The steady state operation of Wendelstein 7-X stellarator presently under construction in Greifswald poses special challenges to the diagnostics development [1, 2]. A critical issue is the heat load on plasma facing components (∼500 kW/m2) over a long discharge time (up to 30 min), which leads to the necessity of active cooling. As result, the design of the 400 channel soft X-Ray Multi Camera Tomography System (XMCTS) [2, 3] has to cope with dark currents and amplifier drifts due to the heating of active components like photo diodes and in-vessel preamplifiers. In order to allow for a quantitative measurement of dynamic drifts and offsets, a shutter system and blind diodes are considered to compensate these effects. Another important issue is the large amount of data gathered by the XMCT system during long pulse discharges. A fast but less precise online reconstruction is planned, which will give information on the plasma shape and position on a human time scale. The two options under investigation are a ...