What is a PLC and why does an electrician need it
A PLC (Programmable Logic Controller) is an industrial computer that controls equipment: conveyors, pumps, ventilation, lighting, machine tools. Where control logic was once built with relays and contactors, it's now all moved into a PLC program.
For an electrician, knowing PLC programming is a ticket to the world of automation. Demand for automation engineers is growing in Russia, India, and globally. An automation engineer's salary is typically 1.5–2× that of an installation electrician.
The 5 IEC 61131-3 languages
The international standard IEC 61131-3 defines 5 PLC programming languages. An electrician will find it easiest to start with those that resemble electrical diagrams:
- LD (Ladder Diagram) — looks like an electrical schematic: contacts, relay coils, timers. Ideal for electricians — you already know how to read such diagrams.
- FBD (Function Block Diagram) — functional blocks. Connect blocks (AND, OR, timers, counters) with lines — just like an automation functional diagram.
- ST (Structured Text) — similar to Python or Pascal. Great for complex math, loops, data processing. Most flexible, but requires programming skills.
- SFC (Sequential Function Chart) — describes process stages: step 1 → condition → step 2. Useful for cyclic processes.
- IL (Instruction List) — assembler-like. Being phased out, but still found in legacy Siemens S7-300 projects.
Recommendation: start with LD and FBD — as an electrician you already understand their logic. Then learn ST for complex tasks.
Where to start: hardware and software
Most accessible learning ecosystem:
- Siemens LOGO! — a mini-PLC with LOGO! Soft Comfort software (free). Perfect for first steps: lighting, gates, pumps.
- Siemens S7-1200 + TIA Portal — the industry standard. TIA Portal Basic is free.
- Allen-Bradley Micro800 + CCW — for the US/India market. Connected Components Workbench is free.
- CODESYS — free IDE, supports all 5 IEC 61131-3 languages. Download from codesys.com. The built-in PLC simulator lets you debug without any physical controller.
- OWEN PLC110/PLC160 — Russian budget controllers (≈$80), programmed in CODESYS. Popular in Russia and CIS.
- Segnetics (SMH4, Pixel) — Russian controllers with SMLogix IDE (FBD). Excellent for HVAC.
How GorkyCAD helps the automation engineer
When designing automation panels, GorkyCAD exports a BOM linked to PLC modules: digital inputs/outputs (DI/DO), analog inputs/outputs (AI/AO). This gives you a ready-made tag map for the PLC program. Instead of manually compiling a tag table, you get a structured list — and write the program faster.
3-month learning plan
- Month 1: install CODESYS, complete built-in LD and FBD tutorials. Build a "motor start-stop" and "motion-sensor lighting control" program.
- Month 2: buy a Siemens LOGO! or OWEN PLC110, set up a test bench with buttons and lights. Program and debug on real hardware.
- Month 3: learn HMI panels (Weintek, Siemens KTP), build a simple operator screen. Learn Modbus RTU/TCP — polling sensors and actuators.
After 3 months, you'll have a portfolio of 3–5 mini-projects and can apply for a junior automation engineer position.