GeneriCAN: CAN Node Design for CARMA

James Lamb, Jim Fredsti, and Brad Wiitala
Owens Valley Radio Observatory, California Institute of Technology

Abstract

We present the basic design of hardware and software for a generic
CAN node based on the experience at OVRO. The intention is not to
present a single CAN node design to perform all functions, but rather
to provide a template from which to develop hardware and software for
specific applications. A certain minimum hardware functionality is
provided, with a prescription for adding new capabilities. A kernel
of software will be provided to implement core capability such as
scheduling of tasks in a time-critical manner, driver software for
various types of devices, and templates on which new projects can
be based.

Many CARMA-specific requirements are already implemented. These
include: precision timing and time stamps; a CAN connector definition
that includes Reset, Timing, and Power lines; a CAN address format
standard; and fast and slow monitor package handling.

Numerous different CAN nodes will be required for CARMA so it is
important to maintain reliable control of code and documentation. No
specific procedures are currently implemented, but these must be
implemented as a CARMA-wide solution.