User Manual

196 Chapter 3
Instrument Functions: M - O
Marker Fctn
Instrument Functions: M - O
Remote Command Notes: Using the CALC:MARK[1]|2|3|4:FCO command.
If the specified marker number in the command is not the active marker, it
becomes the active marker. If the marker number is not turned on, it is
first turned on and then it becomes the active marker. Once the marker
count function is turned on, it will be on for any active marker, not just the
marker number specified when the command was sent.
Using the CALC:MARK[1]|2|3|4:FCO:X? query.
The query returns a 1 only if the marker count function is on and the
marker number selected is the currently active marker. The query returns
9e15 if the marker count function is off, or if the specified marker is not the
active marker.
Example: CALC:MARK2:FCO ON
CALC:MARK2:FCO:X? returns the counted frequency.
3.2.5.2 Gate Time
Controls the length of time during which the frequency counter measures the signal
frequency. For 2 ms and longer gate times, the counter resolution is 0.001 Hz. Longer gate
times allow for greater averaging of signals whose frequency is “noisy”, at the expense of
throughput. If the gate time is an integer multiple of the length of a power-line cycle (20
ms for 50 Hz power, 16.67 ms for 60 Hz power), the counter rejects incidental modulation
at the power line rate. The shortest gate time that rejects both 50 and 60 Hz modulation is
100 ms, which is the value chosen when gate time is in
Auto.
Key Path:
Marker Fctn, Marker Count
State Saved: Saved in instrument state.
Factory Preset: Auto, 100 ms
Range: 1 µsto500ms
Remote Command:
:CALCulate:MARKer:FCOunt:GATetime:AUTO OFF|ON|0|1
:CALCulate:MARKer:FCOunt:GATetime:AUTO?
:CALCulate:MARKer:FCOunt:GATetime <time>
:CALCulate:MARKer:FCOunt:GATetime?
Example: CALC:MARK:FCO:GAT:AUTO On
CALC:MARK:FCO:GAT 1e-2 sets the gate time to 10
-2
s=10ms.