Distributed Signal Multiplexor at Fermilab

Charles Briegel
Fermi National Accelerator Laboratory


A set of 1 GHz multiplexors are distributed at remote locations which enable signals to be routed to a variety of instrumentation equipment. The commercial multiplexor provides up to 20 1X4 switches per location and can be controlled via GPIB.

Control of the multiplexors utilizes MOOC (Minimal Object Oriented Communications) which provides the skeleton software for communication to an application program. The control of a route across distributed multiplexors can be effected by turning "ON" a device. The route has various mechanisms for reserving or acquiring the ownership of the muxes which make up the signal's route. The aplication and front-end software implementation is described.

The hardware consists of a VME crate, a 68040 processor running vxWorks operating system, and GPIB interfaces including transparent support of a remote GPIB connected via Ethernet to the front-end computer.