Input expanders

ENTRANCE EXTENSIONS

To ensure the safety of machines and systems, movable guards such as doors or flaps are monitored with safety sensors or solenoid interlocks. To avoid having to wire these individually in the control cabinet, interfaces or input expansions are used in which the safety switching devices are connected in series and connected to the safety evaluation unit via a single cable. Schmersal's solutions for the cost-effective wiring of safety switching devices in a series connection are divided into passive distribution modules and field boxes for the connection of electronic safety switching devices and active input extensions - the SRB-E multifunctional safety relay modules - for the connection of safety switches and safety sensors with contact outputs or in an electronic version.

PASSIVE DISTRIBUTION MODULES AND FIELD BOXES

The passive PDM distributor modules and passive PFB fieldboxes for installation in switching cabinets or terminal boxes and the fieldboxes for field wiring are suitable for series wiring of electronic safety switchgear, such as sensors and interlocks. With the passive installation systems it is possible to realise mixed series connection of electronic safety sensors and interlocks from Schmersal. The distributors and field boxes are available in different versions for parallel IO wiring and for wiring to the Schmersal SD interface.

ACTIVE INPUT EXTENSIONS

The SRB-E-204ST and SRB-E-204PE active input expander modules are used for safe series connection of switches and sensors to contact outputs or electronic OSSD outputs. Within the active input expander modules, the individual switch contacts or OSSD outputs are reliably evaluated by an electronic system and as a series circuit safely AND-linked. The SRB-E safety relay modules are intended for installation in switching cabinets and achieve category 4/PL e/SIL 3 safety level. In addition, Schmersal will continue to offer PROTECT series input expander modules until the end of 2024.