Safety mat controllers are used to send and receive signals within a hazardous industrial area to make sure that neither workers nor machinery are injured or damaged. Safety mat controllers are connected to either a single safety mat, or a serious of them. These mats, in turn, are lain out in a matrix as a boundary around a machine or robot. When any pressure is applied to a mat, be it from foot traffic or vehicles, conductive plates in the mat touch and signal are sent to the controller via an out put relay. Safety mat controllers then send a stop signal to the machinery surrounded by the mats, making sure that no unfortunate occurrences take place. The time for the signal to travel from the mat to the controller to the machinery is instantaneous.
In addition to reading pressure changes on their connected safety mats, safety mat controllers can also detect short circuits and open circuits. Under either of these conditions, the safety relay sends the stop signal to the machinery. More advanced safety mat controllers may be used to interface with the factory’s industrial system and send a signal notifying about the malfunction.
Safety mat controllers are available in two distinct configurations, box enclosure and DIN-rail. Box enclosure types include a wide variety of controllers that are protected by a metal box. These types may be mounted on walls, pillars, or columns near machinery being supported. Usually these boxes are NEMA rated, as they are located within hazardous areas themselves. DIN-rail safety mat controllers are less cumbersome then their enclosure style brethren. Often, they are mounted further away from the machinery they are connected to. Some safety mat controllers within this class can be mounted into cabinets or racks.
There are two important factors to consider when determining which safety mat controllers will be best for the application at hand. First, what is the maximum number of safety mats that the given controller is able to support. Using safety mat controllers in conjunction with more mats then they are rated for could lead to serious hazardous including misreads and misfires, electrical shorts, and fire. Secondly, how many machines or robots will the controller be connected to? As with the safety mat connections, serious safety issues could occur if the safety mat controllers are used to stop too many machines.