Light Curtain Muting Circuit

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.

Light curtain muting circuit.

Safety light curtains reliably and cost effectively protect against access into hazardous points and areas. 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. When enabled a function block is purple with a 3 second count down timer. 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. From the instant the first of the two muting sensors is cleared. In material handling applications material is allowed to pass through the protective field without shutting down the machine. The light curtain s ossd outputs turn on once its field of view is no longer interrupted.

Next lets test the mute function. The range from small and compact types to extremely robust and resistant variants that withstand special ambient conditions up to the highest safety level. Depending on the variant different machine functions are integrated or can be selected via safe control solutions. It sounds easy but configuring a muting circuit appropriately.

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. Muting sensors shall be positioned beyond the light curtain in the dangerous area. The timer monitoring the 4 seconds shall be a safety related item. In normal operation if a light curtain detects an object it causes the safety system to stop any hazardous motion in the hazardous area.

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. The terms muting and blanking are frequently used incorrectly. First we test the safety light curtain and latch reset with mute off. Muting shall be desabled as soon as the light curtain is cleared and not later than 4 seconds max.

If it s muted for too long the curtain will allow access to the safety hazard and obviate its purpose. Also the status output for the mute light changes to green. Muting or bypassing of the psd during the upstroke of the press slide is permitted for parts ejection circuit checking and feeding.