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PLC and Automation Guides, Page 3

In-depth PLC programming and industrial-automation guides: ladder logic, timers, SCADA, HMI and communication, plus the practical know-how the field runs on.

Flat vector diagram of a tank fill control system showing level sensors, inlet valve, transfer pump, and connections to a PLC I/O rack for a ladder logic exercise
ladder logictank fill controlplc exercise

Tank Fill Control PLC Exercise: Ladder Logic

Build a tank fill control program from scratch. This exercise covers level sensor inputs, inlet valve control, pump sequencing, high-level fault latching, and HMI interlock in ladder logic.

Jul 25, 2026 · 7 min read

Flat vector diagram showing the ISO 13849-1 Performance Level scale from PLa to PLe with safety function icons and risk parameter arrows
functional safetyiso 13849-1performance level

ISO 13849-1 PL Levels: What They Mean in Practice

ISO 13849-1 Performance Levels (PLa to PLe) define how reliable a safety function must be. Learn how PL is determined, how it compares to SIL, and what it means for your machine design.

Jul 24, 2026 · 9 min read

Flat vector diagram comparing a small control relay and a 3-phase contactor side by side on a DIN rail, with coil terminals and auxiliary contacts labeled
relay vs contactorcontrol panel wiringelectrical fundamentals

Relay vs Contactor: Wiring Differences Explained

Relays and contactors both switch circuits, but they're built for different jobs. Learn the key wiring differences, coil ratings, auxiliary contacts, and when each device belongs in your panel.

Jul 24, 2026 · 9 min read

Flat vector diagram of an electrical transformer showing primary and secondary windings with turns ratio labels and connections to a PLC control panel terminal block
electrical fundamentalstransformer wiringcontrol panel

Electrical Transformer Basics: How They Work and How to Wire Them

Learn how electrical transformers work, how to calculate turns ratio and VA sizing, and how to wire a 24V control transformer step by step.

Jul 24, 2026 · 9 min read

Flat vector diagram of a VFD connected to a motor and PLC with labeled parameter setting groups including frequency limits, accel and decel, and control mode
vfd parametersvariable frequency drivedrives

VFD Parameters Explained: 12 Settings You Must Get Right

Learn which VFD parameters matter most, what values to set, and the common mistakes that cause nuisance trips, motor damage, and failed startups.

Jul 23, 2026 · 9 min read

Flat vector diagram of a SCADA remote access architecture showing a laptop connecting through a VPN tunnel and dual firewalls to a SCADA server and PLC rack in a segmented OT network
scadaremote accesscybersecurity

SCADA Remote Access: How to Do It Safely

Remote access to SCADA systems is unavoidable in modern plants, but done wrong it is a direct path to a breach. Here is how to set it up safely.

Jul 23, 2026 · 9 min read

Flat vector diagram of an HMI screen displaying a prioritised alarm list connected to a PLC rack and tag database, illustrating HMI alarm configuration workflow
hmi programmingalarm managementhmi configuration

HMI Alarm Configuration: From Raw Bit to Useful Alert

Learn how to configure HMI alarms correctly: priority levels, deadbands, acknowledgment workflows and the display rules that separate useful alerts from alarm floods.

Jul 23, 2026 · 9 min read

Flat vector diagram of an IO-Link master connecting four sensors to a PLC over PROFINET, showing process data flow on each sensor cable
io-linkindustrial protocolsplc sensors

IO-Link Explained: How It Works with Your PLC

IO-Link turns a standard sensor cable into a two-way digital channel. This guide explains how the protocol works, how masters connect to your PLC, and what you actually gain on the plant floor.

Jul 22, 2026 · 9 min read

Flat vector diagram of OPC UA protocol architecture connecting a PLC to SCADA, historian and cloud clients through a central OPC UA server block
opc uaindustrial protocolsscada

OPC UA Protocol Explained for PLC Engineers

OPC UA is the industrial protocol linking PLCs to SCADA, historians and cloud systems. Learn how nodes, sessions, security and subscriptions actually work in plain terms.

Jul 22, 2026 · 10 min read

Flat vector diagram of GX Works3 IDE on a laptop connected via USB to a Mitsubishi iQ-F PLC on a DIN rail, showing ladder logic rungs and device monitor callouts
mitsubishi plcgx works3iq-r series

GX Works3: A Practical Getting-Started Guide

GX Works3 is Mitsubishi's unified IDE for iQ-R and iQ-F PLCs. This guide walks you through setup, project creation, ladder programming, device monitoring, and writing to hardware.

Jul 22, 2026 · 8 min read

Flat vector diagram of an Omron NJ PLC rack connected to a laptop running Sysmac Studio ladder logic editor with I/O configuration panels open
omronsysmac studioplc programming

Omron Sysmac Studio: A Practical Getting-Started Guide

Learn how Omron Sysmac Studio works, how to set up your first NJ/NX project, configure I/O, write ladder and ST code, and connect to real hardware without the usual headaches.

Jul 21, 2026 · 9 min read

Flat vector diagram showing a PLC digital input module connected to a terminal block with a multimeter probing the input terminals to test a PLC input signal
plc troubleshootingplc inputsfault diagnosis

How to Test a PLC Input: Step-by-Step Guide

Learn exactly how to test a PLC digital input, from voltage checks at the terminal to forcing bits in software, with real field-tested steps.

Jul 21, 2026 · 9 min read

Flat vector diagram showing a laptop running a ladder logic simulation with ghost PLC rack and sensor icons connected by dashed lines, representing offline PLC simulation
ladder logicplc simulationcommissioning

How to Simulate Ladder Logic Without a PLC

Learn how to simulate ladder logic in Studio 5000, TIA Portal and CODESYS so you can catch logic errors before commissioning, with real examples and gotchas.

Jul 20, 2026 · 8 min read

Flat vector diagram of a PLC rack with a CPU module displaying a red fault LED and a diagnostic laptop connected for fault code reading
plc troubleshootingcpu faultplc fault diagnosis

PLC CPU Faults: How to Diagnose Them Step by Step

PLC CPU faults stop production cold. This guide walks you through reading fault codes, checking power, memory and I/O modules, and clearing faults safely.

Jul 20, 2026 · 8 min read

Flat vector diagram comparing normally open and normally closed contact symbols in PLC ladder logic rungs
ladder logicplc contactsnormally open vs normally closed

NO vs NC Contacts in PLC Ladder Logic: Full Breakdown

Confused about normally open vs normally closed contacts in PLC ladder logic? Learn what NO and NC mean in hardware vs software, with real wiring examples.

Jul 20, 2026 · 8 min read

Flat vector diagram comparing PLC, PAC, and DCS controller architectures side by side with I/O modules and network connections illustrated
plc vs pac vs dcscontrol system selectiondcs vs plc

PLC vs PAC vs DCS: Which Controller Do You Need?

PLC, PAC, and DCS all control industrial processes, but they are built around different assumptions. Here is how to tell them apart and pick the right one.

Jul 19, 2026 · 8 min read

Flat vector diagram comparing a PLC rack control system on the left with a distributed DCS cabinet architecture on the right, connected to process plant icons
plc vs dcsdcscontrol systems

PLC vs DCS: Key Differences and How to Choose

PLC vs DCS is one of the most debated choices in industrial automation. This guide cuts through the marketing and gives you a practical, field-tested comparison to help you pick the right platform.

Jul 19, 2026 · 9 min read

Flat vector diagram comparing XIC and XIO ladder logic contact symbols with bit-state labels showing how each instruction evaluates its tag
ladder logicallen-bradleystudio 5000

XIC vs XIO: Ladder Logic Contacts Explained

XIC and XIO are the two most fundamental contacts in Allen-Bradley ladder logic. Learn exactly how each evaluates its bit, where to use them, and the mistakes that catch beginners out.

Jul 19, 2026 · 9 min read

Flat vector infographic comparing TON on-delay, TOF off-delay and TP pulse PLC timer waveforms side by side with labeled input and output signal bars
plc timersladder logiciec 61131-3

TON vs TOF vs TP: PLC Timer Comparison

TON, TOF and TP are the three IEC 61131-3 standard timer types. Learn exactly how each one behaves, where each one fails you, and which to pick for your application.

Jul 19, 2026 · 8 min read

Flat vector diagram of S7-1200 TON TOF and TONR IEC timer function blocks connected to a PLC CPU icon
siemens s7-1200tia portalplc timers

S7-1200 Timers in TIA Portal: TON, TOF and TONR

Learn how TON, TOF and TONR timers work on the S7-1200 in TIA Portal, including IEC timer data types, instance DBs, preset syntax and real wiring gotchas.

Jul 18, 2026 · 9 min read

Flat vector diagram showing S7-1200 Global DB shared across multiple function blocks versus an Instance DB attached to a single function block in TIA Portal
siemens s7-1200tia portaldata blocks

S7-1200 Data Blocks: Global vs Instance DB Explained

Global and Instance DBs in the S7-1200 behave very differently. Learn which type to use, how memory is allocated, and how to avoid the classic commissioning mistakes.

Jul 18, 2026 · 9 min read

Flat vector diagram of an S7-1200 PLC with SM 1231 analog input module wired to a 4-20 mA transmitter, showing raw count and scaled engineering unit values
siemens s7-1200analog inputtia portal

S7-1200 Analog Inputs: Wiring and TIA Portal Setup

Learn how to wire, configure and scale analog inputs on the Siemens S7-1200 in TIA Portal. Real gotchas, address mapping and working ST code included.

Jul 18, 2026 · 8 min read

Flat vector comparison diagram of a Siemens S7-1200 compact PLC on the left and an S7-1500 modular PLC on the right with performance callout badges
siemenss7-1200s7-1500

S7-1200 vs S7-1500: Which Siemens PLC to Choose

S7-1200 vs S7-1500: compare CPU speed, memory, motion control, safety integration, PROFINET ports and real project cost so you choose the right Siemens PLC.

Jul 17, 2026 · 8 min read

Flat vector diagram of a PLC rack with a colour-coded memory map showing BOOL, INT, DINT and REAL data type cells
plc data typesplc interview questionsplc programming

PLC Data Types: Interview Questions Answered

Preparing for a PLC interview? These 15 questions on data types, addressing and memory layout cover exactly what hiring engineers ask, with field-tested answers.

Jul 17, 2026 · 9 min read