TERMINATION FRAME ASSEMBLY WITH PROTECTION FROM EMI FOR FIELD WIRING AND RACK FOR SAME

摘要

A termination frame assembly mounts signal conditioner circuit boards for a data acquisition system individually on a frame with an electromagnetic interference (EMI) barrier extending along the front edge and bending back over the circuit board and then out to form an integral trough through which the field wiring is routed to field terminals on terminal strips in the front face of the barrier. The circuit board is installed from the rear with a guide block, keyed to accept only a selected one of a family of boards, lifting the center of the leading edge to align edge connectors with connectors on the rear of the terminal strips. A plurality of the termination frame assemblies are stacked between, and secured to the front and rear legs of, confronting U-shaped channel members with the field wiring routed vertically along the front legs to the horizontal troughs and with power supply and test signal busses routed along one rear leg and connected by leads to plugs on the termination frame assemblies which engage terminations on the leading edge of the circuit board as it is installed. Additional leads on these plugs are connected to complete a series circuit only when all circuit boards are installed. The stacked termination frame assemblies are mounted in a cabinet with the field terminals and the field wiring in the recessed troughs accessible through a rear door and with the circuit boards which are connected to other equipment in the cabinet by connectors on their trailing edges accessible through the front door.