Which of the following statements about a single pole double throw relay is NOT true?Ĩ. Which of the following statements about a single pole double throw relay is true?Ī) Insulators are used in the armature to isolate the electrical switching contacts from the rest of the relay components.ī) The NC contact and the pole are in contact when the relay is off.ĩ. Which of the following statements is NOT correct?Ī) If a problem in a PLC module occurs, the module can be changed in a matter of minutes without any changes in wiring.ī) Outputs can be paralleled on the same rung.Ĭ) The physical wires between the input and output field devices and the PLC input and output modules are the only signal wires required in the PLC system.ĭ) The cost and size of PLCs have increased significantly in the last 10 years.ħ.
#THE LADDER LOGIC PROGRAM IS USUALLY STORED IN SOFTWARE#
Which of the following statements is not correct?Ī) The PLC rung output is a discrete output instruction or bit in memory.ī) Each rung of the ladder logic represents a logical statement executed in software – inputs on the right and outputs on the left.Ĭ) Input and output instructions in ladder logic do not directly represent the switches and actuators.ĭ) PLC input instructions are logical symbols associated with voltage at the input module terminals.Ĥ. Which of the following statements is correct?Ī) Ladder logic is a PLC graphical programming technique introduced in the last 10 years.ī) A ladder logic program is hard to analyze because it is totally different when compared with the equivalent relay logic solution.Ĭ) The number of ladder logic virtual relays and input and output instructions is limited only by memory size.ĭ) The number of contacts for a mechanical relay is limited to number of coils on the relay.ĥ. Which of the following statements is NOT correct?Ī) The status of each input can be checked from one location and outputs can be forced on and off.ī) All symbols in the RLL represent actual components and contacts present in the control system.Ĭ) PLCs are not as reliable as electromechanical relays in RLL.ĭ) Input (-| |-) and output (- ( ) -) instruction symbols in the ladder logic represent only data values stored in PLC memory.Ħ.
0 kommentar(er)
