Development of the spectrograph control software package for SDSS-Ⅴ Local Volume Mapper Instrument

The Local Volume Mapper (LVM) project among the fifth iteration of the Sloan Digital Sky Survey (SDSS-V) plans to produce large integral-field spectroscopic survey data. The data will reveal the physical conditions of the interstellar medium in the Milky Way, the Magellanic Clouds, and other local-volume galaxies. We developed the Local Volume Mapper Spectrograph Control Package (LVMSCP) which controls the spectrograph subsystem. The architecture design of the software based on Python 3.9 follows a hierarchical structure composed of high-level, mid-level, low-level software packages, and hardware components. We used the new SDSS message passing protocol CLU for the interaction, based on RabbitMQ that implemented the Advanced Message Queuing Protocol (AMQP). The Actors that receive or produce messages to each other are also the units of the conceptual operation. Furthermore, the package applies asynchronous programming with non-blocking procedures since the three spectrographs should operate simultaneously. For requirement of the incremental code change and management in the collaboration of the developers, we adopted the SDSS Github Action which supports Continuous Integration (CI) / Continuous Deployment (CD). As a part of this, Unit testing with Pytest tests the individual components of a software respectively. Finally, the LVMSCP provides the Application Programming Interface (API) to the Robotic Observation Package (ROP) for the integrated observation to fulfill the required scientific survey execution for the spectrographs.