Safety touch the edge, and the safety of buffers, are classified into the device of belt. Touch the edge safety, and security buffer, to restrict access, not to say that, but the pressure sensitive feeling. Safe edge as well as the safety buffer, completely by feeling, pressure sensitive, and transmitted to the switch signal, the security protection. Therefore, on the edge of the safety related control circuit is very important, in general, these security on the edge of the use, can only be used in some power once stop, campaign to stop the related machine, to ensure personal safety.