4000103-520 | Invensys Cable Assembly

Three triplicated bus systems are etched on the chassis backplane: the TriBus, the I/O bus and the communication bus.The TriBus consists of three independent serial links which operate at 25 megabits per second. The TriBus synchronizes the main processors at the beginning of a scan. Then each main processor sends its data to its upstream and downstream neighbors. The TriBus performs one of two functions with the data:• Transfer of data only—for I/O, diagnostic and communication data.• Comparing data and flagging disagreements— for the previous scan’s output data and memory of user-written control program.Various termination options are available for field wiring of the Tricon chassis, including external termination panels (ETPs) and fanned-out cables. An ETP is an electrically-passive printed circuit board to which field wiring is easily attached. An ETP passes input signals from the field to an input module or passes signals generated by an output module directly to field wiring, thereby permitting removal or replacement of the input or output module without disturbing field wiring.