PLC Part 2

What is the function of System Read-Only-Memory (ROM) in a PLC system?

• To provide permanent storage for the operating system and fixed data used by the CPU

• To store user programs

• To maintain RAM contents in case of power loss

• To store input and output data

What type of memory is used for the user's program in a PLC system?

• System Read-Only-Memory (ROM)

• Random-Access Memory (RAM)

• Erasable and Programmable Read-Only-Memory (EPROM)

• Temporary buffer store

The term PLC stands for

• Personal logic computer

• Programmable local computer.

• Programmable logic controller.

• Personal logic controller.

Decide whether each of these statements is True (T) or False (F). A transistor output channel from a PLC: (i) Is used for only d.c. switching. (ii) Is isolated from the output load by an optocoupler. Which option BEST describes the two statements?

• (i) F (ii) F

• (i) T (ii) F

• (i) F (ii) T

• (i) T (ii) T

A transistor output channel from a PLC: (i) Is used for only d.c. switching. (ii) Is isolated from the output load by an optocoupler. Which option BEST describes the two statements?

• (i) F (ii) T

• (i) T (ii) F

• (i) T (ii) T

• (i) F (ii) F

The term sensor is used for an input device that .......................a usable output in response to a specified physical input

• Provide

• Provides

• Providing

• to provide

The term transducer ..............generally ............for a device that converts a signal from one form to a different physical form

• are/used

• is/using

• is/used

• are/using

This chapter provides a brief consideration of typical .....................and ....................... devices used with PLCs.

• Electrical, mechanical

• Mechanical, digital

• Programming, control

• Input, output

The term ........................... is used for an input device that provides a usable output in response to a specified physical input.

• Sensor

• Actuator

• Encoder

• Motor

What must be done to analogue signals before inputting them to PLC ports?

• Amplify

• Convert to digital

• Filter

• Transmit wirelessly