CAMAC
What is CAMAC?
CAMAC, or Computer Automated Measurement And Control, is a standardized specification that defines electronic modules that are used in nuclear and particle physics. It was first defined by the ESONE Committee in 1972, and was later standardized by the IEEE. CAMAC modules continue to be sold and used today, primarily in national physics and accelerator laboratories.
At the time of this writing (January, 2022) some noteworthy physics laboratories, such as the Fermi National Accelerator Laboratory (Fermilab), make heavy use CAMAC by designing and building custom modules in-house.
A CAMAC module is a vertical assembly 8.7“ (221mm) tall, 0.7” (17mm) wide, and 11.41“ (290mm) deep. Each CAMAC module has a card-edge connector on its rear that carries power and ground lines as well as the CAMAC Dataway, a digital I/O bus. Unlike NIM, the CAMAC Dataway provides digital communication with CAMAC modules, which can thus be accessed and controlled by a bus control module using a protocol and addressing scheme defined in the standard.
CAMAC modules slide into slots in a CAMAC crate, which is a chassis designed to hold CAMAC modules. CAMAC crates include a power supply for their modules, with power provided on the Dataway connectors in the rear of each slot. The most common form factor for crates is 19” rack-mount, though smaller tabletop units are also common. On the rear of a CAMAC crate, the bottom section of each slot is occupied by the Dataway connector, and the remaining space above it is usually open to the outside, for cabling purposes.
The number and types of connectors on the front or rear of a CAMAC module are entirely implementation-specific, i.e. they depend on what function the module is designed to perform.
Typical CAMAC modules are counters, timing pulse generators, amplifiers, digitizers, digital memory (for use with digitizers), pulse-height analyzers for nuclear spectrometry, and many others.
CAMAC modules and crates are, or have been, manufactured by LeCroy, Ortec, BiRa, and many other companies. Due to standardization, CAMAC modules are interoperable between manufacturers, i.e. one can mix LeCroy and Ortec CAMACs in a crate made by BiRa.
At the time of this writing, CAMAC modules and crates are commonly and inexpensively available via various auction venues.