The distance of the control cable is limited by the distance the network analyzer or monitoring device can be from the device. There are two connections between the switch and the analyzer - the Control cable, which connects to the COM port for Serial Control purposes, and the Common cable, which provides a data connection to the monitor card for the topology being analyzed. The total cabling distance is determined by calculating the total length of all cables (the primary cables, daisy chain cables and any additional cables between the matrixes switch Network ports and the data access points such as SPAN ports). When all relevant cable lengths are added together the sum must be equal to or less than the maximum allowable distance for the topology in use (e.g. the Common cables, Daisy cables and cables from 4X16SP-1000BT to SPAN port must not exceed 100 meters).