Light Curtain Muting Requirements

The terms muting and blanking are frequently used incorrectly.

Light curtain muting requirements.

Also called light screens optical guards and presence sensing devices safety light curtains offer freedom flexibility and reduced operator fatigue when compared with traditional guarding methods such as mechanical barriers sliding gates and pull back restraints nbsp. Muting for most of the stroke is required since the tooling will interrupt the light curtain during normal stroking of the press. Safety light curtains can be used in a variety of different modes such as muting blanking and floating blanking depending on the needs of the application. Safety related stop of hazardous motion initiated by a light curtain.

In material handling applications material is allowed to pass through the protective field without shutting down the machine. Also the status output for the mute light changes to green. The motion is allowed to coast to a stop. Muting shall be desabled as soon as the light curtain is cleared and not later than 4 seconds max.

Emergency stop of hazardous motion initiated by an e stop button. From the instant the first of the two muting sensors is cleared. Emergency stop of hazardous motion initiated by a light curtain. Muting allows the stock to bend and the operator to move through the light plane without stopping the press brake slide.

This post will help clarify the difference between the two so the correct safety light curtain functionality is chosen and the machine runs safely. After 3 seconds the status output and mute function turn off. Two sensor l type muting of a light curtain. At this point the light curtain is muted with the die no more than 1 4 above the workpiece or automatically turned off.

When enabled a function block is purple with a 3 second count down timer. Safety function requirements interrupting the light curtain stops and prevents hazardous. Our standard s difficulty here is that 1910 217 c 3 iii d allows muting on the upstroke and this application requires muting during over a much longer portion of the cycle. Light curtains must be properly integrated into the machine.

First we test the safety light curtain and latch reset with mute off. Safety light curtains are an advanced method of safeguarding personnel around many hazardous machines. Emergency stop of hazardous motion initiated by an e stop button. The timer monitoring the 4 seconds shall be a safety related item.

Muting light curtain monitoring relays allow the automatic temporary suspension of the safety function if certain conditions are met. Safety function requirements interrupting the light curtain stops and prevents hazardous motion by removal of power to the motor. This system executes a stop category 0 stop. Muting sensors shall be positioned beyond the light curtain in the dangerous area.