The PXIe-4309 (Part Number: 784471-01) is a flexible resolution Analog Input Module presented by
National Instruments. This module supports up to 32 differential channels. The module multiplexes its
analog input channels across eight simultaneously sampling ADCs. The NI PXIe-4309 can sample eight
input channels up to 2 MS/s/channel. Each channel has an Analog to Digital Converter. This module also
has 32 input channels up to 400 kS/s total (up to 4 channels per ADC). The module’s flexible resolution
ranges from 18 bits at 2 MS/s/channel to 28 bits at 2 S/s/channel.
This module uses a pair of channels to provide high levels of noise rejection and enables accurate and
repeatable Nano-volt measurements. The PXIe-4309 Analog Input Module has two sampling modes:
“averaging” and “single sample”. The sampling mode selection is based on the timing mode. The NI
PXIe-4309 module supports averaging in hardware, which takes a single convert per channel and returns that as a sample.
PXIE-4309
The National Instruments PXIe-4309 Analog Input Module can operate in four timing modes. These
timing modes fall into two groups called “software-timed” and “hardware-timed”. The acquisition rate is
controlled through the software. The software sends a discrete command to the hardware to get each
sample. In NI-DAQmx, software-timed acquisitions are stated as having on-demand timing. Software-timed
acquisitions are also referred to as static acquisitions. These acquisitions are used for reading a single
sample of data. The acquisition rate is controlled through a digital hardware signal (AI Sample Clock). The
NI PXIe-4309 can generate this signal internally. It can also export this signal. Hardware-timed acquisitions
are more efficient over software-timed acquisitions. The time between samples can be much shorter.