The world's most common industrial protocol in its two dominant forms — framing, addressing, gateways, and the mistakes that break integrations.
PLCs
Programmable logic controllers, programming (IEC 61131-3), and control hardware.
Ladder, function block, structured text, and the rest — what each of the five languages is good at and how shops actually mix them.
IndexModbus specifications and resources (modbus.org)
The Modbus Organization: current specifications for Modbus RTU, ASCII, and TCP, plus conformance and developer resources.
IndexPLCopen: motion, safety, and IEC 61131-3 libraries (plcopen.org)
PLCopen: IEC 61131-3 motion control libraries, safety, OPC UA function blocks, and coding guidelines.
IndexAutomation.com — news and resources (automation.com)
Automation.com: industrial automation news, tutorials, and vendor coverage from the ISA-affiliated publication.
IndexThe Automation Blog — PLC & HMI tutorials (theautomationblog.com)
Shawn Tierney's long-running PLC and HMI tutorial site: reviews, training, and plain-spoken controls commentary.
IndexABB Control Systems — 800xA & Freelance (abb.com)
ABB Control Systems: the 800xA DCS, Freelance compact DCS, PLC automation, and related lifecycle services.
Terms in this topic
- Functional safety
- Failure-tolerant design quantified by SIL ratings.
- IEC 61131-3
- Standard for the five PLC programming languages.
- PID loop
- The standard feedback control algorithm.
- PLC
- Rugged deterministic controller running scan-cycle logic.
- PLCopen
- Standard PLC libraries for motion and safety.
- SIL
- Quantified reliability target for safety functions.