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Control System Micro Hardware Configuration

The minimum configuration required for the NSLS micro systems are:

  • a 6U Vme crate
  • a Motorola 680x0 series and Power PC single board computer in the Ethernet controller
  • One megabyte battery backed-up memory
  • GPLS (General Purpose Light Source) board
    (this provides extra timers, serial ports, bus-interrupter module, video display generator, software selectable switches, diagnostic LEDs and a real time clock with 0.1 micro second resolution)

Further hardware requirement for any system is dependent on the hardware equipment under control. Wherever feasible, commercially available boards are used. The hardware I/O interfaces include

  • ADC, DAC and Bit-IO cards in the VME crate
  • RS-232 interface
  • GPIB interface
  • VME to Camac interface
    Using the Kinetic System VME_CAMAC interface board, a single micro can control and monitor instruments within 90 meters distance.
  • Modicon PLC
  • Bus Repeaters
    These are used for different purposes.
    • When all the boards for a system cannot be housed in a single crate, multiple VME crates are used and they are connected to the master crate with bus repeaters.
    • To map a memory segment of one micro into another micro for high data transfer rate.
    • Remote VME crates have been interconnected using bus repeaters with fiber optic cable.
  • Multiple CPUs in one crate. Some micros have two CPUs in one crate. The master CPU interfaces with the workstations and the slave CPU collects data and performs time-consuming calculations. During the software development, the programs are downloaded. The final version is run in PROMs on the board. With the new CPU boards (Motorola 167 or 162), one has the option to boot the final software from the development station when the micro starts up.

For information please contact: Susila Ramamoorthy