CTUD
Up/down counter — independent count inputs with separate at-preset and at-zero outputs.
When to use it
Use CTUD when something is both added to and taken from and the level in between matters — items in a buffer, vehicles in a bay, permits issued and returned.
Interface
The published port signature. This is the whole of what the block exposes to your program — the implementation body is not shown here and ships with the download.
Inputs
| Port | Type |
|---|---|
| CU | BOOL |
| CD | BOOL |
| R | BOOL |
| LD | BOOL |
| PV | INT |
Outputs
| Port | Type |
|---|---|
| QU | BOOL |
| QD | BOOL |
| CV | INT |
Validation evidence
- Tests
- 3
- Simulated scans
- 12
- Simulator
- v0.1.0
Complete IEC 61131-3 implementation with a published test suite that runs on the vplant simulator. The counts above are that suite, executed on this build.
- Conforms to IEC 61131-3
Download CTUD — free
Create a free Ri Tech account to download the block. You get the Structured Text body, the Rockwell Add-On Instruction (.L5X), the Schneider Control Expert DFB (.XDB), PLCopen XML and the datasheet.
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Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.