Please excuse my ignorance....but biu...is that similar to an inductance (impedance??) loop detector under ACP? I am familiar with how to test those detectors, but am unfamiliar with the term BIU. KRS Services
The BIU (Bus Interface Unit) is a key component in a modern NEMA TS2 signal cabinet.The BIU is responsible for converting all the (formerly hardwired) inputs and outputs that need to be monitored by the controller into reliable, high-speed data packets. The only link between the BIU and the controller unit is the SDLC bus, which makes testing of individual
BIUs extremely difficult outside of a fully functional TS2 cabinet. Even then, only cursory testing is possible because built-in TS2 controller diagnostic capabilities are
extremely limited. So how are you testing?
