VXI VT1538A user manual Init, Send with VXIplug&play Function hpe14XXcmd

exceeds the time-out period (i.e. frequency below LIMit:LOWer), then a frequency of 0 Hz will be returned to the E1415/19/22 algorithm.

•Typical use for this command is to allow the user to bound the period of time that is allowed for making a frequency measurement, thus, preventing the SCP from “hanging” during measurement.

In this case, typically, the LIMit:LOWer frequency would be the same as, or slower than the frequency associated w/the APERture time.

•An unusual (but valid) use is to set the LIMit:LOWer frequency to be greater than the frequency associated with the APERture period, which can provide a means to abort a frequency measurement if at any point during the measurement, the input waveform frequency is slower than the configured LIMit:LOWer frequency.

Note The lower limit set by SENS:FREQ:LIM:LOW is for a single signal period, not the sum of NPERiods. Unless at least one period of the input signal exceeds the limit value set, then NPERiods will be measured and averaged to return a reading. For instance if;

SENS:FREQ:MODE NPERiods,<ch_list> SENS:FREQ:NPERiods 255 SENS:FREQ:LIMit:LOWer 0.01667 ! 60 second period

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INIT

As long as the input signal frequency is slightly greater than the LIMit:LOWer frequency, then the SCP will not time-out and will take 255 * (~60sec) = ~255 minutes to take a single frequency measurement.

Alternatively, if even one of the input waveforms has a frequency that is lower than the LIMit:LOWer frequency, then 0 Hz would be immediately returned to the E1415/19/22 algorithm.

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Related Commands: SENS:FREQ:APER, SENS:FREQ:LOW?

*RST Condition: is “MINimum” frequency (i.e. 0.01667 Hz [period = 60sec]).

Send with VXIplug&play Function: hpe14XX_cmd(...)

Agilent E1538A Enhanced Frequency/Totalize/PWM SCP 49