Read a Factory P&ID for WinCC Explorer SCADA Screen Design

Start with one factory process

A useful SCADA screen begins with an understanding of the plant. In this five-lesson exercise, water enters tank TK-101, pump P-101 transfers it through valve XV-101, and transmitter FT-101 measures discharge flow. LT-101 measures tank level. You will follow the same equipment from the drawing through to a WinCC Explorer process picture.

The illustrations are simplified teaching drawings, not an approved plant P&ID or a vendor screenshot. Their equipment identifiers, ranges and operating rules are exercise assumptions. In a real project, use the approved drawing legend, instrument index and control narrative.

Prepare WinCC Classic engineering access and a separate training project. The software references cover the WinCC Explorer/Graphics Designer workflow in WinCC V7.5 and V8.0; exact menus and available libraries depend on your installed release. This series does not use TIA Portal WinCC Unified.

Read the drawing in a repeatable order

1. Read the title block. Record the drawing number, revision and plant area before extracting tags. Add these details to your worksheet so another engineer can trace your decisions.
2. Trace material flow. Begin at the inlet, follow the tank outlet, pump suction, discharge valve and destination. Use the process arrows. A crossing line is not automatically a connected branch.
3. Identify equipment. Give every tank, pump and actuated valve its own row. Preserve the drawing identifier; a friendly caption such as “Transfer pump” can appear beside it.
4. Identify measurements. For this exercise, LT-101 is level and FT-101 is flow. Confirm these meanings against the project legend rather than treating the letters alone as proof.
5. Separate process and signal lines. Process piping belongs to the operator flow picture. Electrical or communication paths usually belong in a diagnostic view or engineering documentation.
6. Read the control narrative. The P&ID may show the equipment relationship without specifying restart behavior, command permissions, alarm delays or setpoints. List missing information instead of inventing it.

Build the equipment-to-screen register

For the teaching skid, use level in percent and flow in m³/h. Do not choose a PLC address yet. A drawing tag identifies a device; the PLC program and communication design determine its address and data type.

Convert the drawing into an operator screen plan

Sketch the tank on the left and the discharge destination on the right. Place P-101 and XV-101 along the actual flow path. Put the flow value beside its measurement location and the tank level beside TK-101. Reserve space for status text, navigation and an alarm summary.

Keep equipment names and the flow direction readable at the intended operator display resolution. It is acceptable to simplify bends and omit construction dimensions while preserving process meaning. A SCADA screen is a view of the process, not a scaled piping construction drawing.

Write three questions the finished display must answer: “Is water available?”, “Is the pump actually running?” and “Is flow reaching the destination?” These questions guide the later tag and symbol choices. A start command alone cannot answer the second question; it needs feedback.

Practice and check your result

Your task: redraw the training skid on paper or in a drawing tool, then create the four-row register above using your own descriptions. Mark each item as static equipment, live measurement, state indication or operator command.

• Every device in the sketch has a matching register row.
• You can trace the flow path without following signal wiring.
• The pump command and running feedback are separate requirements.
• Unknown ranges, permissions and alarm limits are explicitly marked for confirmation.
• A second learner can describe the transfer process using your sketch.

Common correction: if your sketch contains many decorative pipe details but no fault or measurement-quality information, simplify the drawing and add those operating requirements. Take this annotated plan into Lesson 2.