Controls
The core disciplines of an industrial control system: the logic solver, the operator interface, the field devices that measure the process, and the panel that ties them together.
Written guides in this section
Full references, procedures, and diagnostic guides published under Controls.
4-20 mA Current Loops
Why the industry standardized on current instead of voltage, how a two-wire loop is powered, what the live zero buys you, and how to read a loop with a meter.
12 min readUpdated Aug 29, 2026
UL 508A Industrial Control Panels
What the listing actually covers, what has to appear on the label, and the requirements that most often cause a panel to fail inspection.
9 min readUpdated Aug 25, 2026
What Is a PLC?
A programmable logic controller is a ruggedized industrial computer that reads field inputs, solves a control program, and drives outputs on a repeating, deterministic cycle.
8 min readUpdated Aug 22, 2026
PID Control for Pumps and Valves
What each term actually does, how to tune a loop on a real pump station, and the handful of mistakes that cause most of the oscillation people blame on tuning.
11 min readUpdated Aug 19, 2026
Lead/Lag Pump Control
Which pump runs first, when the second joins, how they trade places, and the design decisions that determine whether a duplex station wears evenly.
9 min readUpdated Aug 18, 2026
ISA-18.2 Alarm Management
The lifecycle standard for alarm systems, the rate targets that define a workable system, and why alarm rationalization is the step nobody wants to fund.
10 min readUpdated Aug 15, 2026
Browse Controls
PLC Systems
Architecture, programming, analog control, communications, and troubleshooting for programmable logic controllers.
63 topics
SCADA & HMI
Supervisory control, operator interface design, alarm management, and historian data.
52 topics
Instrumentation
Flow, level, pressure, and analytical measurement — selection, installation, signals, and calibration.
44 topics
Control Panels
UL 508A design, pump and PLC panels, component selection, and panel troubleshooting.
42 topics
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