The AT001 is both an A10 enhanced or standard X-10 based test transmitter. Selection of A10 (6V peak to peak) transmission or X-10 (3V peak to peak) signal output is accomplished with a switch inside the sliding cover on the AT001. A second switch selects the type of transmission used for testing purposes. In the "P1 only" setting the AT001 transmits only the P1 address code without ON or OFF commands. This allows signal verification using an Oscilloscope without turning receivers on and off, disturbing building occupants. The P1 ON/OFF setting sends the standard continuous test pattern of P1 P1, P ON P ON, P1 P1, P OFF P OFF.