Control of the Subaru telescope instrument exchanger system

The CIAX system especially CIAX-3 increased observation efficiency for Cassegrain test instruments at the early phase of Subaru telescope test observation. In order to control this system effectively and automatically, a control software for the entire system of the CIAX was developed. The software design goals are (1) redundancy for robust system, (2) the safety of the instrument by interlocking, (3) maximum efficiency by automatic control and (4) easy user interface for operator. In this paper, we describe the software which has been being tested through the telescope and instrument commissioning phase.