The Fermilab ACNET upgrade

Abstract The Fermilab Accelerator Controls Network (ACNET) upgrade consists of a new physical medium (IEEE 802.5 token ring), additions to the calling sequence and added processor support. ACNET is the accelerator control backbone network for all data communication. A proprietary network was replaced by an IEEE standard enabling an open network with excellent characteristics for the control system. The calling sequence was enhanced for the added capabilities of the token-ring interface such as “gather-read” and “scatter-write”. In addition to prior support of DEC PDP11s under RS11M and VAXs under VMS, the ACNET calling sequence was implemented in the language C for the IBM PC with MS-DOS and Motorola 680 x 0 with MTOS using VME bus. Additional support is in progress for Intel 80 x 86 with MTOS using Multibus II.