About the UR-81H
General Electric Mutlilin’s UR-81H is a Process Bus Module that provides an eight-port digital process bus to the Universal Relay unit that it is installed in. Unlike most modules, the 81-H is the only Process Bus Module available for the UR series, rather than there being a slew of editions with varying channels and capabilities.
A process bus is a type of communications network that allows the relay to interface with system equipment such as current transformers, circuit breakers, voltage transformers, and disconnectors. The process bus can receive and digitize values recorded by the equipment, allowing users to work with more tangible data on system processes. The transmitted data format is governed by IEC standards that seek to offer a more universal data format for users to parse through.
Users can check if their current system already has this module by examining the model number. Models including “FXX” or “HXX” do not offer the eight-port digital process bus while modules with the “81” do contain the feature already, in which case purchasing this module is ultimately unnecessary.