The setups for precise measurements of the time structure of Nuclotron internal and slowly extracted beams are described in both hardware and software aspects. The CAMAC hardware is based on the use of the standard CAMAC modules developed and manufac
tured at JINR. The data acquisition system software is implemented using the ngdp framework under the Unix-like operating system (OS) FreeBSD to allow the easy network distribution of the online data. It is demonstrated that the described setups are suitable for the continuous beam quality monitoring during the experiments performed at Nuclotron.
The ngdp framework advanced topics are described. Namely we consider work with CAMAC hardware, selfflow nodes for the data acquisition systems with the As-Soon-As-Possible policy, ng_mm(4) as alternative to ng_socket(4), the control subsystem, user c
ontext utilities, events representation for the ROOT package, test and debug nodes, possible advancements for netgraph(4), etc. It is shown that the {itshape ngdp} is suitable for building lightweight DAQ systems to handle CAMAC. The investigation has been performed at the Veksler and Baldin Laboratory of High Energy Physics, JINR.
The ngdp framework is intended to provide a base for the data acquisition (DAQ) system software. The ngdps design key features are: high modularity and scalability; usage of the kernel context (particularly kernel threads) of the operating systems (O
S), which allows to avoid preemptive scheduling and unnecessary memory--to--memory copying between contexts; elimination of intermediate data storages on the media slower than the operating memory like hard disks, etc. The ngdp, having the above properties, is suitable to organize and manage data transportation and processing for needs of essentially distributed DAQ systems. The investigation has been performed at the Veksler and Baldin Laboratory of High Energy Physics, JINR.
