CONFigure:COUNter:FREQuency
Syntax
CONFigure:COUNter:FREQuency [{<gate_time>|MIN|MAX|DEF},] (@<ch_list>)
Description
This command configures the specified counter channels on the 34950A Digital I/O Module to measure the frequency of the incoming signal. For frequency measurements, you must send the [SENSe:]COUNter:INITiate command to initiate the measurement. The specified gate time is the measurement aperture during which the signal data is gathered. For repetitive signals, longer gate times will lead to increased resolution for frequency, period, pulse width, and duty cycle measurements.
The CONFigure command sets the counter parameters to their default values as shown below.
|
Parameter |
CONFigure Settings |
|
Slope |
POSitive (rising edge) |
|
Input Threshold Voltage |
2.5V |
|
Gate Source |
INTernal |
|
Gate Polarity |
NORMal (active high) |
Used With:
34950A Digital I/O Module
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<gate_time> |
Numeric |
Desired gate time between 100 ns and 10 seconds, with 50 ns resolution. MIN = 100 ns, MAX = 100 seconds |
1 ms |
|
<ch_list> |
Numeric |
One or more counter channels in the form (@sccc).
|
This is a required parameter |
Remarks
The frequency is measured as: (NumberRisingEdges
– 1)/GateTime. The specified counter channels must detect at least two edges for a valid frequency measurement. The maximum input frequency allowed is 10 MHz.
To read the frequency, use the [SENSe:]COUNter:DATA? or [SENSe:]COUNter:FREQuency[:DATA]? command.
Sending the CONFigure command clears reading memory and resets the triggering system.
Example
The following command configures counter channels 301 and 302 on the module in slot 3 to measure frequency. The gate time is set to 1 ms.
CONF:COUN:FREQ
1E-3,(@3301,3302)
COUN:INIT (@3301,3302)
COUN:FREQ? (@3301,3302)
Typical Response: +3.45600000E+05,+3.31300000E+05