  Very compact 70 MeV pulse race-track microtron is under construction now. To
acquire outputs of beam-current transformers on every orbit and pulses of high
voltage and RF field a distributed multi-channel beam diagnostic system was
developed. Each acquisition controller consists of four fast differential
amplifiers and one DSP-based micro-controller with on-chip ADC and CAN-bus
controller. Each amplifier is coupled with beam-current transformer and has
bandwidth of up to 150MHz and gain of up to 10. One of four channels is
acquired during a measurement cycle. Another channel could be selected between
two following pulses. All the controllers are connected via optically coupled
CAN-bus with a host diskless PC running under Linux with the RTLinux extension.
Dedicated software of the system consists of low level acquisition software for
DSP, network software for controllers and host PC, application software for PC
to present date for operator and control system. Standard CAN application
layers were considered but refused because of the closed character of the whole
system and centralised synchronisation of the whole system. Dedicated software
of the system consists from low level acquisition software for DSP, network
software for controllers and host PC, application software for PC to present
date for operator and control system. Standard CAN application layers were
considered but refused because of closed character of the whole system and
centralised synchronisation of the whole system.

Accelerator Physics