Safety-Interlock System of the DSSC X-Ray Imager

摘要

In this paper, the DSSC safety-interlock system is introduced. It is designedto keep the DSSC mega-pixel camera in a safe-state. The system is composed offour inter-communicating sub-systems referred here as a master SIB(safety-interlock board) and three partner SIBs. Each SIB monitors andprocesses 75 temperature sensors mainly located in the focal plane and alsodistributed inside the camera-head electronics. It monitors the signals fromtwo pressure sensors, one humidity sensor as well as the connectivity tosixteen low-voltage and two high-voltage cables. The master SIB supervises thesignals to and from external equipments like the cooling system, pressuregauge, power crates and status information from experimental environment. SIBis an 8-layer printed-circuit board (PCB) with a micro-controller sitting ontop as its central processing unit. A decision-matrix software reads the sensorstatus continuously and determines whether the camera is in a safe state ornot. All error and warnings flags are sent to the detector control softwareframework and the end user directly. These flags are also stored every 100 mstogether with the image data. The full SIB sensor data is sent to the back endfor offline analysis. A shutdown sequence is initiated by SIB in case of acritical failure. The safety-interlock philosophy, hardware design, andsoftware architecture along with test results will be presented.