NIDMM_ATTR_APERTURE_TIME
Specific Attribute
| Data type |
Access | Coercion | High-Level Function |
|---|---|---|---|
| ViReal64 | R/W | Yes | niDMM_GetApertureTimeInfo |
Description
Specifies the measurement aperture time for the current configuration. Aperture time is specified in units set by NIDMM_ATTR_APERTURE_TIME_UNITS. To override the default aperture, set this attribute to the desired aperture time after calling niDMM_ConfigureMeasurementDigits. To return to the default, set this attribute to NIDMM_VAL_APERTURE_TIME_AUTO (-1).
On the NI 4070/4071/4072, the minimum aperture time is 8.89 µs, and the maximum aperture time is 149 s. Any number of powerline cycles (PLCs) within the minimum and maximum ranges is allowed on the NI 4070/4071/4072.
On the NI 4065 the minimum aperture time is 333 µs, and the maximum aperture time is 78.2 s. If setting the number of averages directly, the total measurement time is aperture time X the number of averages, which must be less than 72.8 s. The aperture times allowed are 333 µs, 667 µs, or multiples of 1.11 ms—for example 1.11 ms, 2.22 ms, 3.33 ms, and so on. If you set an aperture time other than 333 µs, 667 µs, or multiples of 1.11 ms, the value will be coerced up to the next supported aperture time.
On the NI 4060, when the powerline frequency is 60 Hz, the PLCs allowed are 1 PLC, 6 PLC, 12 PLC, and 120 PLC. When the powerline frequency is 50 Hz, the PLCs allowed are 1 PLC, 5 PLC, 10 PLC, and 100 PLC.