Casio EA-100 Technical Reference - Manual (Page 9)

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Appendix A: Technical Reference
Trigger Edge Edges for Measuring the Time
0 Rising edge to rising edge (T = 0 to 2)
1 Falling edge to falling edge (T = 1 to 3)
2 Rising edge to falling edge (T = 0 to 1)
3 Falling edge to rising edge (T = 1 to 2)
• Frequency measurement cannot be performed correctly whenever 2 or
3 is specified for the trigger edge.
Hard Trigger
The hard trigger is automatically used for period and frequency measure-
ments, and then an external clock signal is being used as the clock. Any one
of seven voltage levels can be selected as the trigger point. The voltage level
is defined by the Command 1 trigger level parameter.
Voltage Level Trigger Level Parameter
–5.0V –10.0 < Vthresh < –2.45
–1.0V –2.45 < Vthresh < –0.35
–0.2V –0.35 < Vthresh < –0.05
0.0V –0.05 < Vthresh < 0.05
0.2V 0.05 < Vthresh < 0.35
1.0V 0.35 < Vthresh < 2.45
5.0V 2.45 < Vthresh < 10.0
Soft Trigger
Soft trigger measurements start at the point the data sampling signal rises or
falls (see the illustration below). The actual point where measurement starts
is defined by the Command 3 trigger edge and clock edge parameters.
0 1 2 3
Trigger Edge Tripper Point
0 HIGH TO LOW (T = 0, 2,...)
1 LOW TO HIGH (T = 1, 3,...)