Boolean search strings for controls engineers: PLC, DCS, SCADA and safety systems, with ISA CAP, CCST and the PE Control Systems
On this page
- Platforms, industries and credentials that change what a controls engineer search finds
- Ten Boolean strings by kind of controls work
- What LinkedIn, Indeed and Google actually support
- Narrowing by platform, industry and integrator or end user
- False positives worth excluding with NOT
- A worked example: three passes on a food plant controls search
- What a search cannot verify
- Questions people ask
A controls engineer designs, programs and starts up the systems that run machines and processes: PLC and HMI programs on a packaging or assembly line, DCS configuration and loop tuning in a chemical plant, SCADA for water utilities and pipelines, and safety instrumented systems. The title collides hard. "Controls" also means financial internal controls, project controls (cost and schedule), quality control and access control, and "automation engineer" is also a software test title. As of November 2026, the blocks that do the most work are the control platform the client runs, the industry, and the stage of the work: design and programming, commissioning at a customer site, or supporting a running plant.
Below are ten strings by kind of controls work, and what LinkedIn, Indeed and Google support as of November 2026. For power and building electrical design, see Boolean search strings for electrical engineers; for the engineers who own the production process, see Boolean search strings for manufacturing engineers; for the technicians who troubleshoot PLCs on shift, see Boolean search strings for maintenance technicians.
Platforms, industries and credentials that change what a controls engineer search finds
| Kind of controls work | Words candidates write | Platforms and standards they name |
|---|---|---|
| Machine and line controls (discrete) | PLC programming, ladder logic, HMI screens, motion control, servos, VFDs, safety PLC | Allen-Bradley, Studio 5000, RSLogix, Siemens TIA Portal, Step 7 |
| Process control | DCS, PID loop tuning, control narratives, alarm management, batch control | DeltaV, Experion, Yokogawa, ISA-88 |
| SCADA and utilities | SCADA, RTUs, telemetry, historians, remote sites | Ignition, Wonderware, AVEVA, DNP3, Modbus |
| Safety instrumented systems | SIS, SIL verification, safety requirements specification, cause and effect | IEC 61511, ISA 84, LOPA |
| Integration and commissioning | Control panels, I/O lists, factory acceptance tests, site acceptance tests, startup | Integrator project work, customer sites |
| OT cybersecurity | ICS security, network segmentation, OT networks | ISA/IEC 62443 |
- The title has many forms. O*NET's mechatronics engineers profile lists reported titles including Automation Engineer, Control Systems Engineer, Controls Engineering Specialist and Process Controls Engineer, as of November 2026. Controls engineers also come from electrical, mechanical and chemical engineering degrees, and some from the technician side.
- ISA CAP. ISA's Certified Automation Professional page describes a four-hour exam with 175 multiple-choice questions and says passing candidates are listed in the ISA Credential Directory. Its requirements page asks for five years in automation with a four-year technical degree (7,500 documented hours) or ten years with a two-year degree or none.
- ISA CCST for the technician route. ISA's Certified Control Systems Technician program has three levels, with five, seven and 13-year minimum education and experience requirements. Engineers who started as instrument or controls technicians often list it.
- The PE Control Systems is rare and annual. NCEES says the PE Control Systems exam is computer-based, has 85 questions, is designed for engineers with at least four years of post-college experience and is given once a year, with the next date April 14, 2027, as of November 2026. Search it only when the client needs a licensed engineer, and confirm the license with the state board.
- 62443 marks OT security work. ISA describes the ISA/IEC 62443 series as requirements and processes for securing industrial automation and control systems, and runs a certificate program built on it. Controls engineers moving into OT security write 62443; IT security staff mostly do not.
Ten Boolean strings by kind of controls work
Swap in the platform, industry and metro from your own intake; these are examples. Search on the work and the credentials, never on a term that stands in for age, sex, race, religion, national origin, disability or veteran status.
Machines and production lines
1. PLC controls engineer on Rockwell — LinkedIn Recruiter, Job titles + Keywords filters
("controls engineer" OR "automation engineer" OR "control systems engineer") AND ("studio 5000" OR rslogix OR "allen-bradley" OR "allen bradley" OR controllogix) AND (hmi OR "ladder logic" OR commissioning) NOT ("test automation" OR "internal controls" OR "project controls")
2. Siemens controls engineer — LinkedIn general search
("controls engineer" OR "automation engineer" OR "plc programmer") AND ("tia portal" OR "step 7" OR "s7-1500" OR wincc) AND (plc OR profinet OR "motion control")
3. Motion and robotics controls engineer — Indeed Smart Sourcing
("controls engineer" OR "automation engineer" OR "electrical controls engineer") AND skill: (plc OR servo OR "motion control" OR "robot integration") AND (packaging OR assembly OR "material handling") NOT ("test automation" OR selenium)Process control, SCADA and safety systems
4. DCS process control engineer — LinkedIn general search
("process control engineer" OR "process controls engineer" OR "dcs engineer" OR "control systems engineer") AND (deltav OR experion OR yokogawa OR "distributed control system") AND ("loop tuning" OR pid OR "control narrative" OR "alarm management")
5. SCADA engineer for water or pipelines — LinkedIn general search
("scada engineer" OR "controls engineer" OR "automation engineer") AND (scada OR rtu OR telemetry) AND (wastewater OR "water utility" OR pipeline) AND (ignition OR wonderware OR aveva OR dnp3 OR modbus) NOT (helpdesk OR "it support")
6. Safety instrumented systems engineer — LinkedIn Recruiter, Keywords filter
("sis engineer" OR "functional safety engineer" OR "process control engineer" OR "controls engineer") AND ("safety instrumented" OR "iec 61511" OR "isa 84" OR "sil verification") AND (hazop OR lopa OR "safety requirements specification")Integration, credentials and X-ray
7. Integrator commissioning engineer — LinkedIn general search
("controls engineer" OR "automation engineer" OR "project engineer") AND ("system integrator" OR integrator OR "control panel") AND (commissioning OR startup OR "factory acceptance" OR "site acceptance")
8. Certified or licensed controls engineer — LinkedIn Recruiter, Keywords filter
("controls engineer" OR "automation engineer" OR "control systems engineer" OR "instrumentation engineer") AND ("certified automation professional" OR "isa cap" OR ccst OR "professional engineer" OR "pe license")
9. Public profiles by platform and metro — Google X-ray
site:linkedin.com/in "controls engineer" "plc" "hmi" "greenville" -jobs -recruiter -"internal controls"
10. Recent public resumes with commissioning work — Google X-ray, filetype and date search
filetype:pdf "controls engineer" resume "ladder logic" "commissioning" after:2025-01-01 -template -sampleWhat LinkedIn, Indeed and Google actually support
LinkedIn's Boolean help page requires capital AND, OR and NOT, supports quotes and parentheses, evaluates quotes first, then parentheses, NOT, AND and OR, and does not support wildcards, as of November 2026, so "controls engineer," "control engineer" and "control systems engineer" each need writing out. The same page says the + and - operators are not officially supported, and it does not say how a hyphen inside a word is matched, so string 1 carries both "allen-bradley" and "allen bradley"; test "s7-1500" the same way. LinkedIn Recruiter's Boolean page lists "and" among the stop words ignored in Keywords, which loosens "instrumentation and controls engineer," so string 8 uses "instrumentation engineer" instead; it also warns that too many facets in one query can cause a search result issue.
Indeed's repair
and maintenance guide documents the skill: field used in string 3 and a
fieldofstudy: field. Controls engineers come from electrical, mechanical, chemical and
mechatronics degrees, so a single fieldofstudy: value empties the search; leave it out unless the
client insists. Google's search operators
page documents quotes, site:, the minus sign, filetype: and the
before: and after: date operators, but not OR, so strings 9 and 10 use none.
Narrowing by platform, industry and integrator or end user
For programming roles, the platform is the must-have: a Rockwell plant rarely wants to train a Siemens-only engineer, and a DeltaV site rarely takes someone who has only written ladder logic. Industry comes next. Packaging, food and automotive lines talk about OEE, changeovers and motion; chemical and pharmaceutical plants talk about loops, batch control and alarm rationalization; utilities talk about remote sites and telemetry.
Then ask whether the client is an integrator or an end user. Integrators build panels and programs in the shop and start them up at customer sites, which means travel; end users want someone who supports their own lines and takes the call at 2 a.m. Seniority shows in ownership: "lead controls engineer," "wrote the control narrative," "developed our programming standards" and "led the startup," against "modified existing logic" and "assisted with commissioning." LinkedIn's premium search filters page says Years of Experience and Seniority Level are only in Recruiter and Sales Navigator.
False positives worth excluding with NOT
- Internal and financial controls. Auditors and SOX testers write "controls," "control testing" and "control design." Exclude "internal controls," sox and audit. Finance controllers are a separate search; see Boolean search strings for controllers.
- Project controls. Cost and schedule engineers on construction and energy projects are titled "project controls engineer" and write Primavera P6 and earned value. Exclude "project controls," p6 and "earned value."
- Software test automation. "Automation engineer" is a common QA title. Exclude "test automation," selenium and cypress whenever the automation title is in the OR block.
- Building automation and HVAC controls. BAS technicians and engineers write controls, programming and commissioning about building systems. Exclude "building automation" and "bas technician" for plant roles, unless the client wants them.
- Flight controls and embedded control. Aerospace "flight controls" and guidance, navigation and control engineers, and firmware engineers who write embedded control code, share the words. Exclude "flight controls" and firmware for PLC and DCS roles; for firmware, run an embedded engineering search instead.
- Other kinds of control. Quality control, document control, access control and inventory control profiles all write "control." Exclude each phrase when "control" stands alone in a string.
- Technicians, when the role is engineering. Maintenance and instrument technicians list PLCs at the troubleshooting level. Exclude technician only if the client will not consider someone moving up.
A worked example: three passes on a food plant controls search
An invented search, shown as it actually gets narrowed.
Intake: A food and beverage plant running Allen-Bradley PLCs needs an in-house controls engineer to own line upgrades, write and modify Studio 5000 logic and HMI screens, and support production on call. Not looking for financial controls staff, test automation engineers or building automation technicians.
Pass 1: "controls engineer": a large mix of PLC engineers, project controls
staff, internal controls auditors, building automation technicians and flight controls engineers.
Pass 2: ("controls engineer" OR "automation engineer") AND ("studio 5000" OR
"allen-bradley" OR controllogix) NOT ("internal controls" OR "project controls" OR "test automation" OR
"building automation"): Rockwell engineers, though many work for integrators and move to a new site
every few weeks.
Pass 3: add AND ("food and beverage" OR "food manufacturing" OR packaging OR "line
upgrades"). Those words tend to come from engineers who have worked inside a plant on its own lines.
The list is short enough to call, and the screen asks about their last line upgrade: what changed in the
logic, how they tested it and how they fit it into the downtime window.
The platform block found Rockwell engineers; the industry block found the ones who stay with the line after startup. Add the industry block once the platform block has done its work.
What a search cannot verify
A string can find someone who names the right platform, industry and credential. It cannot show whether they wrote a program from scratch or edited someone else's, whether they commissioned a system alone, or whether a CAP or PE is current. Check ISA credentials in the ISA Credential Directory and licenses with the state board, then use the electrical engineer phone screen questions for the first call and the interview guide for manufacturing roles for the plant loop. For the environmental and safety staff the same plants hire, see Boolean search strings for EHS specialists.
Questions people ask
What is a good Boolean string for a PLC controls engineer?
Name the control platform the client runs, not just the title. For a Rockwell plant, for example: ("controls engineer" OR "automation engineer" OR "control systems engineer") AND ("studio 5000" OR rslogix OR "allen-bradley" OR controllogix) AND (hmi OR "ladder logic" OR commissioning) NOT ("test automation" OR "internal controls" OR "project controls"). For a Siemens plant, swap the middle block for TIA Portal and Step 7.
Why does a controls engineer search return auditors and project schedulers?
Because "controls" is also the word for financial internal controls (SOX testing and audit) and for project controls (cost, schedule and earned value on construction and energy projects). Exclude "internal controls," sox, "project controls" and "earned value" with NOT, and require plant words such as PLC, HMI, DCS or commissioning.
Which certifications do controls engineers hold?
Few hold any, so treat credentials as optional OR terms. The most specific are ISA's Certified Automation Professional (CAP), which asks for five years in automation with a four-year technical degree or ten with a two-year degree or none, and ISA's Certified Control Systems Technician (CCST) for those who came up as technicians. NCEES offers a PE Control Systems exam once a year, next on April 14, 2027, as of November 2026.
How do I find controls engineers who will travel for commissioning?
Search the integrator vocabulary: "system integrator," "factory acceptance," "site acceptance," startup and commissioning. Engineers who work for integrators write those words because they build systems in the shop and start them up at customer sites. Confirm the actual travel share on the first call, because no profile states it reliably.