Discussion in 'Laser Safety' started by benno, Oct 13, 2015.

  1. benno

    benno New Member

    quick , question.
    With PASS in the event of a failure, what is the time that PASS will signal shutdown and output a shutdown signal. Obviously the different hardware may
    thanks. Brian
  2. Pangolin

    Pangolin Staff Member

    Dear Brian,

    Thanks for the question. PASS responds to two kinds of "failures". One might be called "temporary" (or perhaps "low-priority") and the other might be called "permanent" (or perhaps "high-priority").

    A "temporary" failure would be, for example, a failure of the scanning system to maintain speed sufficient to maintain safety. The reason why this is deemed "temporary" is because, within an image, the beam might come to a momentary stop (for example on corners) after which the scanning would resume.

    In the case of a scanning failure, PASS will react as quickly as you have set it up to react. This is completely adjustable, but generally most people set this reaction time to around 1 to 1.5 milliseconds. Once scanning is resumed, PASS will enable the light to be emitted again.

    A "permanent" failure would be, for example, if the projector is putting out light when it's not supposed to be putting out light, or when the projector is putting out more light than you deemed safe with the "Maximum laser power" adjustment. In the case of this kind of failure, PASS responds immediately and aggressively. In the case of a "permanent" failure, PASS will: a) close the shutter; b) disable all colors; c) set the blanking output to zero; d) interrupt the signal path for the interlock (which should remove power from the lasers), and e) latch this condition until PASS is either reset or power is recycled to the projector.

    A full manual that describes PASS and how to setup the adjustments can be found here:

    Please let us know if you have any additional questions.

    Best regards,

    William Benner