defination of plc? why we use plc? application of plc?
advantage of plc?
Answer Posted / eswar
PLC is a small computer used for automation of real world
process such as control of machinery on factory assembly
lines.where older automated systems would use hundreds or
thousands of relays,a single PLC can be programmed as a
replacement.
example maintaining of water level in a tank between two
float switches by opening or closing an electric valve.
In this example plc accepting two digital inputs from two
float switches.The plc controlling a single digital output
to actuate the inlet value valve into tank.
advantages:
1 flexibility:one single Plc can easily run many machines
2with plc we can do any changes in circuit design and we can
correct the errors.
3 pilot running
4 visible observation
5 space efficency: todays plc's have more memory therefore
we can generate more and more contacts timers,coils,counters.
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