Interview Questions for PLC Programmers: Complete Preparation
PLC programmer interviews typically combine technical assessment, practical demonstration, and behavioural evaluation. Being well-prepared across all three areas dramatically improves your chances of success. This guide covers what to expect and how to prepare.
Technical questions generally fall into several categories. Fundamental questions test your understanding of PLC architecture, scan cycle, I/O addressing, and memory organisation. Programming questions assess your ability to write and debug ladder logic, function block diagrams and structured text. Application questions test whether you can design a control solution for a given manufacturing scenario.
Common technical questions include topics like the difference between a normally-open and normally-closed contact, how a PLC scan cycle works, the difference between TON and TOF timers, how to implement a start-stop motor circuit, what happens during a PLC fault, and how to establish communication between a PLC and a SCADA system.
Practical tests are increasingly common, where candidates are given a PLC and asked to write a programme for a specific application on the spot. This is where hands-on training at EDWartens gives you a decisive advantage over candidates from lecture-based programmes. Our mock interview sessions simulate real interview conditions, including these practical assessments.
