Unmanaged switches protect industrial Ethernet applications
Unmanaged switches with ATEX and IECEx certifications, the series 9721, are designed for use in plants with fast Ethernet infrastructure in hazardous areas.
They feature four FX ports for optical fibre cables with inherently safe optical radiation protection, according to IEC EN 60079-28:2015; this is akin to electrical type ‘i’ intrinsic safety, says the company. Connected lines can be plugged in and out even in explosive atmospheres in zone 1 and 2 (hot plugging). With a shutdown no longer required, changes or extensions to an installation become more cost-effective, claims the company. Optical fibre cables are reliable 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 can be operated in zone 2, while the 100Mbit/s optical ports connect field devices such as R Stahl’s Ethernet-enabled IS1+ remote I/O system in zone 1.
Types are available for the connection of multi-mode lines that are up to 5.0km long, or single-mode fibres up to 30km long. A mixed solution is one switch type providing one single-mode port to bridge a large distance, and three other devices locally connected more cost-efficiently via multi-mode cables. 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 from -30 to +70 degree C and tolerate the otherwise harsh conditions associated with such extremes. Redundant connection of 24V DC auxiliary power supply increases 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 the company’s HMI systems and IP cameras, as well as field devices requiring inherently safe operation for explosion-protected Ethernet connectivity via optical fibres.