mute sensors and safety relay

I am studying UE410 Flexi-mu. I read a lot about it and I still am not sure exactly how the light curtain muting works. My work has the exact setup as the picture.

So, what keeps the safety relay safety outputs from being interrupted when the mute sensors detect parts and when the parts break the light curetain?

My guess is that the two sensors being triggered means it's the parts, and only one sensor being triggered means a human? What about parts that have similar shape as a human?

When the relay's S3 & S4 are ON (two sensors triggered) the light curtain input S1 & S2 remains ON although the light curtain sends triggered signal?

Thank you for your help.

the 3rd angle is a bit misleading
the Hazard Side is where the beams are to be broken.
this is a timed function so if they are out of sync. they don't mute.
Access from the output side of the guard is not muted.
- LOGIC
if the part sensors are not broken then freed before the guard re-guards the system will fault

I'm at work and checked out the relay again. Correction; when I said S1,S2, S3, S4, I meant I1, I2, I3, I4. I3 and I4 are the mute sensors. I1 and I2 are the inputs from the light curtain.

Anyway, I found out that when I3 & I4 were ON (meaning, the mute sensors were triggered), the light curtain input being triggered (therefore cutting the safety input signal to the I1 & I2) does NOT affect the relay outputs. So, I guess I answered my own question.

But I still don't know what that lamp in the picture is supposed to do.

unsaint32 said:

But I still don't know what that lamp in the picture is supposed to do.

Click to expand...

In Australia and I think USA it is Mandatory to have a Monitored Mute Light - if the Globe is blown it will also lockout the guard