What is SDP?
Two failure modes SDP protects against
- Blanking signal OFF while the scanner is still running.
- Laser running with normal blanking, but the scanner driver current is over-driven.
How it works?
A micro-controller monitors the galvo in real time — current, input signal and mirror position — so the circuit knows where the mirror actually is, which is also what makes scanner failure detection possible.
The monitoring score is updated every 25 milliseconds.
- If the score exceeds the preset threshold, a laser OFF signal is sent to the ILDA panel to stop laser output, and the scanner input is switched off.
- Laser and scanner stay off for 15 seconds, so the end user notices the scanner problem and the galvo can cool down.
- After 15 seconds the scanner input is switched back on and the laser output signal returns to the ILDA panel.
- The scoring system restarts.
Frequently asked questions
What does SDP do?
SDP monitors the scanner driver current and the laser blanking signal in real time, and cuts the laser and the scanner input when the galvo is driven outside its safe operating window.
How long does it hold the shutdown?
Laser output and scanner input stay off for 15 seconds before the system restores them and restarts the scoring system.
Why hold for 15 seconds?
The hold gives the user time to notice that the scanner has a problem, and lets the galvo cool down before the system restarts.
