VXI VT1538A user manual Send with VXIplug&play Function hpe14XXcmd

the LIMit:UPPer period, then a period of 0 sec will be returned to the E1415/19/22 algorithm.

(Note: A period value of 0 sec is used as a special token that must be tested for in the user’s provided 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 period measurement, thus, preventing the SCP from “hanging” during measurement. In this case, typically, the upper period limit would be the same as, or longer than the APERture time.

•An unusual (but valid) use is to set the LIMit:UPPer period to be less than the APERture period, which can provide a means to abort a period measurement if at any point during the measurement, the input waveform period is longer than the configured LIMit:UPPer.

Note The upper limit set by SENS:PER:LIM:UPPer 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:PER:MODE NPERiods,<ch_list> SENS:PER:NPERiods 255 SENS:PER:LIMit:UPPer 60

...

INIT

When the input waveform period is slightly less than the upper period limit, then the SCP will not time-out and will take

255 * (~60sec) = ~255 minutes to take a single period measurement.

Alternatively, if even one of the input waveforms has a period that exceeds the LIMit:UPPer period, then 0 sec would be immediately returned to the E1415/19/22 algorithm.

•*RST Condition: is “MAXimum” (i.e. 60.0sec).

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

58 Agilent E1538A Enhanced Frequency/Totalize/PWM SCP