How to Build a PLC Timer Loop Sequence
This is a full build-along tutorial that goes beyond the Bob Teaches Tech YouTube video. It covers the hardware, wiring, GX Works2…
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How to Build an Electro-Pneumatic Reciprocating System With a 5/2 Solenoid Valve
Learn how to build an electro-pneumatic reciprocating system using a 5/2 solenoid valve, double-acting cylinder, limit switches, relays, or a PLC.
SCADA vs HMI vs PLC
SCADA, HMI, and PLC get used almost interchangeably in job postings and casual shop-floor conversation, but they aren't competing technologies, they're three…
How to Wire a Photoelectric Sensor to an AC Timer Relay
Learn how to connect a 24V DC photoelectric sensor to an AC timer relay using an interposing relay. Complete wiring guide with…
Proximity Sensors Explained: Inductive vs Capacitive vs Photoelectric
Inductive, capacitive, and photoelectric sensors all answer the same basic question, is something there?, but they sense completely different physical properties, and…
What Is SCADA? Architecture, Components, and How It Works
SCADA lets a single operator monitor and control equipment spread across an entire plant, pipeline, or utility network — here's what the…
Arduino Digital I/O Explained: pinMode, digitalRead, digitalWrite
Arduino digital I/O explained: pinMode, digitalRead, and digitalWrite with a tested button-and-LED wiring and code example.
Structured Text Programming for PLCs: A Practical Introduction
Structured text (ST) is the IEC 61131-3 language that feels most familiar to anyone with a Pascal or C background - and…
Modbus Register Types Explained: Coils, Discrete Inputs, Holding Registers
Modbus register types explained: coils, discrete inputs, holding and input registers, function codes, and addressing conventions.
How to Set Up a Modbus TCP Connection Between a PLC and SCADA
Step-by-step guide to connecting a PLC to SCADA over Modbus TCP, including port 502 setup and a troubleshooting table.