Facts 2026-07-24.2
Reviewed 2026-07-24Implemented, not aspirational
Supported PLC instruction subset
The tested common runtime, data operations and dialect-specific syntax accepted by the current learning environment.
Common runtime subset
“Supported” means the current parser/runtime path contains an implemented operation and it is covered by repository tests. It does not mean every spelling is accepted in every dialect, nor that vendor status bits and firmware side effects are emulated.
| Instruction family | Implemented subset | Boundary |
|---|---|---|
| Boolean and rung logic | Normally open/closed contacts, AND, OR, NOT, series/parallel logic and output assignment | Spelling and addressing vary by dialect; graphical editing is translated to the common runtime. |
| Coils and state | Output energize plus set/reset or latch/unlatch forms where the dialect exposes them | Vendor retentive-memory and power-cycle behavior is not firmware-emulated. |
| Timers | TON, TOF and TP in the common IEC runtime | Not every vendor parser or renderer exposes every timer form; time advances on the teaching clock. |
| Counters | CTU, CTD and CTUD in the common runtime | Vendor mnemonics and reset/load inputs differ. Some mnemonic subsets currently expose CTU only. |
| Edges | R_TRIG and F_TRIG | Execution is deterministic in the browser, not tied to a physical controller task. |
| Data operations | MOV, ADD, SUB, MUL, DIV and MOD | Available forms depend on the parser; overflow and vendor status-bit behavior are not universally emulated. |
| Comparisons | EQ, NE, GT, GE, LT and LE | The supported scalar type subset is documented below; vendor-specific compare families are out of scope. |
| Process control | PID function block in the common runtime | A teaching model for loop behavior, not the proprietary tuning, scheduling or anti-windup behavior of every vendor. |
Scalar and block types
Current common AST types:
BOOLINTDINTREALTIMEWORDDWORDTONTOFTPCTUCTDCTUDR_TRIGF_TRIGPIDA precise way to read this list
The common runtime is broader than some vendor-style input parsers. For example, Mitsubishi, Omron and Delta learning syntax currently centers on contacts, coils, TON-style timers, CTU-style counters and basic word operations. Check the dialect matrix before assuming a block is accepted in a particular mnemonic form.
Not represented as “supported”
- Complete vendor instruction catalogs or firmware quirks
- Safety signatures, SIL/PL validation or safety-runtime behavior
- Motion-control axes, servo tuning and vendor motion planners
- Native vendor project import/export
- Hardware configuration, module profiles and fieldbus commissioning
- Real-time task jitter, watchdog behavior or controller performance certification
Found a mismatch?
Send the URL, facts version, expected behavior and observed behavior. Product and documentation corrections are reviewed together.