What does a controls technician do? PLCs, automation and building controls work explained

A controls technician owns the layer that makes equipment run itself.

The work moves in a loop: install the control components, program or load the controller, commission the system until it behaves as designed, then troubleshoot and maintain it when it does not.

Different employers weight the loop differently — some roles are install-heavy, some live on the support side — but the loop itself is the job.

On the install and commissioning side, the work starts on paper: control schematics, panel drawings and process diagrams.

From there it moves to hardware — mounting and wiring control panels, terminating the field devices the controller depends on (sensors, motor starters, variable frequency drives, operator interfaces), and catching where the drawings and the reality disagree before that disagreement becomes downtime.

Commissioning is the payoff step: proving out each sequence, confirming that safety interlocks behave, and documenting what the system actually does before handing it to operations.

On the support side, the day is diagnosis.

A machine faults, a process drifts, a drive trips — and the tech works from the symptom back to the cause, which may be electrical, mechanical or in the program.

That looks like a laptop with the controller software open one minute and a meter on a terminal the next.

It also includes program edits: small logic changes, alarm handling, and keeping records of what changed and why, because an undocumented change in a plant is a fault waiting for the next shift.

• Reading electrical and control schematics, panel drawings and process diagrams
• Installing and terminating control panels and field devices
• PLC and controller programming, program edits and backups
• HMI and operator-interface work — graphics, alarms and setpoints
• Motors, starters and variable frequency drives
• Troubleshooting live systems from symptom to cause
• Commissioning, startup and documentation

The settings are as varied as the list implies.

The role shows up anywhere equipment runs automatically — manufacturing and food-processing plants, packaging and automotive lines, water and wastewater treatment, commercial buildings on the building-automation side — and the employer can be the plant itself, an electrical or automation contractor, or a specialty integrator.

The title covers two related jobs with different equipment, different employers and a different feel day to day.

Industrial automation is machine control.

Programmable logic controllers run production machinery — conveyors, robotic cells, pumps, mixers, motors and drives — and the priorities are uptime, throughput and repeatable quality.

The environment is a plant floor.

The people you stand next to are industrial electricians and maintenance technicians, and when a line stops, everyone wants it running again immediately.

Building automation is environment control.

Controllers run heating, ventilation and air-conditioning equipment — air handlers, chillers, boilers, dampers and valves — plus lighting and energy management, in buildings built for people.

Titles like HVAC controls technician and BAS (building automation system) technician describe this side of the field.

The employers change too: mechanical and building-automation contractors, system integrators and in-house facilities teams rather than production plants.

The fundamentals transfer in both directions.

A controller is a controller; schematic reading, logic and methodical troubleshooting look similar from either side.

What changes is the equipment, the networks, the pace of a plant versus a building, and who you answer to when something stops.

People do move between the two worlds, but expect to relearn the product line, and treat the move as a lateral step into a new specialty rather than a promotion up the same ladder.

PLC technician is not a separate trade — it is the same job family with the emphasis moved onto the controller.

An employer hiring under that title wants the install-program-troubleshoot skill set centered on programmable logic controllers: loading and editing programs, adding logic when equipment changes, backing up and restoring programs, and deciding whether a fault lives in the wiring, a device or the code.

Employers pick whatever label fits their shop, and the same duties get posted as controls technician, controls tech, automation technician, automation controls technician, electrical controls technician or PLC technician.

When you read postings, the duties tell you more than the title does.

On this board, PLC technician listings are folded under controls technician so the titles do not split the search.

The one label that does mark a real boundary is engineer.

Controls engineer roles sit on the design side — specifying systems, selecting components and owning program architecture — while technician roles center on installing, supporting and maintaining the systems someone else designed.

The two work together constantly and people cross between them, but they are different jobs with different expectations — read the posting to see which one an employer means.

No single answer covers the role, because there is no single route in — but the honest answer starts with how much of the job is electrical work, and that varies by employer and site.

The overlap with the trade is real.

Controls work sits on electrical fundamentals: schematic reading, motor circuits, and safe work habits around energized equipment.

Industrial electricians and maintenance electricians already spend part of their week around PLCs, drives and control panels, which is why the move from the trade into controls is a story of its own — told properly in the guide to moving from electrician into controls, so this page does not retell it.

It is not the only shape of the role, though.

Controls techs also arrive from industrial maintenance and electromechanical work inside plants, and from mechatronics-style schooling — the next section covers the routes.

What employers screen for is less the label on your background than whether you can read the schematic, trace the circuit, work the controller software and diagnose methodically.

Licensing is the half of the question that varies by state.

BLS notes that most states require electricians to pass a test and be licensed, and that requirements vary by state.

How those rules reach controls-heavy work — and when a licensed electrician is required on the job — is exactly the kind of question each state answers differently, so this page does not generalize it.

Three routes cover the ground, and people arrive by all of them.

1. Through the electrical trade. Electrician apprenticeship and electrical maintenance experience build exactly the foundation the role sits on — schematics, motors, field wiring — and controls specialization grows out of plant exposure plus focused study on the controller side.
2. From inside a plant. Industrial maintenance, electromechanical and instrumentation-adjacent jobs put you next to the equipment every day; techs who take on the controller work gravitate toward the title from there.
3. Through school. Community and technical college programs in mechatronics, electromechanical technology and automation cover controllers, drives and instrumentation — the same subject areas the duties list above draws on, in both industrial and building-automation flavors.

Entry requirements are set by whoever is doing the hiring, so the fastest read on what a particular market wants is the postings themselves.

When you read them, watch which duties repeat and which software gets named; that is the local syllabus.

Whichever route you take, the screening is consistent in kind: schematic fluency, electrical fundamentals, comfort on the software side, and evidence you can troubleshoot methodically under pressure.

The two roles meet at the sensor.

Instrumentation technicians own the measurement side of a process: selecting, installing, calibrating and maintaining the instruments that read it — pressure, temperature, flow, level.

Controls technicians own the controller side: the logic and equipment that act on those measurements.

In process plants the boundary blurs enough that combined titles — I&C, for instrumentation and controls, and E&I, for electrical and instrumentation — exist to cover both.

The skill sets stack more than they compete: calibration and loop knowledge make a controls tech better at the controller's half, and program knowledge makes an instrumentation tech better at theirs.

The overlap reaches the pay data, too: our sources carry no separate BLS occupation for either title, and the closest reported one — electrical and electronics repairers, commercial and industrial equipment (SOC 49-2094) — is flagged as a common proxy for instrument and controls techs, which is why the section below leans on it.

BLS OEWS has no controls-technician series, so the honest figures come from the nearest proxies — each named, with its series:

• Electrical and electronics repairers, commercial and industrial equipment (SOC 49-2094) — the occupation the proxy figures use, flagged in the data as a common proxy for instrument and controls techs. Across all industries, OEWS put the May 2025 annual median at $74,090. In manufacturing the median was $77,160 (15,560 employed), and in petroleum and coal products manufacturing it reached $105,590.
• Electro-mechanical and mechatronics technologists and technicians — an adjacent BLS role family. The May 2025 median was $73,900 — against $63,190 for electricians (SOC 47-2111) the same month. BLS projects 3% employment change for the role family from 2025 to 2035, against 9% for electricians.

Read those as national medians for whole occupations, not offers — the manufacturing and refinery figures above show how much industry moves them — and note that OEWS does not split union from non-union pay.

The controls technician salary page shows the proxy figure and what it does and does not cover, and current openings are in controls technician jobs.

Career information, not licensing, legal, code or safety advice — confirm licensing questions with your state electrical licensing board.