An oscilliscope can be hooked up to Pilot (blue) and Ground (green) leads in the front of the tester for measurements.
The Selector switch will show State A, State B, State C and State D of the EVSE so that you can see that it conforms to the J1772 Standard.
Diode switch should be in On position and can be switched to OFF anytime to test
State A – OFF – LCD will show Hz , Duty Cycle and A with no value and no value on V/A meter since no input.
State B – Connected Duty Cycle – Ampacity, LCD will show Hz, Duty Cycle and A of your EVSE.
Duty cycle % and A shown on LCD should correspond to Duty Cycle chart on label. This is info only and there is no current/amps showing.
State C – Charging AC On, you should hear the contactor in your EVSE ‘clunk’ closed. If your EVSE uses relays, you might be able to hear the relay click closed.
Hz, Duty cycle and A will show on LCD, Volts will show on V/A meter and A will ramp up and settle back to 0 because there is no load (J1772 Tester Plug is not plugged in to load).
State D – Venting Request – and the EVSE will probably fault out. This part of the J1772 Spec is a left over state fromlead acid batteries on the first go around of EV’s and J1772 Spec
(every one of the EVSE’s that I have tested have faulted out at this state)
To see A meter working, you need to use your EV as a load. The EV and EVSE will handshake and charge the EV, you can monitor the signals using the pilot and ground leads.