In a typical CODA data acquisition system, one or more UNIX machines are connected via commercial network hardware to multiple intelligent front end crates, for example FASTBUS, CAMAC, PCI and VME. The digitizing hardware is usually in the same crate as the controller but this need not be the case. For example Phobos at RHIC have proposed using dedicated high speed hardware to read out the digitizing hardware, the VME crate then contains only the receiving end of fiber optic links connected to the front end crates. CODA is designed to be very flexible and is inherently modular. This flexibility and modularity make it hard to understand the capabilities of CODA; in fact many features built into the system remain unused. For this reason, in this section we will walk through the CODA system starting at the trigger and working towards the data storage system.
The following sections describe elements from the Figure 2.1 in greater detail.
