CAMAC is a modular system, consisting of a crate with plug-in modules inserted into slots or stations. The CAMAC crate serves to house the modules as well as to provide a communications dataway between the modules. Connection between the module and CAMAC crate are made with 86 contact points linking each module to the CAMAC dataway. The dataway is a series of parallel wires running along the backplane of the crate such as to link each of the stations, and is more commonly known as the backplane bus. The bus allows for the transmission of digital signals between the modules and crate, and also includes powerlines necessary to operate each module.
All communications along the dataway are controlled by the crate controller (CC). The crate controller always occupies slots 24 and 25 of the CAMAC crate, manages the flow of information on the dataway, and is the only module which can issue commands. Therefore the crate controller is appropriately called the dataway master. All other modules in the crate are slaves to the crate controller. Interfacing of the CC with a computer bus allows access to the crate modules for either control or readout.