A comprehensive set of Excel tools for designing state-based control at Unit Module level — from I/O assignment and root tag definition through to step logic, transitions, CCM Step Interaction Matrix, and EM simulation.
P6 is the engineering heart of the CDL pipeline. Every design decision made here — steps, transitions, alarm setpoints, CCM assignments — flows directly into P7 ACM for automatic DCS code generation. The FRS is both the specification and the code generation source.
The Functional Requirement Specification describes what the control system must do to satisfy the URS requirements — without specifying how it is implemented in the DCS. It is the engineering bridge between the owner's requirements (URS) and the detailed implementation design (DDS/ACM code).
P6 takes the auto-generated FRS files from P5 — pre-populated with tags, limits, LOA classifications, and step frameworks — and completes the full functional design: I/O allocations to CM and CCM modules, step logic, transition conditions, and the CCM Step Interaction Matrix that drives code generation.
Pre-populated with tags (B1), operational limits (B3), LOA classification (A3), and Startup/Run/Shutdown step framework (A5) from the URS.
Imported to develop the Step‑CCM Matrix in section C5 — connecting the SOP step structure to CCM control actions automatically.
Operating Trend step list imported as the C2‑Steps foundation — Startup, Normal Run, and Shutdown steps pre-loaded for engineering team refinement.
Project-specific Control Module and Complex Control Module libraries developed in P5 — the building blocks assigned to each step in C5.
The P6 FRS Engine covers all fourteen sections of the ISA‑106 Functional Requirement Specification — organised into three groups that progress from high-level UM definition through to step-level control logic and simulation-ready code.
Unit Module scope, context diagram, SOP reference, and open issues register
Tag assignment, root tag mapping, calculations, alarm definitions, and code stubs
State machine design, transitions, CCM interaction matrix, diagrams, and final code generation input
The CCM Step Interaction Matrix in section C5 is the most important single artefact in the FRS. It defines, for every step, which Control Modules and Complex Control Modules are active — and what setpoint or command state they operate at.
This matrix is not just a documentation tool. It is the structured data input that P7 ACM reads to generate the complete DCS step logic code. Every row is a CCM. Every column is a step. Every cell is an active or inactive state with an associated setpoint.
P6-D and P6-E in the document library cover building and reviewing this matrix interactively — including a dynamic visualisation mode (P6-E) that lets engineers step through each state and visually confirm which CCMs are active.
| CCM / Step | S01 | S02 | S03 | R01 | D01 | D02 |
|---|---|---|---|---|---|---|
| FIC‑100 Feed | ||||||
| TIC‑100 Temp | ||||||
| PIC‑100 Press | ||||||
| P‑100 Feed Pump | ||||||
| XV‑100 Isolation |
Beyond the UM step design, P6 includes a PM‑UM‑EM design workflow (documented in P6-J, P6-K, and P6-L) for designing Generic Equipment Modules and simulating the combined UM‑EM logic before handing off to P7 ACM.
Simulation in P6 validates that step transitions and CCM interactions are logically consistent — catching design errors before they become code bugs in the DCS. This stage dramatically reduces commissioning time and rework.
Define the physical and logical structure of Equipment Modules within the Unit Module — mapping each EM to its associated CMs and CCMs from the User Library.
Construct the Generic Equipment Module template — a reusable EM definition that can be instantiated for all Equipment Modules of the same type in the Plant Area.
Run the UM‑EM simulation to step through each state, verify CCM activations and transitions, and confirm the step logic is consistent and complete before ACM code generation.
Final review of the p-Code and data dictionary — confirming all tags, CCM assignments, and step logic are complete and consistent before the FRS is locked for P7 ACM.
P6 has the most comprehensive document library in the CDL suite — twelve guides covering every aspect of FRS development from work process overview through to simulation and final review. Use your browser back arrow to return after reading.
A comprehensive walkthrough of the full P6 FRS Engine is available by Zoom. Contact us at info@CtrlDesigner.com with your company email to request a session.
Available via our online store or by invoice. P6 is typically used together with P5 URS Builder — service engagements covering both phases are available for teams tackling their first ISA‑106 FRS project.