Light Curtain Muting Circuit

If it s muted for too long the curtain will allow access to the safety hazard and obviate its purpose.

Light curtain muting circuit.

Safety light curtains reliably and cost effectively protect against access into hazardous points and areas. The range from small and compact types to extremely robust and resistant variants that withstand special ambient conditions up to the highest safety level. Muting sensors shall be positioned beyond the light curtain in the dangerous area. The light curtain monitors its internal circuitry and its ossd ou tputs for faults.

The timer monitoring the 4 seconds shall be a safety related item. Muting or bypassing of the psd during the upstroke of the press slide is permitted for parts ejection circuit checking and feeding. Muting light curtain monitoring relays allow the automatic temporary suspension of the safety function if certain conditions are met. The terms muting and blanking are frequently used incorrectly.

It sounds easy but configuring a muting circuit appropriately. From the instant the first of the two muting sensors is cleared. 29 cfr 1910 217 c 3 iii d the safety distance d s from the sensing field to the point of operation must be greater than the distance determined by the safety distance formula. 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.

The muting circuit for the light curtain must also be appropriately configured for the discrete item s transition speed so that the curtain doesn t remain in a deactivated state. This post will help clarify the difference between the two so the correct safety light curtain functionality is chosen and the machine runs safely. First we test the safety light curtain and latch reset with mute off. In material handling applications material is allowed to pass through the protective field without shutting down the machine.

When enabled a function block is purple with a 3 second count down timer. In normal operation if a light curtain detects an object it causes the safety system to stop any hazardous motion in the hazardous area. Next lets test the mute function. 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. Light curtain with muting two sensor l type and configurable safety relay introduction light curtains are used to detect attempted access to a hazardous area. When a fault in the internal circuitry or an output is detected the light curtain responds by turning off its ossd outputs.