In the early versions of CODA the system was configured using text files. This was nice since no special configuration tools were required but rapidly became hard to manage when the number of readout controllers and other processes became large. For this, and other, reasons CODA 2 uses a relational database to store configuration information. For reasons of size, cost and speed the msql database software was chosen and integrated into CODA. Unfortunately it is difficult (impossible?) to replace msql with a different database. This issue is being addressed in the next production release of CODA. Since a relational database is not as intuitive to the user as flat files we provide two tools to access the database. The cedit tool is used to generate run configurations. It is a layout editor where the user draws a diagram of the daq system complete with data paths. As each component is added to the diagram, cedit prompts the user for additional information such as the location of readout lists and the event format. The cedit tool covers most of the standard configurable parameters found in CODA. Sometimes it is necessary to directly interact with the database. The dbedit tool provides this functionality. It allows the user to display and modify tables in the database directly. This is a dangerous tool and should be used with care since no checks are made on the format of the data entered in the database. It is assumed that the user of dbedit is familiar with the format of the database tables and the correct parameters values.
The main run control portion of the CODA takes the form of two programs. A client control engine performs monitoring and control of the system via an internal model of the daq system. The control engine constantly compares its internal model of what should be happening in the system with the real system and warns the user of any inconsistencies. The second half of the run control system is the user interface. This program provides the user with information about the current status of data taking and allows the user to control the system. CODA runs are configured using two programs cedit and dbedit which are used to manipulate a relational database (msql). The run control user interface allows selection of predefined run configurations. Both of the configuration editors can be docked in the main user interface so that all three programs appear to behave as one coherent interface. In the case of cedit the diagram of the daq system becomes active when docked in the run control user interface. Labels on each component indicate its state, as perceived by the run control engine, and change color as the components change state. There are many other features of the run control system which are discussed in detail in this manual.