Abstract: A switching matrix arrangement using magnetic latching reed relays is disclosed, wherein similarly numbered switch groups and verticals are connected in common and are driven simultaneously with the exception of a grid select signal which is unique to a particular grid. Further as a check on the operation of the grid various sensors are located throughout the network to monitor the selector. Because of the multiple connections leakage current which flows from the unselected groups may cause operation of unselected group monitor sensors. To prevent this a combination sensor and current sink is used that shunts the leakage currents around the sensor.