Cost-optimized Systems For Protecting Complex Machines And Systems

The series connection significantly reduces the wiring effort. A particular advantage of these installation systems is that different electronic safety switching devices such as sensors and tumblers can be mixed in the respective application. Because in larger systems, different machine areas often have to be protected with different safety switches. The new system also offers cost-optimized variants for applications with only electronic safety switching devices.

Individual diagnosis of connected devices possible

With the safety installation systems, individual diagnosis of the connected safety switching devices is also possible. This means that the operator can clearly see which switch in the row has triggered a signal. In this way, malfunctions can be eliminated more quickly and machine downtimes avoided. The safety installation systems from Schmersal thus contribute to increasing machine availability.

Variants with a passive distribution module (PDM) or a passive field box (PFB) are available for applications with only electronic safety switching devices. They enable mixed series connection with up to four different electronic safety switching devices per module. Several modules can be interconnected to form larger systems:

• The passive PDM distribution module is small and compact, can be easily installed in existing terminal boxes and is particularly suitable for the increased hygiene requirements for food and packaging machines
• The passive field box PFB is a plug & play solution in a robust IP67 version for a wide range of applications. Larger systems can be wired with the PDM and the PFB because wire cross-sections of up to 1.5 mm² can be connected. A unique feature of these two solutions is the individual protection of the safety switching devices by means of line protection with a self-resetting fuse.
• There is a third and active variant for safety switches and safety sensors: In the safe series connection of electromechanical safety switches with contact outputs or of safety sensors with electronic OSSD outputs, a safety input extension of the SRB-E series takes over the active electronic signal evaluation. With this solution, a safety level of Cat. 4 / PL e / SIL 3 is also achieved with the series connection of contacts.

Optional transmission of non-secure data

The passive installation systems can also optionally be equipped with a "serial diagnosis" (SD) interface for the transmission of non-secure data. Safety sensors and tumblers in the series connection that are equipped with an SD interface can be used to transmit and visualize extensive diagnostic data to a controller via the SD gateway and a fieldbus.

With the MZM100-SD non-contact magnetic safety locking device, this can be, for example, diagnostic data or error messages, such as "error or cross-circuit at a safety output", "operating voltage too low" or "defective actuator". This enables quick troubleshooting. In the future, extended diagnostic functions will also enable predictive maintenance and avoid machine downtimes. (jv)