Curious about what PLC programmers actually do all day? The answer depends on whether you are in the office, on-site commissioning, or troubleshooting an emergency call-out. Here is a realistic look at a typical day across different scenarios.
Office Day — Project Development
08:00 — Arrive and review emails. Check for overnight alarms from remote sites, respond to client queries, and review the project schedule.
08:30 — Morning standup. A fifteen-minute team meeting to discuss progress on current projects. Each engineer shares what they worked on yesterday, what they plan to do today, and any blockers.
09:00 — PLC programming. This is the core of the day. You might be developing ladder logic for a new conveyor system, writing structured text for a batch recipe manager, or configuring function blocks for a motor drive interface. You work in TIA Portal, Studio 5000, or whichever platform the project requires.
12:00 — Lunch break. Step away from the screen. Many engineers use this time to catch up on industry news or chat with colleagues about technical challenges.
13:00 — SCADA development. The afternoon might involve creating HMI screens, configuring alarm systems, or building data logging routines. Integration between the PLC and SCADA often requires careful attention to tag mapping and communication settings.
15:00 — Client call. A video call with the client to discuss the functional specification, clarify requirements, and walk through the proposed screen layouts.
16:00 — Documentation. Writing or updating the functional design specification, I/O schedules, and test procedures. Good documentation is essential but often underappreciated.
17:00 — Wrap up and commit code. Save your work, back up project files, and update the project management tool.
Commissioning Day — On-Site
06:00 — Travel to site. Commissioning often requires early starts and may involve staying away from home for days or weeks.
07:30 — Site induction and permits. Complete safety briefings, sign in, collect PPE, and obtain a permit to work on the control system.
08:00 — Download and test. Upload your program to the PLC, force inputs and outputs to verify wiring, and begin systematic testing of each function. This is where your program meets reality, and adjustments are always needed.
12:00 — Working lunch. On commissioning days, lunch is often eaten quickly in a site cabin or canteen while reviewing test results.
13:00 — Integration testing. Run the system with the mechanical and electrical teams, testing interlocks, sequences, and safety functions. Communication with other trades is critical here.
16:00 — Snag list review. Document issues found during testing, prioritise fixes, and plan the next day's activities.
18:00 — Evening programming. If commissioning is behind schedule, you might spend the evening making program changes ready for the next day's testing. Late finishes are common during commissioning periods.
Emergency Call-Out
Sometimes the phone rings at 2 AM because a production line has stopped and the night shift cannot identify the fault. You connect remotely via VPN, diagnose the issue through PLC diagnostics and alarm logs, guide the on-site technician through the fix, or drive to site if remote resolution is not possible.
The Reality
PLC programming is not a nine-to-five desk job. It involves a mix of office-based development, on-site commissioning, client interaction, and occasional unsociable hours. However, the variety, problem-solving challenges, and satisfaction of seeing your code control real machines make it a genuinely engaging career.
The engineers who thrive are those who enjoy learning continuously, communicating across disciplines, and tackling problems that rarely have textbook solutions.