PLC 1A Flashcards
(21 cards)
If a diffused photo-eye input switches to the negative when it detects an object, then the device is:
sinking and the input module must be sourcing
A PLC has a given memory unit consisting of 1250 “words”.
The memory capacity would be rated:
20,000 bits
Optocouplers are best described as:
Light Signal transmitters between the Modules and the CPU
Which of the following is NOT generally built in to each PLC input and output?
Fuses
In a PLC system, there is an electrical connection between the field I/O devices and the CPU.
False
A discrete output interface module is designed to provide:
Simple ON/OFF switching control
The __________ is a developmental tool that helps the user by displaying the state of the controller’s inputs and outputs at any time in the sequence or application
Truth table
_______________ provide a graphic representation of the control wiring between a controller’s output terminals and the output device to which it is connected
I/O diagrams
The layout of the diagram shown here is that of a (an):
L1——————-L2
with switches and PB that go to L1,1,2,3,4,L2
Attempt #32 Q#6
input module wiring diagram
Which statement does not apply to the optical isolator circuit used in I/O modules?
They rectify AC signals
Test Mode:
Same as Run Mode only Inputs operate
Two machines are __________ when they are interfaced through an isolating device such as a relay contact.
indirectly connected
If a photo-eye input switches the negative when it detects an object then:
the device is sinking and the input module must be sourcing
Seen here is a simplified discrete input module.
The purpose of R1 & R2 is to:
Lower the applied voltage
A starter with a coil rated at 480v must pick up as a result of a 240 v rated relay type PLC output going on. What is required?
An electromechanical relay with a 240 v coil and 480 v rated contacts
The PLC will perform the following during RUN MODE:
Scan the program, Update Inputs and then activate Ouputs
When the controller is first placed in the “run” mode, the status of all process contacts connected to the input module interface:
is recorded in memory
In PLC operating modes, the test mode will:
Run the program without activating real outputs
Initial Set up and/or Configuration of the hardware devices requires:
Model Numbers of the Input and the Output Modules
A discrete output interface module is designed to provide:
Simple ON/OFF switching control
I am designed to permanently store a program that cannot be altered under any circumstances. Who am I?
ROM
