Embodiments of the invention include a bus bridge that is capable of communicating with more than one MSC device coupled to it. The arrangement of the shelf, sliders, tracks, frame and driving means, which are mounted independently from the frame, enable the shelf to be displaced in relation to the latter. If an irregularity with the putative transaction is detected, the offline balance is adjusted responsive to the detection. The cable-pull and cable-release lever assemblies are operatively connected to the cable spool to rotate the cable spool in the cable-pull and cable-release directions, respectively. During creation of the project definition, a data preview is presented to show how sample data would be affected by the current settings of parameters which affect operation of that module.