The principal of the disecq switch is to run multi dishes in to one receiver.

The unit uses pulse's of voltage to change between ports on the switch.

Your receiver will have settings in antenna set up Disecq numbers 1 2 3 4

or in some older receivers ports

A B C D

These are assigned to each dish in your set up

You do not have to use all the ports on the switch eg you can buy a four port switch and only use two ports so you are able to update later