Utils

Miscellaneous helper tools.

nistreamer.utils.connect_terms(src, dest)

Create a static connection between terminals.

Hint: you can find the list of available terminals and signals as well as permitted routes for each card using NI MAX app. Click the specific card entry in the device tree on the left, then hit the “Device Routes” tab on the bottom of the window.

CAUTION! Static conntections are independent of any NI tasks and will persist until explicily undone, involved cards are reset, or the full system is power-cycled. If left behind, such static connections can lead to physical line double-driving, very confusing sync issues, and even hardware damage.

Parameters:

• src (str) – full source terminal or signal name

• dest (str) – full destination terminal name

Raises:

ValueError – if any terminal name is invalid or if the connection cannot be established.

Examples

>>> connect_terms(src='/Dev1/PFI0', dest='/Dev1/PXI_Trig0')
>>> connect_terms(src='/Dev2/10MHzRefClock', dest='/Dev2/PFI0')

See also

Use disconnect_terms() or reset_dev() to undo static connections.

nistreamer.utils.disconnect_terms(src, dest)

Undo static connection.

Parameters:

• src (str) – full source terminal or signal name

• dest (str) – full destination terminal name

Raises:

ValueError – if any terminal name is invalid.

nistreamer.utils.share_10mhz_ref(dev, term)

Statically export 10 MHz reference clock signal.

CAUTION! Static conntections are independent of any NI tasks and will persist until explicily undone, involved cards are reset, or the full system is power-cycled. If left behind, such static connections can lead to physical line double-driving, very confusing sync issues, and even hardware damage.

Parameters:

• dev (str) – device name

• term (str) – terminal name

Raises:

ValueError – if parameters are invalid

Examples

>>> share_10mhz_ref(dev='Dev1', term='PFI0')

See also

Consider using a safer way of 10 MHz reference export by setting ref_clk_provider() property. This will automatically undo export when run is finished.

If still choosing manual approach, use unshare_10mhz_ref() or reset_dev() to undo this export afterwards.

nistreamer.utils.unshare_10mhz_ref(dev, term)

Undo static export of 10 MHz reference clock signal.

Parameters:

• dev (str) – device name

• term (str) – terminal name

Raises:

ValueError – if parameters are invalid

nistreamer.utils.reset_dev(name)

Perform hardware reset.

Parameters:

name (str) – device name as shown in NI MAX

class nistreamer.utils.RendOption

Enum-like collection of select Plotly renderer options.

See Plotly docs for the full list of available renderers.

browser = 'browser'

notebook = 'notebook'

svg = 'svg'

png = 'png'

jpeg = 'jpeg'

nistreamer.utils.iplot(chan_list, start_time=None, end_time=None, nsamps=1000, renderer='browser', row_height=None)

Plot signals for a list of channels.

Values are computed for a grid of nsamps time points uniformly distributed over the closed interval [start_time, end_time]. Note that sequence has to be freshly compiled to plot.

Parameters:

• chan_list – list of channel proxy instances to plot (trace order will follow the list order)

• start_time (Optional[float]) – window start time. If None, zero time is used

• end_time (Optional[float]) – window end time. If None, compiled sequence end time is used

• nsamps (Optional[int]) – number of time points to evaluate for each channel

• renderer (Optional[str]) – Plotly renderer to use. A few options are collected in RendOption

• row_height (Optional[float]) – channel sub-plot height

Raises:

• ImportError – if plotly is not installed

• ValueError – if sequence is not freshly compiled or any parameters are invalid

Notes

You may need to select a sufficiently large nsamps and a sufficiently narrow time window to see the true waveform shape that the actual stream would produce when sampling at the hardware clock rate. Otherwise, very narrow pulses may be missed and periodic waveforms may appear distorted due to undersampling.