Agilent Technologies N4906B Serial BERT User Manual page 104

Setting up the Error Detector
104
The 0/1 Threshold field allows the manual entry of the 0/1 threshold,
and displays the current value in millivolts.
You can adjust the 0/1 threshold in the following ways:
• Click inside the text field and use the numeric keypad or front panel
knob to enter a value.
• Click anywhere in the sampling point display. The sampling point
will be moved to that location.
• Turn the Decision Threshold knob on the front panel. A small
window appears, displaying the threshold value. This knob can be
used at any time, while in any window.
Data Delay
The data input delay defines the point in time (in reference to the
clock signal) at which the incoming data signal is measured.
Specifically, it is the time delay from the active clock edge to the time
at which the data is actually sampled.
This field allows the manual entry of the data input delay, and displays
the current value in picoseconds. This delay can be set as high as 1 bit
period or 10 ns (10,000 ps), whichever is less.
You can adjust the data input delay in the following ways:
• Click inside the text field and use the numeric keypad or front panel
knob to enter a value.
• Click anywhere in the sampling point display. The sampling point
will be moved to that location.
• Turn the Data In Delay knob on the front panel. A small window
will appear, displaying the delay value. This knob can be used at any
time, while in any window.
Clock Falling Edge
Activate this checkbox to move the sampling point from the rising edge
to the falling edge of the clock signal. This function is useful when the
maximum data input delay adjustment is not large enough to move the
sampling point to the desired location. This occurs at very low
frequencies only. See "Bit Rate Range" on page 93 for more
information.
Agilent N4906B Serial BERT, User's Guide, October 2005
Sampling Point Setup