PLC Exercises I – Learnchannel-TV.com

The output should only switch to state “1” if only one input has a logical “1” at a time. Which logical function do you have to use here?

NOR

XOR

XNOR

NAND

NOR

Which logical function is represented in this truth table?

XNOR

NOR

AND

XOR

NAND

A fan should run (Q1 = 1) when the main switch is actuated (S = 1), the temperature sensor (bimetal) reports overtemperature (T = 0) and the motor is running (S2 = 1). Which logical function can be applied to this task?

PLC Ladder 2

Program 4

Program 1

Program 2

Program 5

Program 3

Which statement about the function of this PLC program is correct?

PLC – 2 from 3 circuit

The warning light is active if at least two of the three temperature sensors give high-signal.

The warning light only lights up if the temperature sensor B2 gives a high-signal.

The warning light only lights up if 2 temperature sensors give a high-signal.

The warning light only lights up when all three temperature sensors give a high-signal.

The warning light only lights up if all 3 temperature sensors give high-signal.

Which statement about the following logical function is correct?

Interlocking Outputs in PLC

I0 and I1 can never have a 1-signal at the same time.

Pump and valve cannot be switched on at the same time.

The valve opens when the pump is in operation.

The pump can be switched on when a High-signal is applied to I0.

The valve must be open when a High-signal is applied to I1.

Check Yourself!