Emergency stop¶
There are three independent ways to stop the motor. They differ in reaction time, in what they leave the system in, and in when each is appropriate.
The three stop paths¶
| Path | Action | Result | Use when |
|---|---|---|---|
| Software E-Stop | Press the red Emergency Stop button in ADCL WinSoft (VFD tab, right column) or in WindTunnelControl.ps1. |
Writes Control Word 0x0000 and REF1 = 0 — drive coasts to stop with no ramp. |
A person is in danger or hardware integrity is at risk and seconds matter. |
| Software ramp-stop | Press Stop Tunnel in the same panel. | Writes Control Word 0x0476 — drive decelerates per its programmed ramp (parameter 22.02 DECEL TIME). Motor remains energized but at zero RPM until commanded to start again. |
Normal end-of-run. |
| Mains kill | Operate the main switch on the wall to the building's three-phase feed for the tunnel. | Removes power from the VFD and motor. Coasts to stop; software loses Modbus connection. | Software is unresponsive, smoke or fire is present, or both stop buttons have failed. |
Sequence in a real emergency¶
- Stop the motor first — software E-Stop if you can reach it, mains kill otherwise. Stopping the motor stops the airflow, which stops the laser/smoke/projectile chain reaction.
- Then call for help — 911 (or 9-911 from a campus landline) if anyone is hurt, EH&S 949-824-6200 otherwise.
- Then secure the area — keep people out of the test section and the exhaust path until the motor is fully spun down.
- Then power off cleanly — mains kill if not already done, then close the control software, then de-energize ancillary equipment (laser, smoke generator, lights).
- Then log it —
WT_MS_<n>/debug_session.mdwith what happened, what you did, and the system state at the time.
Why the three paths are independent¶
- The software E-Stop writes Modbus registers over the lab Ethernet to the RETA-01 fieldbus adapter, which writes the drive's control word. It depends on the PC, the Ethernet adapter, the RETA-01, and the drive being powered.
- The software ramp-stop uses the same path but a different control word and therefore relies on the drive's deceleration ramp.
- The mains kill is a hard electromechanical disconnect upstream of everything else. It is the path of last resort because it is also the slowest to recover from (need to power-cycle, re-establish Modbus, etc.) and it does not give the motor a graceful ramp.
Pre-run verification¶
The first run of the day, with no model in the test section and the tunnel at low RPM (e.g. 100 RPM setpoint):
- Software ramp-stop → motor decelerates smoothly to zero.
- Restart, software E-Stop → motor stops faster than the ramp.
- Restart, mains kill → motor coasts down, drive loses Modbus (verify the control software reports the disconnect).
If any of the three paths fails, do not load a model and do not run a real experiment. Move to Troubleshooting or stop for the day.