Crate uldaqrs 

Safe Rust bindings for the uldaq library

This crate provides safe, ergonomic bindings to the uldaq library, used for interacting with Measurement Computing / Data Translation DAQ devices (such as the DT9837 series) on Linux.

The unsafe FFI layer lives in the [uldaq-sys] crate; this crate wraps it in a safe API:

• get_device_inventory enumerates the connected devices.
• DaqDevice is a RAII handle to a device: it is created with DaqDevice::create, connected with DaqDevice::connect, and automatically disconnected and released when dropped.
• DaqDevice::daq_in_scan / DaqDevice::a_out_scan start continuous scans into caller-provided f64 buffers, with DaqDevice::daq_in_scan_status / DaqDevice::a_out_scan_status to poll their progress and the corresponding stop functions to end them.

Device setup

Before starting a scan, input channels are typically configured with DaqDevice::set_ai_sensor_sensitivity, DaqDevice::set_ai_coupling_mode and DaqDevice::set_ai_iepe_mode.

Example

use uldaqrs::{
    CouplingMode, DaqDevice, DaqDeviceDescriptor, DaqInChanDescriptor, DaqInScanFlag,
    DaqDeviceInterface, IepeMode, Range, ScanOption, get_device_inventory,
};

// 1. Find a device by name
let devs = get_device_inventory(DaqDeviceInterface::ANY)?;
let desc: DaqDeviceDescriptor = devs
    .iter()
    .find(|d| d.product_name.contains("DT9837"))
    .cloned()
    .ok_or("No DT9837 device found")?;

// 2. Create and connect
let dev = DaqDevice::create(&desc)?;
dev.connect()?;

// 3. Configure the input channels
for ch in 0..4u32 {
    dev.set_ai_sensor_sensitivity(ch, 1.0)?;
    dev.set_ai_coupling_mode(ch, CouplingMode::Ac)?;
    dev.set_ai_iepe_mode(ch, IepeMode::Enabled)?;
}

// 4. Start a continuous scan of 4 channels, 1024 samples per channel
let channels = (0..4)
    .map(|ch| DaqInChanDescriptor::analog_se(ch, Range::Bip1Volts))
    .collect::<Vec<_>>();
let mut data = vec![0.0f64; channels.len() * 1024];
let actual_rate = dev.daq_in_scan(
    &channels,
    1024,
    48000.0,
    ScanOption::CONTINUOUS,
    DaqInScanFlag::DEFAULT,
    &mut data,
)?;

// 5. ... poll dev.daq_in_scan_status() and process `data` ...

dev.daq_in_scan_stop()?;

Prerequisites

This crate requires libusb-1.0 to be installed and is currently only working on Linux systems. Only tested on Linux Mint 22.1 xia.

Install the libusb library and header files with:

sudo apt install libusb-1.0-0-dev

Author information

• J.A. de Jong (Redu-Sone B.V. / ASCEE)

Structs

AOutScanFlag

Flags for ulAOutScan.

DaqDevice

A handle to a DAQ device.

DaqDeviceDescriptor

A descriptor of a DAQ device, as returned by the device inventory.

DaqDeviceInterface

The physical connection interface of a DAQ device.

DaqInChanDescriptor

A single input channel descriptor, used with DaqDevice::daq_in_scan.

DaqInScanFlag

Flags for ulDaqInScan.

ScanOption

Scan options, passed to the scan functions. Bits can be combined.

TransferStatus

Information about the progress of a scan operation.

UlError

A raw error code returned by the uldaq library.

Enums

AiConfigItem

AI configuration items that can be set with DaqDevice::set_ai_config.

AiConfigItemDbl

AI configuration items with a f64 value, set with DaqDevice::set_ai_config_dbl.

CouplingMode

Analog input coupling mode.

DaqInChanType

The type of input channel used with ulDaqInScan.

Error

Errors that can occur when interacting with the uldaq library.

IepeMode

IEPE (constant current) excitation mode.

Range

Analog input / output range.

ScanStatus

The status of a scan operation.

Functions

check

Convert a raw return code from a UL function into a Result.

get_device_inventory

Enumerate the DAQ devices connected to the system that match interface.

Type Aliases

Result

Convenience Result alias for the safe bindings.