An Integrated Data Acquisition System for J-PARC Hadron Experiments

The J-PARC hadron experimental facility has now been completed and is starting operation. We plan to use several types of the readout systems based on CAMAC/FERA, VME bus, TKO, and KEK-VME/COPPER at the early stage of J-PARC hadron experiments. Therefore, we need to integrate many different data acquisition readouts. On the other hand, the network has become the most popular inter-subsystem communication method. Most readout systems have network interfaces or a controller which has network interfaces and talk with the TCP/IP protocol. Under this situation, we have developed network-based DAQ software and trigger/tag distribution system for J-PARC hadron experiments. The DAQ software works with a number of simple function processes and they communicate with each other using two pathways that we call DATA PATH and MESSAGE PATH. The detector data are transported through the DATA PATH and the controllable processes are controlled by the messages via the MESSAGE PATH. The trigger/tag distribution system (TDS) works with three module types, Master Trigger Module, Repeater and Receiver Module. The TDS distributes the timing signals such as the trigger and the event tag using a pair of category six standard network cables. The system works well without any critical issues in bench tests. We will use the system in several J-PARC hadron experiments, such as E05, E13 and other subsequent hadron experiments.