Harsh-environment optical bypass relays add reliability for fiber-optic Ethernet networks

From Belden's Hirschmann brand, the OBR40 optical bypass relays protect against network failure when a switch loses power.

Jun 25th, 2013

From its Hirschmann brand, Belden has launched its OBR40 optical bypass relay. Suitable for use in harsh environments, the relays increase the availability of fiber-optic Ethernet networks by ensuring that they remain operational despite power failures at one or more switches.

The bypass relays are designed for both ring and bus topologies. When a switch fails, an internal switchover mechanism in the relay enables data communication to continue seamlessly between neighboring switches. The bypass relay connects to a switch's fiber-optic uplink ports via two duplex inputs/outputs. The mechanism is designed to operate even when the bypass relay loses power.

The unit also supports at-will activation of the bypass function for maintenance or selective shutdown of parts of the network. For example, when the wind gets too strong in a wind park, or when maintenance work is needed, one or more turbines can be easily taken out of the network without affecting the connections of the remainder.

Related: Belden intros annual maintenance for Hirschmann industrial network management software

The bypass relay is available with ports that support three different fiber types (multi-mode 62.5/125 micron, multi-mode 50/125 micron, single-mode 9/125 micron). The switching threshold is adjustable via a DIL switch over a range of 1V to 32V. In addition, a switch-on delay (adjustable for intervals of up to 75s) allows the switch's boot process to complete so that no data packets are lost or delayed when a switch comes back on line.

The relay also features an IP30 protection rating, an operating temperature range of -40°C to +70°C, and a redundant 24 VDC power supply. The 115 x 61 x 113 mm metal housing is DIN-rail mountable. LEDs on the front panel indicate the status of the device and network. “Our new OBR40 optical bypass relays add a new level of reliability for Ethernet networks," comments Belden/Hirschmann product manager Rolf-Dieter Sommer. "[With it deployed] even multiple malfunctions do not impact the network’s overall productivity.”

Related: Unmanaged switches carry Ethernet infrastructure to harsh industrial environments

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