User`s guide

53220A/53230A User’s Guide 171
Triggering and Gating 5
External Gate Signal Polarity
When using an external gate source, the polarity of the gate signal is changed
with the command:
[SENSe:]TINTerval:GATE:POLarity {POSitive|NEGative}
[SENSe:]TINterval:GATE:POLarity? (query form)
POSitive enables a time interval measurement following a positive edge on
the Gate In/Out BNC. NEGative enables a time interval measurement follow-
ing a negative edge on the Gate In/Out BNC. For either edge, the measurement
begins on the first start event after the (gate) edge.
Following a reset (*RST) or instrument preset (SYSTem:PRESet or Preset
key), the negative edge (polarity) is selected.
Gate Source ADVanced
Gate source ADVanced enables extended control of the gate signal through the
counter’s SENSe:GATE commands (see Advanced Gate Control later in this
chapter).
The following example shows configuration of a time interval measurement
beginning with high-level configuration of the counter, setting up the start and
stop events, and changing the polarity and gate source.
//configure the counter for a time interval measurement
//using external gating to start the measurement