  In Chinese Spallation Neutron Source (CSNS), proton beam is used to hit metal
tungsten target, and then high flux neutrons are generated for experiments on
instruments. For neutron flux spectrum correction, boron-coated GEM, lithium
glass and 3He are used as neutron beam monitor in instruments. To be integrated
into neutron instrument control, a new DAQ software for neutron beam monitor is
developed, called NEROS (Neutron Event Readout System). NEROS is based on EPICS
V4 and a unified data format for CSNS neutron beam monitor is defined. The
framework and software design of NEROS is introduced in this paper, including
real-time data readout, data processing, data visualization and data storage in
Nexus format. The performance is evaluated through offline test, X-ray test and
252Cf test. The deployment of NEROS and its running result in CSNS instrument
commissioning are also introduced in this paper.
