Light Curtain Muting Requirements

Muting of a light curtain.

Light curtain muting requirements.

Light curtains optional functions as listed in annex a of iec 61496 part 1 must comply with annex a requirements. In material handling applications material is allowed to pass through the protective field without shutting down the machine. From the instant the first of the two muting sensors is cleared. The timer monitoring the 4 seconds shall be a safety related item.

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. First we test the safety light curtain and latch reset with mute off. Muting allows the stock to bend and the operator to move through the light plane without stopping the press brake slide. After 3 seconds the status output and mute function turn off.

Safety function requirements interrupting the light curtain stops and prevents hazardous motion by removal of power to the motor. Also the status output for the mute light changes to green. 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.

Two sensor l type muting of a light curtain. Next lets test the mute function. The motion is allowed to coast to a stop. Emergency stop of hazardous motion initiated by an e stop button.

At this point the light curtain is muted with the die no more than 1 4 above the workpiece or automatically turned off. Muting light curtain monitoring relays allow the automatic temporary suspension of the safety function if certain conditions are met. Emergency stop of hazardous motion initiated by a light curtain. Muting sensors shall be positioned beyond the light curtain in the dangerous area.

When enabled a function block is purple with a 3 second count down timer. 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. The terms muting and blanking are frequently used incorrectly. 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. Light curtains must be properly integrated into the machine. Safety light curtains are an advanced method of safeguarding personnel around many hazardous machines. Safety function requirements interrupting the light curtain stops and prevents hazardous.