Initial operation and current status of the Fermilab DZero VMEbus-based hardware control and monitor system

摘要

DZero is a large colliding beams detector at Fermilab. The control system for this detector includes twenty-five VMEbus-based 68020 computers interconnected using the IEEE-802.5 Token Ring local area network. In operation, the system will monitor about fifteen thousand analog channels and several thousand digital status bits, interfaced to the 68020 computers by the MIL-1553 multiplexed data bus. In addition, the VMEbus control system uses a memory-mapped multi-VMEbus interconnect to download parameters to more than one hundred VMEbus data crates in the experiment. Remote host computers can then read and set memory in the detector crates over the network by accessing memory in the control crates. This is an extremely useful feature during the construction phase, because low level diagnostics and testing of all the detector electronics can be done over the Token Ring network using either IBM-PC compatible computers or the laboratory-wide VAX system. The VMEbus control system hardware is now being installed in the DZero movable counting house. Installation is expected to be complete later this year. 4 refs., 2 figs.