Light speed for hazardous areas

Switches with optical fibre ports for zone 1 Industrial Ethernet applications

Ex switch unmanaged ethernet R. STAHL

Introducing series 9721 unmanaged switches with ATEX and IECEx certifications, R. STAHL presents a networking product geared towards process plants with fast Ethernet infrastructure in hazardous areas. Series 9721 switches feature four FX ports for optic fibre cables with type of protection 'op is' (inherently safe optical radiation) according to IEC EN 60079-28:2015, which is akin to electrical type 'i' intrinsic safety. Connected lines can be plugged in and out even in explosive atmospheres in zone 1 and 2 (hot plug). With a shutdown no longer required, changes or extensions to an installation become more cost-effective.

Optical fibre cables are the best and most reliable solution for fast data communication especially in plants with distributed systems, where considerable distances must be bridged or where strong interference may be an issue. The switches themselves can be operated in zone 2, while their fast 100 Mbit/s optical ports connect field devices such as the Ethernet-enabled R. STAHL IS1+ remote I/O system in zone 1.

Depending on requirements, switch types are available for the connection of multi-mode lines that are up to 5 km long, or single-mode fibres up to 30 km long. There is also a mixed solution: one switch type provides one single-mode port to bridge a great distance, while three other devices can be locally connected more cost-efficiently via multi-mode cables. In addition, two electric TX ports with RJ45 jacks are available for connections in non-hazardous areas.

The unmanaged switch type 9721/13-42-x4 can withstand ambient temperatures in a wide range from -30 °C to +70 °C and tolerate the otherwise harsh conditions associated with such extremes. Redundant connection of 24 VDC auxiliary power supply is possible to increase the availability. In addition to IS1+ using Industrial Ethernet protocols such as PROFINET, EtherNet/IP or Modbus TCP, the switches are suitable for HMI devices from R. STAHL HMI Systems and IP cameras from R. STAHL Camera Systems, and obviously also for a diverse range of other field devices requiring type "op is" explosion-protected Ethernet connectivity via optical fibres.


Press contact:


Kerstin Wolf

Am Bahnhof 30
74638 Waldenburg

T +49 7942 943 4300
F +49 7942 943 404300
E [email protected]