ExaPen User Manual - 1. Voltage meter

1.1 Voltage meter

The voltage menu has 4 indicators:

1. State of the ⬤ button
2. 1kOm resistor indicator
3. Supply voltage
4. Voltage on the probe tip

Operation

To measure the voltage connect the probe tip to a tested circuit. 

The long press of the ⬤ button will enable internal pull-down through the 1 kOm resistor. This feature is useful for distinguishing the power and signal lines of sensors with internal pull-ups in the ECU. The voltage reading on the power line will not drop when the pull-down resistance is applied. Meanwhile, the voltage reading on the signal line will drop around 25% regarding the initial state. 
The Voltage meter automatically detects VCC and GND lines. The detection is indicated by an integrated dual-color LED and buzzer with different tones for both lines (if enabled in the settings). Green LED represents the GND line, and the Red LED represents the line with VCC +/- 10% voltage. 

1.2 Voltage meter with automatic pull-down.

In this option, 1 kOm resistance is automatically applied. Indicator 1 will show the state of the tester’s circuit. More useful to check sensor wirings but may drop some weak signals. 

The Voltage meter automatically detects VCC and GND lines. The detection is indicated by an integrated dual-color LED and buzzer with different tones for both lines (if enabled in the settings). Green LED represents the GND line, and the Red LED represents the line with VCC +/- 10% voltage. 

1.3  Signal plotter

The plotter menu has 5 indicators:

1. Voltage on the probe tip
2. Max registered voltage on the current plotter screen
3. Min registered voltage on the current plotter screen
4. Buzzer state (on/off)
5. Signal line

The signal plotter shows a real-time signal curve. The resolution can be set in the next submenu.

Operation

    ExaPen monitors the input signal in a real-time and shows the signal shape on the screen. 
Using voltage monitor:

1. Connect the probe tip to the tested line
2. The long press of the ⬤ button. ExaPen will save the value, which will be monitored in further readings.

3. A single press of the  ⬤  button will proceed with the plotter operation
4. Once the current voltage reading goes +-5% from the stored voltage - the buzzer will be activated to indicate the voltage rise or drop. 

Voltage monitor feature is useful for testing bad wirings and voltage drops on heavy loads.

1.4 Voltage meter settings

This submenu allows you to choose the plot type (line or graph), enable or disable acoustic indication for the voltage meter and the plotter voltage monitor, and change the scale of the plotter window.

Operation

1. Navigate using ◀ or ► buttons to the settings menu.

2. Single press the ⬤ button to activate item edit.   The sign “⪡” will indicate the item you will edit. A single press will move the sign.

3. Use ◀ or ► to change the item.

4. Press the button ⬤ until the editing sign disappears. 

5. Navigate using ◀ or ► to the desired voltage meter or voltage plotter function. 

The plotter scale setting to 1s allows to detection of CAN-Lo and CAN-Hi signals in the plotter. This function is beta-testing.