Synchronous acquisition functions

This section describes the synchronous functions implemented in pymanip for signal acquisition on DAQmx and Scope boards. New scripts should preferably use the newer pymanip.aiodaq instead.

DAQmx acquisition module (pymanip.daq.DAQmx)

The fluidlab.daq.daqmx module is a simple functional front-end to the third-party PyDAQmx module. It mainly provides two simple one-liner functions:

The pymanip.daq.DAQmx module is essentially based on its fluidlab counterpart, with other choices for the default values of arguments, and an additionnal autoset feature for the read_analog() function. It also adds a convenience function for printing the list of DAQmx devices, used by the pymanip CLI interface.

A discovery function is also added, print_connected_devices(), based on the dedicated DAQDevice class, which is used by the list_daq sub-command on pymanip command line.

class pymanip.daq.DAQmx.DAQDevice(device_name)[source]

This class is represents a DAQmx device.

Parameters

device_name (str) – name of the DAQmx device, e.g. “Dev1”

It mostly implement a number of property getters, which are wrappers to the PyDAQmx low-level functions.

In addition, it has a static method, list_connected_devices() to discover currently connected devices.

property ai_chans

List of the analog input channels on the device

property ao_chans

List of the analog output channels on the device

property bus_type

Bus type connection to the device

property di_lines

List of digital input lines on the device

property di_ports

List of digital input ports on the device

property do_lines

List of digital output lines on the device

property do_ports

List of digital output ports on the device

static list_connected_devices()[source]

This static method discovers the connected devices.

Returns

connected devices

Return type

list of pymanip.daq.DAQmx.DAQDevice objects

property location

Description of the location (PCI bus and number, or PXI chassis and slot)

property pci_busnum

PCI Bus number

property pci_devnum

PCI Device number

property product_category

Device product category (str)

property product_num

Device product num

property product_type

Device product type

property pxi_chassisnum

PXI Chassis number

property pxi_slotnum

PXI Slot number

pymanip.daq.DAQmx.print_connected_devices()[source]

This function prints the list of connected DAQmx devices.

pymanip.daq.DAQmx.read_analog(resource_names, terminal_config, volt_min=None, volt_max=None, samples_per_chan=1, sample_rate=1, coupling_types='DC', output_filename=None, verbose=True)[source]

This function reads signal from analog input.

Parameters

  • resources_names – names from MAX (Dev1/ai0)

  • terminal_config (str, or list) – “Diff”, “RSE”, “NRSE”

  • volt_min (float, or list, optional) – minimum voltage

  • volt_max (float, or list, optional) – maximum voltage

  • samples_per_chan (int) – Number of samples to be read per channel

  • sample_rate (float) – Clock frequency

  • coupling_type (str, or list) – Coupling of the channels (“DC”, “AC”, “GND”)

  • output_filename (str, optional) – If not None, file to write the acquired data

  • verbose (bool, optional) – Verbosity level. Defaults to True (unlike in Fluidlab)

If the channel range is not specified, a 5.0 seconds samples will first be acquired to determine appropriate channel range (autoset feature).

Scope acquisition module (pymanip.daq.Scope)

This module implements a read_analog() similar to that of the DAQmx module, but for Scope devices. It uses the niScope module from National Instruments.

pymanip.daq.Scope.read_analog(scope_name, channelList='0', volt_range=10.0, samples_per_chan=100, sample_rate=1000.0, coupling_type='DC')[source]

This function reads signal from a digital oscillosope.

Parameters

  • scope_name – name of the NI-Scope device (e.g. ‘Dev3’)

  • channelList (str) – comma-separated string of channel number (e.g. “0”)

  • volt_range (float) – voltage range

  • samples_per_chan (int) – number of samples to read per channel

  • sample_rate (float) – for 5922 60e6/n avec n entre 4 et 1200

  • coupling_type (str) – ‘DC’, ‘AC’, ‘GND’