Cards#

Card module.

Contains the BaseCardProxy and AO/DOCardProxy classes representing individual cards.

class nistreamer.card.BaseCardProxy(_streamer, max_name, nickname=None)[source]#

Bases: object

The base of card proxy classes.

Exposes hardware settings and device-wide control.

property nickname: str#

Human-readable card name used in visualizations.

Nickname is set when card is added to the streamer. If no nickname was specified, card MAX name is used instead.

property samp_rate: float#

Sampling rate (in Hz).

property start_trig_in: str | None#

Start trigger input.

Format:

  • term: str - card awaits for an external start trigger at terminal term;

  • None - card does not use external start trigger.

property start_trig_out: str | None#

Start trigger output.

If configured, the card will emit a pulse every time it starts running. This signal can be used by other cards to start-sync.

Format:

  • term: str - emit signal at terminal term;

  • None - no export.

property samp_clk_in: str | None#

Sample clock input.

Format:

  • term: str - card uses external sample clock from terminal term;

  • None - card uses internal on-board sample clock instead.

property samp_clk_out: str | None#

Sample clock output.

Format:

  • term: str - card exports sample clock to terminal term;

  • None - no export.

property ref_clk_in: str | None#

10 MHz reference clock input.

Format:

  • term: str - on-board clock locks to the reference signal from terminal term;

  • None - on-board clock is free-running.

See also

Use ref_clk_provider() to specify which card provides the reference signal for others.

property min_bufwrite_timeout: float | None#

Minimal buffer write timeout (in seconds).

The main purpose - deadlock prevention when hardware sync fails and some cards either never start or get stuck midway (typically, due to incorrect / missing start trigger or external sample clock). Streamer will stop and return a RuntimeError if timeout elapses.

Format:

  • val: f64 - finite, wait time of at least val seconds;

  • None - no timeout, wait indefinitely.

The default is 5 seconds. A larger value can be set to allow a longer wait for an external signal or if external sample clock “freezing” is used to “pause” generation for periods of time.

clear_edit_cache()[source]#

Discards all instructions from channels on this card.

reset()[source]#

Performs hardware reset

last_instr_end_time()[source]#

Returns the last instruction end time or None if the edit cache is empty.

Return type:

Optional[float]

class nistreamer.card.AOCardProxy(_streamer, max_name, nickname=None)[source]#

Bases: BaseCardProxy

add_chan(chan_idx, dflt_val=0.0, rst_val=0.0, nickname=None, proxy_class=<class 'nistreamer.channel.AOChanProxy'>)[source]#

Add an output channel.

Parameters:

  • chan_idx (int) – hardware channel index (as shown in NI MAX)

  • dflt_val (float) – the default value for intervals that are not covered by instructions

  • rst_val (float) – the value set by add_reset_instr() command

  • nickname (str) – human-readable name used for visualizations

  • proxy_class (Optional[Type[AOChanProxy]]) – custom subclass of AOChanProxy to use.

Returns:

Channel proxy instance

Raises:

KeyError – if this hardware channel has been added already

class nistreamer.card.DOCardProxy(_streamer, max_name, nickname=None)[source]#

Bases: BaseCardProxy

add_chan(port_idx, line_idx, dflt_val=False, rst_val=False, nickname=None, proxy_class=<class 'nistreamer.channel.DOChanProxy'>)[source]#

Add an output channel.

Parameters:

  • port_idx (int) – digital port index (as shown in NI MAX)

  • line_idx (int) – digital line index within the port (as shown in NI MAX)

  • dflt_val (bool) – the default value for intervals that are not covered by instructions

  • rst_val (bool) – the value set by add_reset_instr() command

  • nickname (str) – human-readable name used for visualizations

  • proxy_class (Optional[Type[DOChanProxy]]) – custom subclass of DOChanProxy to use.

Returns:

Channel proxy instance

Raises:

KeyError – if this hardware channel has been added already

property const_fns_only: bool#

Shows whether the “constant functions only” mode is enabled.

If enabled, all lines on this card will only accept the following constant-valued instructions: high, low, go_high, and go_low. This restriction allows to accelerate the runtime sample computation and significantly reduce the risk of buffer underflow.

In most cases, only constant-valued instructions are used anyway, so this mode is enabled by default. You only need to disable it if you want to use non-constant boolean waveform functions.