美国仪器NI 9227 4通道电流输入C系列模块

Simultaneous Sampling

A property of a measurement system in which each input or output channel is digitized or updated at the same instant. You will need simultaneous sampling for applications where the time relationship between inputs is important, such as phase analysis of AC signals.

Because channel-dedicated analog-to-digital converters (ADCs) are used to sample data simultaneously between inputs, the maximum sample rate is applicable to each channel and is not divided by the total number of channels. Devices that don’t have simultaneous sampling capabilities use multiplexing to connect each channel to its ADC.

Interval scanning is a low-cost option to simulate simultaneous sampling for low-frequency signals such as temperature or pressure. This method scans the input channels at one interval and uses a second interval to determine the time before repeating the scan. The input channels are scanned within microseconds, creating the effect of simultaneously sampling the input channels.