The SYSCAL Pro Switch units use segments (seg) of multi-core cable which are reversible and interchangeable.
For instance, the SYSCAL Pro Switch 48 with 10m spacing has 4 segments of cable a, b, c, d, with 12 electrodes each, for a total line length of 480m. The SYSCAL is placed in the middle of the line, between segments b and c. If the profile to measure is longer than the line length, a ROLL ALONG technique can be applied where, after a first set of readings with (a, b, c, d), segment a is placed after segment d to form a new (b, c, d, a) combination etc.