Author Question: Automatic control is a system where a process variable is forced to remain at a desired value called ... (Read 117 times)

captainjonesify · **on:** Jul 28, 2018

Automatic control is a system where a process variable is forced to remain at a desired value called the controller output point.

Indicate whether the statement is true or false

Question 2

Which of the following statements is NOT true during a PLC scan?

A) The PLC uses the value in the input register to set the conditions for input logic symbols.
B) Input values are scanned first.
C) If the output symbol is active it turns on the output field device and then sets the corresponding bit in the output register to a one.
D) The voltage present at the input terminals determines the value of the input register.
E) If power flow is present in a contact, the contact is highlighted.