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PFC Charts (ISA-88)
Render ISA-88 / IEC 61512 Procedure Function Charts from ```pfc fenced code
blocks directly in the VS Code Markdown preview — themed inline SVG, no external
services, Mermaid-style.
```pfc
pfc Simple Batch
step "Charge Reactor" :operation
trans "level >= 500L"
step "Heat" :operation
step "Hold" :operation
trans "time elapsed"
step "Cool" :operation
```
Open any Markdown file and run Markdown: Open Preview (Ctrl+Shift+V, or
Ctrl+K V for side-by-side). Every ```pfc block renders as a chart that follows
your active color theme.
Features
Full PFC language — steps with ISA-88 levels (phase → operation → unit procedure →
procedure), explicit and implicit transitions, and encapsulation.Structured sequences — simultaneous (parallel, AND) and selective (selective,
OR) branch blocks, arbitrarily nested.Coordination — equipment allocation, sync (rendezvous) and transfer
(material handoff) connectors between branches or lanes.Cycles & jumps — whole-chart loop, conditional goto retries, and multi-lane
concurrent processes that each loop independently.Notes — boxed annotations attached to any step.Drill-down links — link "charge.md" makes a step clickable, opening the note with
its lower-level chart right in the preview.Theme-aware — colors map onto VS Code theme variables (light / dark /
high-contrast).
Syntax at a glance
Construct
Example
Step + level
step "Charge" :operation
Explicit transition
trans "level >= 500L"
Simultaneous (AND)
parallel … branch … end
Selective (OR)
selective … branch … end
Allocation
alloc "Reactor 1 or 2"
Synchronization
sync S1 (paired across branches)
Material transfer
transfer T1 out / transfer T1 in
Note
note "operator confirms"
Loop / retry
loop · goto STEP_ID
Concurrent lanes
concurrent … process "Lane" … end
Same-width boxes
uniform-width (anywhere in the chart)
Drill-down link
link "charge.md#phases" (after an operation or higher step)
sync, transfer, and note attach to the step directly above them.
Example — concurrent lanes
```pfc
pfc Machine Cycle
concurrent
process "Main Cycle"
step "Operation 1" :operation
step "Operation 2" :operation
sync R
process "Outfeed"
step "Wait for cycle" :operation
sync R
step "Operation 5" :operation
end
```
Notes
Works entirely offline; no telemetry, no network calls.
Charts render as inline SVG in the preview and export/print with the document.
License
MIT
