ABB RER103-MM Bus Connection Interface Module

The ABB RER103-MM, also cataloged as the RER103-MM Interface Unit, operates as a dedicated hardware component for optical-to-electrical signal conversion and protocol bridging between localized glass or plastic multi-mode fiber-optic networks and RE500 terminal backplanes.

Hardware Specifications

Industrial Control and Backplane Bus Communications

• Backplane Bus Communication Velocity: The interface module connects directly to the host RE500 sub-assembly via an integrated 9-pin D-type port. This physical alignment allows the transceiver to stream decoded serialization data straight to the core processing unit at up to 1.25 Mbps, matching protective relay polling rates without adding data transmission latency.
• I/O Density Scaling: The protocol converter scales system topology by expanding field network node capabilities without requiring auxiliary input slots. It multiplexes multi-node data streams from complex loop or star fiber paths and fits them cleanly onto a single physical backplane connection address.
• Firmware Flash Compatibility: Internal logic chips govern the physical media translation boundaries for SPA, LON, and IEC 60870-5-103 frames. Field implementation requires that the module's protocol variant mirrors the configuration blocks defined inside the host terminal firmware.

Frequently Asked Questions

Q: How does the RER103-MM manage its 5 VDC power requirements if the host RE500 device experiences a localized brownout?

A: The module does not use an external power input; it derives its 5 VDC operating baseline directly from the internal pins of the host's 9-pin D-type connector. If the host protective relay experiences an internal power drop or brownout, the 5 VDC rail will shut down, causing the RER103-MM optical transceivers to drop out and safely isolating the fiber line logic.

Q: What are the layout consequences when choosing between Loop and Star topologies across the multi-mode fiber optic ports?

A: Ring configurations provide a redundant optical path where a single fiber break will not interrupt communication frames, though it requires setting up an active echo-suppression parameter within the network registers. Star configurations eliminate loop echo considerations but lack media redundancy, making them best suited for short, dedicated point-to-point connections.