Circuit
Inspector
Click a terminal, switch, LED or wire in the diagram to learn what it does.
Timing trace
Live · last 6 sSix short lessons. Each one sets up the wiring for you, highlights the relevant parts of the circuit and waits until you have done the step.
Wiring module
Fault injection
Unit status
- Sim time
- 0 ms
- Input circuit
- Reset loop S33-S34
- Rlmax for this wiring
Event log
Test procedures
Each procedure runs against a fresh unit using the current wiring. Some override a setting (shown on the line) when they only make sense for that wiring. TP-04 is a training case: a pass there demonstrates the hazard.
Validation record
Plain-text record of the last run, for a commissioning file or ticket.
Data sheet values in use
Physical terminal layout
The diagram orders terminals for readability. On the real 22.5 mm unit, viewed from the front, they sit like this:
Glossary
- Safety contact (N/O, positive-guided)
- A relay contact whose N/O and N/C sets are mechanically linked so they can never both be closed. The unit uses the N/C side to check that K1 and K2 really dropped out.
- Input circuit (S11-S12, S21-S22)
- Where the E-STOP or gate switch contacts go. Channel 1 is S11-S12, channel 2 is S21-S22. Opening either channel de-energises the outputs.
- Reset / start circuit (S33-S34)
- Linked for automatic start, or wired through a reset button (and the contactors' mirror contacts) for a monitored manual start.
- Cross-short (short across contacts)
- A wiring fault that joins the two channels together. With "detection" wiring the channels sit at different potentials, so the unit sees the short and trips its electronic fuse.
- Feedback loop
- N/C mirror contacts of the external contactors wired in series with the reset circuit. If a contactor welds, the loop stays open and the unit refuses to restart.
- PL e / Cat. 4 / SIL CL 3
- The highest performance level under EN ISO 13849-1. Reaching it in your machine needs dual-channel wiring, cross-short detection and a feedback loop; the unit alone does not give it to you.
- Rlmax
- Maximum total cable resistance in the input circuit. Above it the unit cannot tell a closed switch from a long cable. 150 Ω single-channel, 15 Ω (DC) or 30 Ω (AC) dual-channel with detection.
What is modelled
Internal relays K1 and K2 in series on both safety contacts; monitored manual reset on a rising edge of at least 30 ms; automatic reset; the feedback loop; detection of earth faults, of cross-shorts in dual-channel-with-detection wiring, and of a relay that fails to drop out; ride-through of supply dips up to 20 ms; cable-resistance limits; infinite simultaneity between channels. Times are the typical values from the data sheet.
Not modelled: contact current and arcing, contact life, EMC, AC-specific behaviour beyond Rlmax, temperature derating. Fault detection is idealised (within a millisecond). Use the data sheet and operating manual for design decisions; this page is for training and for sanity-checking wiring and test sequences.
To add a wiring module, a test procedure or a lesson, add an entry to USE_CASES, TESTS or LESSONS in the page source; the UI builds itself from those tables.