IPNS Distributed Processing Data Acquisition System

A fast large-area position-sensitive time-of-flight neutron detection system

“…A new FAST Data Acquisition System (FASTDAS) has been developed at IPNS to handle the high instantaneous and time-averaged data rates expected for GLAD. This system is capable of histograming data in a fashion similar to the present microprocessor-based data acquisition systems [5,6] in use for some years on other instruments at IPNS, but can build the histograms at a 300 KHz time-averaged rate. An overview of the system is sketched in Fig.…”

“…This histograming scheme is very similar to that used on the other IPNS instruments, which utilize multiple-microprocessor-based histograming systems. [5,6] Three other features provided by the IPNS multiplemicroprocessor systems have also been built into FASTDAS. Multiple histograming of each event is permitted, so that each event can be binned in several different spectra, each according to its own independent element grouping and TOF format.…”

“…The Multibus, Multibus memory, and microVax-to-Multibus interface are the same type as currently used in the other IPNS data acquisition systems, [5,6] with only switchselectable modifications required to convert between systems. The Multibus has 24 memory address lines which provide an addressing capability of 16 Mbytes (1 "Mbyte" is really 2 2 ® or 1,048,576 bytes).…”