Topic
Engineering
38 guides across the knowledge base.
Program Organization
Structuring a controller program so that someone else can maintain it: a layout that follows the plant, one routine per job, standard device blocks, I/O mapped in one place, a fixed execution order, naming that means something, and comments that say why.
10 min readUpdated Sep 5, 2026
Unity Pro
Field notes on Unity Pro, the earlier name of Control Expert and the software behind most installed Modicon M340, Quantum, and Premium applications: versions, moving projects to Control Expert, keeping an old version alive, and the Concept and PL7 originals.
7 min readUpdated Sep 5, 2026
Studio 5000
Field notes on Studio 5000, the Rockwell Automation software for ControlLogix and CompactLogix: the version-to-firmware rule, side-by-side installs, project files, add-on instructions, online editing, documentation in the controller, source protection.
8 min readUpdated Sep 5, 2026
Legacy Systems
Keeping older controllers running and planning a migration: the families still found in water plants, the risks that grow each year, software to keep alive, batteries and memory, tested spares, the security problem, and a migration the plant can survive.
9 min readUpdated Sep 5, 2026
Engineering Units
Choosing and documenting the units a tag carries: where the unit is decided, how it flows from transmitter range to controller scaling to screen and historian, the conventions used in water and wastewater, and the mismatches that put a wrong number on screen.
7 min readUpdated Sep 5, 2026
Other Platforms
The SCADA and HMI products a water utility may meet beyond the common ones: Siemens WinCC, distributed control systems, independent SCADA products, hosted lift station monitoring, and open-source tools, and the questions that decide whether one belongs.
8 min readUpdated Sep 5, 2026
Differential Pressure Level
Measuring level in a closed or pressurized vessel with a DP transmitter: high and low side connections, dry legs and wet legs, zero suppression and elevation, the range calculation with a worked example, remote seals, and the density dependence.
10 min readUpdated Sep 5, 2026
Pressure Transmitter Installation
Where and how to install a pressure transmitter so it reads the process and not its own plumbing: tap location, mounting above or below the tap, isolation and bleed valves, line slope, pulsation, elevation, freeze protection, seals, vibration, and sun.
10 min readUpdated Sep 5, 2026
Aeration
Aeration in drinking water treatment: stripping carbon dioxide, hydrogen sulfide, radon, and volatile organics, and oxidizing iron and manganese ahead of filtration. The aerator types, what each needs from the control system, the pH shift, and the interlocks.
9 min readUpdated Sep 5, 2026
High Service Pumps
The pumps that carry finished water into distribution: types, the pump curve against the system curve, best efficiency point, the affinity laws and where a drive pays, parallel operation, valves, protection, and the efficiency monitoring that shows wear.
11 min readUpdated Sep 5, 2026
Patch Management
Applying updates to SCADA servers and clients without breaking the plant: vendor qualification, a monthly cycle with a test system, priority from the exposed edge inward, backups and rollback, emergency patches, and handling software that cannot be patched.
9 min readUpdated Sep 5, 2026
Change Management for OT
A change process sized for a utility control system: what counts as a change, the request with risk and rollback, owner approval, the window, backup before and verification after, the baseline update, the emergency path, and the record.
9 min readUpdated Sep 5, 2026
Poor Signal Margin
A path with too little signal above receiver threshold to survive rain, leaves, and inversions: the link budget from transmitter to receiver, the Fresnel zone, and why the margin is smaller than the study said. How to compute, measure, and add to it.
9 min readUpdated Sep 5, 2026
How to Read a P&ID
What a piping and instrumentation diagram shows, how ISA-5.1 tag bubbles and line types encode the control system, and how to trace a loop across sheets.
8 min readUpdated Sep 5, 2026
Control Narratives
What a control narrative is, what it must contain, how to write statements that can be tested, and how it drives programming, FAT, and the owner’s acceptance.
9 min readUpdated Sep 5, 2026
Sequences of Operation
Writing the ordered, step-by-step description of what a system does: states, transitions, timeouts, and the format that lets a programmer implement it and a tester verify it without interpretation.
8 min readUpdated Sep 5, 2026
Cause and Effect Matrices
The table that lists every trip condition against every action it causes: how to build one, what goes in the cells, how it distinguishes hardwired from software protection, and how it becomes the test.
7 min readUpdated Sep 5, 2026
Factory Acceptance Testing
Testing a control system before it leaves the shop: what must exist before the test, how the procedure is built from the narrative and the matrix, how the field is simulated, what is witnessed, and what the punch list and the sign-off mean.
9 min readUpdated Sep 5, 2026
Site Acceptance Testing
Proving the installed system with the real field: loop checks first, then end-to-end I/O, real communications, sequences on real equipment, alarms to real recipients, and failure modes on the real network, with the record that becomes the as-built.
8 min readUpdated Sep 5, 2026
I/O Lists
The document that ties the field to the controller: what every I/O list column means, how tags, terminals, and module channels are assigned, spare capacity rules, how the list drives the drawings and the program, and how to keep it true after commissioning.
9 min readUpdated Sep 5, 2026
Instrument Lists
The index of every measuring and final control device on a project: what the instrument list records, how it grows from the P&ID into specification sheets and calibration records, the columns that matter at each stage, and how it becomes the asset register the utility maintains.
8 min readUpdated Sep 5, 2026
Control Schematics
The ladder-style drawing of every control circuit in a panel: how a schematic is organized by line number, the conventions for contacts, coils, and cross-references, what belongs on a schematic and what belongs on a wiring diagram, and reading one under pressure.
9 min readUpdated Sep 5, 2026
Commissioning Checklist
From energization to handover: the sequence of commissioning activities for a control system, the prerequisites and records for each, who signs what, and the checklist that keeps a project from being declared finished while half of it has never been tested.
10 min readUpdated Sep 5, 2026
ISA Standards for Controls
The International Society of Automation standards a controls practitioner meets: ISA-5.1 symbols and tags, ISA-18.2 alarm management, ISA-101 HMI design, ISA-88 and ISA-95 for batch and enterprise integration, ISA-99 which became IEC 62443, ISA-20 specification forms, and how each is used on a water or wastewater project.
8 min readUpdated Sep 5, 2026
IEC Standards for Controls
The International Electrotechnical Commission standards a controls practitioner meets: IEC 61131 for programmable controllers and their languages, IEC 62443 for security, IEC 61511 for safety instrumented systems, IEC 60529 ingress protection ratings, the telemetry protocols, and how IEC and North American standards fit together.
8 min readUpdated Sep 5, 2026
Wiring Diagrams
The drawing that says where every wire goes: panel wiring and interconnection diagrams, and the conventions of wire numbers, conductor colors, terminal numbers, and cable numbers that make them readable. What belongs here versus on the schematic.
9 min readUpdated Sep 5, 2026
Panel Layouts
The drawing of what goes where inside a control panel: enclosure, back plate with every component to scale and keyed to the bill of material, wireways, terminals, door devices, and entries. The conventions, the required spacings, and the checks.
9 min readUpdated Sep 5, 2026
Cable Schedules
The list of every cable with what it is, where it runs, and where it lands: the columns, the numbering convention, types and signal classes, routes through conduits and trays, lengths, terminations, spares, and status from design through as-built.
8 min readUpdated Sep 5, 2026
Functional Descriptions
The system-level document that states what a control system does, organized from the overview down to each piece of equipment in one format: modes, control, setpoints, permissives, interlocks, alarms, sequences, and failure behavior, and how it is used.
10 min readUpdated Sep 5, 2026
Design Checklist
A review checklist for a control system design at each stage from concept to issued for construction: documents, architecture, controllers and I/O, panels and power, instruments, networks and security, SCADA and alarms, deliverables, and commissioning.
11 min readUpdated Sep 5, 2026
NIST Publications for Control Systems
The National Institute of Standards and Technology documents a control engineer will meet: the Cybersecurity Framework, the operational technology security guide, the control catalog, the digital identity guideline, and the incident handling guide.
9 min readUpdated Sep 5, 2026
Where the Logic Should Live: Controller, SCADA, or Relay
Every control decision has a home, and putting it in the wrong one is the root of most plants that are hard to operate. A rule for deciding what belongs in the controller, what belongs in SCADA, and what belongs in a relay.
9 min readUpdated Sep 5, 2026
What a Small Utility Should Ask Before Buying SCADA
A utility with a plant, a few dozen remote sites, and two operators on call is buying a system it will live with for twenty years. The questions that decide whether it works out, and they are not about features: licensing, staffing, and the exit.
9 min readUpdated Sep 5, 2026
Measure Before You Replace
Parts-swapping is the most expensive way to troubleshoot and the most common. A method for controls faults that starts with a measurement, splits the problem in half at every step, and ends with a cause instead of a coincidence.
8 min readUpdated Sep 5, 2026
The Control Narrative Is the Contract
Most control system disputes, delays, and disappointments trace to one missing document: a narrative that says, in plain language, and how it keeps paying after startup.
8 min readUpdated Sep 5, 2026
The Knowledge That Leaves With the Retiring Technician
Water and wastewater utilities are losing the people who know how their control systems actually work, and a practical program for capturing it while there is still someone to ask.
8 min readUpdated Sep 5, 2026
What Integrator Consolidation Means for a Small Utility
The regional controls integrator that built a utility system over twenty years is being bought, merged, or closed, and how to stop depending on any single firm for the system it owns.
7 min readUpdated Sep 5, 2026
As-Built Means Someone Walked the Panel
The drawings in the panel pocket are the ones from the bid set, and how a small utility keeps its drawings true after the integrator has gone.
9 min readUpdated Sep 5, 2026
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