When choosing a photoelectric protection device, it is generally used in conjunction with a controller. The controller can enhance the anti electromagnetic interference performance of the light curtain. And it can provide a relatively safer relay output method; At the same time, controllers usually have self checking function, which can effectively improve safety. The controller can also provide other auxiliary functions such as manual reset function, return unprotected function, suppression function, etc.

The controller can generally provide two sets of contact outputs: 1 normally open (1NO) and 1 normally closed (1NC)

Controllers are divided into external controllers and internal controllers according to their installation methods. The external controller is usually a metal shell installed on the machine tool wall; The built-in controller is made of plastic casing and installed in the electrical cabinet.

The relay is the core component of the controller. In order to meet the safety of the system, the manufacturer of the photoelectric protector will use a combination of two or more relays. A controller equipped with only one relay will not be able to be used in the stamping industry or hazardous working environments.