Under the black cover, there are eight switches. These switches can be used to simulate fault conditions in various parts of the circuit. The faults are normall used one at a time, but remain safe under any conditions of use. To ensure that the ANACOM 2 board is fully operational, all switches should be set to OFF before use. Access to the switches is by use of the key provided. Insert the key and turn counter-clockwise. To replace the cover, turn the key fully clockwise and then slightly counter-clockwise to release the key.