reaches or exceeds the preset value.

Question 5

Which communication protocol is most commonly used for high-speed deterministic communication between PLCs and I/O modules on a local network?

Accepted Answer

EtherNet/IP or PROFINET

Answer

EtherNet/IP and PROFINET are industrial Ethernet protocols designed for deterministic, high-speed PLC-to-I/O communication.

(ITMC) Industrial Technology Maintenance Certification Practice Test