The Muting function is the temporary automatic exclusion of the protection light curtain.This process is carried out in safety conditions in relation to the operating cycle of the machine.

This function is necessary when in the normal automatic cycle of a plant some machine parts or some objects must go through the light curtain without stopping the machine.

Let's cite the palletiser as an example since the product must pass through freely the area controlled by the lightguard while the access of a person must provoke the immediate machine stop.

Therefore it is necessary to create a safety system which is able to distinguish between :

• the materials authorized to go through the light curtain;

• people not authorized to go through the light curtain.

The muting function is possible with all El.IND.CO. light curtain model LC3 PXXX thanks to our BOX-MUT control unit.

Muting sequence "T" bidirectional with two cross sensors :

• The pack in transit occludes contemporary (max difference 2 seconds) the two Muting sensors and all that provokes the muting activation with the following temporary exclusion of the protection light curtain;
• The pack in transit occludes both the Muting sensors and the protection light curtain which is inactive;
• The pack in transit occludes the Muting sensors and frees the protection light curtain;
• The pack ends the Muting sensors occlusion and we have a reset of the protective functions of the light curtain.

If the muting sequence has not been respected the muting function will not be reactivated.
If the material is blocked in an anomalous way in the controlled areas of the lightguards the Muting must be inhibited and the maschine must be stopped. You can move the blocked materials by means of a manual command (override functions). The reset of the normal machine cycle must occur only after having checked the normal safety conditions with great care.

 

Following are the couples of the light curtains most commonly used in palletizing.