Cursor Functions Area

| The cursor area is set up for measurement of data points in the trace, delta measurements and parameteric measurements. Another related function is comparing trace differences by plotting two traces in different colors. The last item is a serial port text box Command Echo that is only visible when Echo On is enabled.

The Sample Point spin edit box is used to set which data point (0 to 255) Collector Voltage VC and Collector Current IC values are displayed. The curve for the data point is the current trace identified by Sweep Step and Trace No. The location of the Sample Point on the plotted trace can be observed by checking Cursor. A small circle will appear on the trace line at the Sample Point.
A reference point can be designated, at the current cursor locaton, by clicking Mark. This data is stored in Ref. V and Ref. I. Delta measurements DV and DI are made with respect to the cursor data and the reference data. The cursor can be on a separate Sample Point or even on a different trace. Both the reference point and cursor sample point are used in calculating trace parameter values.
Comparison between two traces or two parts is useful when trying to identify degradation or damage. Also, it is useful for matching two parts. There are two modes for comparison: to Trace and to Part. The to Trace function uses the plus and minus spin edit buttons to choose the comparison trace. Plus is equivalent to Sweep Step and minus is equivalent to Trace No. to Trace selects the comparison trace from the current part under test. to Part selects the trace from a part stored in a comparison buffer and the trace is the same as selected with Sweep Step and Trace No. Move data from a good know part into the comparison buffer by clicking Swap. This will exchange the compare buffer traces with the displayed part traces.
The comparison trace is plotted in red and the current part trace is plotted in green. The colors are combined on the plot so a matched trace appears yellow.
The list box in the upper right of the cursor area selects the type of parameter to calculate from the trace data. Follow the instructions and click on the parameter in the list box to calculate the value. If the Update With Sweep box is checked, the active list box parameter will recalculate each time a Run Sweep is initiated.

- 0: Resistance: Calculates the absolute resistance slope using the DV and DI delta values.
- 1: Beta: Calculates current gain for a transistor. Mark a data point on a trace with base current A and set the cursor at the same collector voltage point for a trace with base current B.
- 2: Transconductance: Calulates current/voltage gain for FETs. Mark a data point on a trace with base voltage A and set the cursor at the same collector voltage point for a trace with base voltage B.
- 3: Early Voltage: Mark a point on the flat part of a transistor curve then move the cursor to a second point on the flat part of the curve. The program finds the Voltage intercept point at zero current.
- 4: Capacitance: Set the wavefor to a sine or traiangle wave and set sweep to AC Sweep. Capacitance between collector and ground is measured.
- 5: V-Max: Finds the maximum voltage in the displayed trace.
- 6: V-Min: Finds the minumum voltage in the displayed trace.
- 7: I-Max: Finds the maximum current in the displayed trace.
- 8: I-Min: Finds the minumum current in the displayed trace.
- 9: Temperature: Attach a diode between collector (anode) and ground (cathode). Set the sample point somewhere in the forward conduction region. With the diode at room temperature (25C), click Mark. Run Sweep and click Temperature to update the value.
- 10: Zmag Measures the peak-to-peak Voltage and Current then divides voltage by current to obtain the magnitude of the impedance.
- 11: Phase Finds the plus and minus current at the voltage zero crossings. The difference divided by the peak-to-peak current is the sine of the angle. The angle is returned in degrees. Negative angles indicate capacitive reactance while positive angles indicate inductive reactance.
- 12: Zreal Calculates the real part (resistance) of a series impedance.
- 13: Zimag Calculates the imaginary part of a series impedance.
- 14: Series Inductance Caclulates the inductance at 60Hz for a series circuit.
- 15: Ymag is the admittance of a parallel circuit (inverse of impedance)
- 16: Yreal Calculates the real part of admittance or the conductance.
- 17: Zimag Calculates the imaginary part or the susceptance.
- 18: Parallel Capacitance Calculates the capacitance at 60Hz for a parallel circuit.
- 19: Parallel Resistance Calculates the resistance for a parallel circuit.

Pressing the Zero button will zero the lead capacitance or the lead resistance depending of the selected list box item. To clear the Zero value, hold the shift key then click on the Zero button.
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