VXI INTERFACE

The NEFF 500022 is a C-size, register-based VXIbus module that provides an interface between the VXIbus and various front-end products. Two identical controller devices are included on the module to support two NEFF systems. Supported systems include the Series 600, System 470, 471 472 and Series 300.

The 500022 module provides dual port memory to store channel scan lists which may be updated on the fly. Up to four individual scan lists may be stored in the scan list memory buffer and each list is assigned an individual scan clock rate. Each scan list may be an input list or an output list.

Input scan lists contain channel addresses and full scale gain step codes.

Acquisition scan clocks are derived from the 10MHz VXIbus clock signal ensuring that multiple front end systems sample data points and receive output data synchronously.

Error detecting logic is employed to flag various conditions which may occur while data acquisition tasks are running. Three error conditions are monitored: Slipped Scan, Scan Overrun and Stagnant Data.

The 500022 Controller provides a multiple scan list capability which permits channels within the same system to be sampled at different rates. This approach allows multiple scan rates using only one I/O port.

Multiple front-end systems may be connected to separate I/O ports on a single controller and run concurrently. Multiple controllers may be installed in a single VXI crate.

Neff Instruments, 700 South Myrtle Avenue, Monrovia, CA 91016. Tel: 626-3572281; Fax: 626-303-2286.