Envision Peripherals NV3128 Circuit Operation, 4.2.1 I/O CONNECTOR INTERFACE, Signal Backplane

4.2 CIRCUIT OPERATION

The following discussion provides an overview of circuit operation for each of the circuit boards in the NV3128 Router frame. Because repair is done by replacing modules rather than repairing them, schematics and bills of material are not provided but may be requested from NVISION Technical Support.

4.2.1 I/O CONNECTOR INTERFACE

ASSY: EM0038-XX

RS-422A Machine Control data enters the NV3128 through PC- mounted D connectors on this passive connector interface assembly. On each D connector, an RC circuit AC couples the input shield terminal to ground. High density Metral connectors route the signals back to the active I/O and Command Interpreter Modules.

A bayonet style BNC connector receives the reference video input and loops it through to a second to facilitate daisy chain connections. Alarms and changeover connections arrive via Phoenix terminal blocks. Two spare BNCs are provided to accomodate possible future customization.

D connector sets carry command information from the external router control system, the diagnostic interface, and (on older frames) the parallel interface. The RS-232 and RS-422 interfaces are 9-pin D connectors, and the parallel interface is a 37-pin D. The primary control and parallel connectors have neighboring connectors that can be used for loop through. Note that the primary ports and their loop- thru connectors are not equivalent; you must connect the control system directly to the primary port.

4.2.2 SIGNAL BACKPLANE:

ASSY: 0039-XX

This captive, passive assembly mounts the high-density Metral connectors that carry the intra-frame signal traffic.

NV3128 RS-422A Machine-Control Data Routing Switch 4-5