Internal relay instructions are used when:
A)real-world input field devices are needed as inputs.
B)real-world output field devices are needed as outputs.
C)other than real-world field devices are needed as input or output reference instructions.
D)both a and b.

Question

Quizplus · Accepted Answer

Internal relay instructions are used for operations within the PLC program that do not directly interact with real-world input and output devices. They serve as internal contacts and coils within the program logic, allowing for complex control strategies without the need for physical input or output devices.

Internal Relay Instructions Are Used When