In the previous article, we built a complete digital I/O architecture.
Digital signals are relatively simple:
0 = OFF
1 = ON
Analog signals are different.
An analog input may represent:
Tank level
Pressure
Temperature
Flow
Speed
Weight
pH
Conductivity
Valve position
Motor current
Instead of …
Read MoreIn PLC programming, not all logic is simple ON/OFF control.
Sometimes the PLC needs to work with numbers.
The PLC may need to:
Move a value from one tag to another
Compare a process …
In PLC programming, not all logic is simple ON/OFF control.
Sometimes the PLC needs to work with numbers.
The PLC may need to:
Move a value from one tag to another
Compare a process …
From Raw Counts to Engineering Units
In industrial automation, a PLC does not automatically understand pressure, level, flow, temperature, or weight.
The PLC receives an electrical signal from the field instrument. That …
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