(ACTUAL2024-2025) QUESTION AND ANSWERS.
Sequencers - <<Answers>>>A sequencer is a highly
convenient feature for programming machines or processes
which operate in fixed sequences. These machines operate in
fixed, clearly distinguishable step-by-step order, starting from
an initial step and progressing to the final step and then restart
from the initial step again. At any moment, there must be a
"step counter" to keep track of the current step number. Every
step of the sequence must be accessible and can be used to
trigger some action, such as turning on a motor or solenoid
valve, etc.
Mask - <<Answers>>>Think of the bit mask as a gate, where
if it's a 1 then information is let through, but if its a 0 then no
information is let through.
HMI (human-machine interface) - <<Answers>>>HMIs may
take the form of general-purpose ("personal") computers
running special graphic software to interface with a PLC, or
as special-purpose computers designed to be mounted in sheet
metal panel fronts to perform no task but the operator-PLC
interface.
ASCII - <<Answers>>>American Standard Code for
Information Interchange. A code used to represent common
numbers, letters, special symbols and control codes.
, PROGRAMMABLE LOGIC CONTROLLERS TEST
(ACTUAL2024-2025) QUESTION AND ANSWERS.
Back Plane - <<Answers>>>The printed circuit board at the
back of the PLC rack where the modules connect to a power
supply and data bus.
Control system breakdown - <<Answers>>>Every control
system may be divided into three general sections: input
devices (sensors), controllers,
and output devices (actuators).
PLCs - <<Answers>>>A programmable logic controller or
PLC is a general-purpose controller, applicable to many
different types of process control applications.
Programmable - <<Answers>>>The end-user is able to
program, or instruct, the PLC to do virtually any control
function imaginable.
Ladder Diagram - <<Answers>>>Ladder Diagram PLC
programs resemble ladder-style electrical schematics, where
vertical power "rails" convey
control power to a set of parallel "rung" circuits containing
switch contacts and relay coils.
Input devices - <<Answers>>>Typical devices connecting to
a PLC's inputs include hand switches, process switches,
sensors,