DAQSIM - A DATA-ACQUISITION SYSTEM SIMULATION TOOL

At the Superconducting Super Collider Laboratory (SSC) a tool for stud ying the behavior of data acquisition (DAQ) systems has been developed . It is based on the MODSIM II [1] object-oriented discrete-event simu lation language. The tool allows system designers to evaluate alternat ive DAQ architectures in terms of deadtime, throughput and buffer usag e, etc.. The user can specify dynamically the number of chips, the siz e of buffers, the amount of processing time at different stages. as we ll as the bandwidth of the links, etc., for various connection-topolog ies. The type of input data is also user selectable, e.g. fixed-size, GEANT extracted, zero-suppressed, or random according to a number of P robability distributions. DAQSIM has been used to study a network of D ata Collection Circuits (DCC's) in which ''push'' and ''pull'' control strategies have been compared.