Bridge Operator Reference
NORTHSTAR SHOW SYSTEMS
Bridge Operator Reference
Physical control panel quick-reference
v1.0 — May 2026
Bridge Operator Reference
The Bridge is the physical control panel for Northstar Show Systems. It connects to the Helm server via USB and provides hardware buttons and LED indicators for show control. This is the operator’s quick-reference for every button and LED on the panel.
Buttons
| Button | Label Color | Action | Notes |
|---|---|---|---|
| Show Start | Green | Starts the show (STOPPED → RUNNING) | Blocked if maintenance key is ON. Also fires the boot sequence. |
| Show Stop | Red | Stops the show (RUNNING → STOPPED) | Cancels all running sequences. Always works — panic stop. |
| Show Reset | Yellow | Resets the show (→ RESETTING → STOPPED) | Cancels all sequences. 5-second reset window with flashing LED. |
| Maintenance Key | Blue | Latching key switch for maintenance mode | ON: blocks start, triggers, and new schedules. OFF: normal operation. |
| Server Reset | Blue | 3-second hold: graceful HelmOS restart | Reloads config, resets state to STOPPED. Does not restart the service. |
LED indicators
| LED | Pin | Normal State | Meaning |
|---|---|---|---|
| Show Start | D8 | Solid green when show is RUNNING | Show is live |
| Show Stop | D9 | Solid red when show is STOPPED | Show is stopped |
| Show Reset | D10 | Flashing yellow (2 Hz) during RESETTING | 5-second reset window active |
| Maintenance | D11 | Solid when maintenance key is ON | Maintenance mode active — triggers blocked |
| Server Running | D12 | Solid when HelmOS is healthy | Slow blink (0.5 Hz) = HelmOS heartbeat lost for 15+ seconds |
| PC Ping OK | D13 | 200 ms pulse on each PONG | Confirms USB serial communication is active |
What to do if the Server LED is blinking slowly
A slow blink on the Server Running LED (D12) means the Bridge has not received a heartbeat from HelmOS for 15 seconds or more. This fail-safe activates automatically. Possible causes:
- HelmOS has crashed or is unresponsive. Check the Helm mini PC.
- The USB cable between Bridge and Helm is disconnected or loose.
- The NSSM service (HelmOS) has stopped. Restart it from Windows Services.
If HelmOS recovers, the LED returns to solid automatically once heartbeats resume.
Maintenance mode
Turn the maintenance key switch to ON before performing any physical work on the show floor. This prevents accidental triggers from schedules or other operators.
What still works during maintenance:
- Show Stop (panic stop)
- Show Reset (full reset)
- In-flight sequences run to completion
What is blocked:
- Show Start
- All manual triggers (Cuemaster buttons, API calls)
- New schedule-fired sequences