Introduction
One of the best ways to improve PLC programming skills is to stop thinking only in terms of individual instructions and start thinking in terms of process behavior, equipment states, …
Read MoreIn 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 …
Is It the Sensor, Wiring, PLC Card, Scaling, or HMI?
Analog input troubleshooting is one of the most valuable skills for an automation technician.
When an HMI value looks wrong, unstable, frozen, …
Read MoreFrom 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 …
Read MoreA Practical Guide for Automation Technicians
One of the most important signals in industrial instrumentation is the 4–20 mA current loop.
If you work with pressure transmitters, level transmitters, flowmeters, temperature transmitters, …
Read MoreTurning Real-World Signals Into Useful Numbers
In PLC troubleshooting and programming, not every signal is simply ON or OFF.
Many devices send a variable signal that represents a real-world measurement, such as:
TemperaturePressureLevelFlowWeightValve …
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