nidaqmx.task.ao_channel
- class nidaqmx._task_modules.channels.ao_channel.AOChannel(task_handle, virtual_or_physical_name, interpreter)[source]
Bases:
nidaqmx._task_modules.channels.channel.ChannelRepresents one or more analog output virtual channels and their properties.
- property ao_common_mode_offset
Specifies the common-mode offset of the AO channel. Use the property only when Terminal Configuration is set to Differential.
- Type
float
- property ao_current_units
Specifies in what units to generate current on the channel. Write data to the channel in the units you select.
- property ao_custom_scale
Specifies the name of a custom scale for the channel.
- Type
nidaqmx.system.scale.Scale
- property ao_dac_offset_ext_src
Specifies the source of the DAC offset voltage if ao_dac_offset_src is SourceSelection.EXTERNAL. The valid sources for this signal vary by device.
- Type
str
- property ao_dac_offset_src
Specifies the source of the DAC offset voltage. The value of this voltage source determines the full-scale value of the DAC.
- property ao_dac_offset_val
Specifies in volts the value of the DAC offset voltage. To achieve best accuracy, the DAC offset value should be hand calibrated.
- Type
float
- property ao_dac_ref_allow_conn_to_gnd
Specifies whether to allow grounding the internal DAC reference at run time. You must set this property to True and set ao_dac_ref_src to SourceSelection.INTERNAL before you can set ao_dac_ref_conn_to_gnd to True.
- Type
bool
- property ao_dac_ref_conn_to_gnd
Specifies whether to ground the internal DAC reference. Grounding the internal DAC reference has the effect of grounding all analog output channels and stopping waveform generation across all analog output channels regardless of whether the channels belong to the current task. You can ground the internal DAC reference only when ao_dac_ref_src is SourceSelection.INTERNAL and ao_dac_ref_allow_conn_to_gnd is True.
- Type
bool
- property ao_dac_ref_ext_src
Specifies the source of the DAC reference voltage if ao_dac_ref_src is SourceSelection.EXTERNAL. The valid sources for this signal vary by device.
- Type
str
- property ao_dac_ref_src
Specifies the source of the DAC reference voltage. The value of this voltage source determines the full-scale value of the DAC.
- property ao_dac_ref_val
Specifies in volts the value of the DAC reference voltage. This voltage determines the full-scale range of the DAC. Smaller reference voltages result in smaller ranges, but increased resolution.
- Type
float
- property ao_dac_rng_high
Specifies the upper limit of the output range of the device. This value is in the native units of the device. On E Series devices, for example, the native units is volts.
- Type
float
- property ao_dac_rng_low
Specifies the lower limit of the output range of the device. This value is in the native units of the device. On E Series devices, for example, the native units is volts.
- Type
float
- property ao_data_xfer_mech
nidaqmx.constants.DataTransferActiveTransferMode: Specifies the data transfer mode for the device.
- property ao_data_xfer_req_cond
nidaqmx.constants.OutputDataTransferCondition: Specifies under what condition to transfer data from the buffer to the onboard memory of the device.
- property ao_dev_scaling_coeff
Indicates the coefficients of a linear equation that NI-DAQmx uses to scale values from a voltage to the native format of the device. Each element of the list corresponds to a term of the equation. The first element of the list corresponds to the y-intercept, and the second element corresponds to the slope. Scaling coefficients do not account for any custom scales that may be applied to the channel.
- Type
List[float]
- property ao_enhanced_image_rejection_enable
Specifies whether to enable the DAC interpolation filter. Disable the interpolation filter to improve DAC signal-to- noise ratio at the expense of degraded image rejection.
- Type
bool
- property ao_filter_delay
Specifies the amount of time between when the sample is written by the host device and when the sample is output by the DAC. This value is in the units you specify with ao_filter_delay_units.
- Type
float
- property ao_filter_delay_adjustment
Specifies an additional amount of time to wait between when the sample is written by the host device and when the sample is output by the DAC. This delay adjustment is in addition to the value indicated by ao_filter_delay. This delay adjustment is in the units you specify with ao_filter_delay_units.
- Type
float
- property ao_filter_delay_units
Specifies the units of ao_filter_delay and ao_filter_delay_adjustment.
- property ao_func_gen_amplitude
Specifies the zero-to-peak amplitude of the waveform to generate in volts. Zero and negative values are valid.
- Type
float
- property ao_func_gen_fm_deviation
Specifies the FM deviation in hertz per volt when ao_func_gen_modulation_type is ModulationType.FM.
- Type
float
- property ao_func_gen_freq
Specifies the frequency of the waveform to generate in hertz.
- Type
float
- property ao_func_gen_modulation_type
Specifies if the device generates a modulated version of the waveform using the original waveform as a carrier and input from an external terminal as the signal.
- property ao_func_gen_offset
Specifies the voltage offset of the waveform to generate.
- Type
float
- property ao_func_gen_square_duty_cycle
Specifies the square wave duty cycle of the waveform to generate.
- Type
float
- property ao_func_gen_start_phase
Specifies the starting phase in degrees of the waveform to generate.
- Type
float
- property ao_func_gen_type
Specifies the kind of the waveform to generate.
- property ao_gain
Specifies in decibels the gain factor to apply to the channel.
- Type
float
- property ao_idle_output_behavior
Specifies the state of the channel when no generation is in progress.
- property ao_load_impedance
Specifies in ohms the load impedance connected to the analog output channel.
- Type
float
- property ao_max
Specifies the maximum value you expect to generate. The value is in the units you specify with a units property. If you try to write a value larger than the maximum value, NI- DAQmx generates an error. NI-DAQmx might coerce this value to a smaller value if other task settings restrict the device from generating the desired maximum.
- Type
float
- property ao_mem_map_enable
Specifies for NI-DAQmx to map hardware registers to the memory space of the application, if possible. Normally, NI- DAQmx maps hardware registers to memory accessible only to the kernel. Mapping the registers to the memory space of the application increases performance. However, if the application accesses the memory space mapped to the registers, it can adversely affect the operation of the device and possibly result in a system crash.
- Type
bool
- property ao_min
Specifies the minimum value you expect to generate. The value is in the units you specify with a units property. If you try to write a value smaller than the minimum value, NI- DAQmx generates an error. NI-DAQmx might coerce this value to a larger value if other task settings restrict the device from generating the desired minimum.
- Type
float
- property ao_output_impedance
Specifies in ohms the impedance of the analog output stage of the device.
- Type
float
- property ao_output_type
Indicates whether the channel generates voltage, current, or a waveform.
- property ao_reglitch_enable
Specifies whether to enable reglitching. The output of a DAC normally glitches whenever the DAC is updated with a new value. The amount of glitching differs from code to code and is generally largest at major code transitions. Reglitching generates uniform glitch energy at each code transition and provides for more uniform glitches. Uniform glitch energy makes it easier to filter out the noise introduced from glitching during spectrum analysis.
- Type
bool
- property ao_resolution
Indicates the resolution of the digital-to-analog converter of the channel. This value is in the units you specify with ao_resolution_units.
- Type
float
- property ao_resolution_units
Specifies the units of ao_resolution.
- property ao_term_cfg
Specifies the terminal configuration of the channel.
- property ao_usb_xfer_req_count
Specifies the maximum number of simultaneous USB transfers used to stream data. Modify this value to affect performance under different combinations of operating system and device.
- Type
int
- property ao_usb_xfer_req_size
Specifies the maximum size of a USB transfer request in bytes. Modify this value to affect performance under different combinations of operating system and device.
- Type
int
- property ao_use_only_on_brd_mem
Specifies whether to write samples directly to the onboard memory of the device, bypassing the memory buffer. Generally, you cannot update onboard memory directly after you start the task. Onboard memory includes data FIFOs.
- Type
bool
- property ao_voltage_current_limit
Specifies the current limit, in amperes, for the voltage channel.
- Type
float
- property ao_voltage_units
Specifies in what units to generate voltage on the channel. Write data to the channel in the units you select.
- property chan_type
Indicates the type of the virtual channel.
- property channel_names
Specifies the unflattened list of the virtual channels.
- Type
List[str]
- property description
Specifies a user-defined description for the channel.
- Type
str
- property is_global
Indicates whether the channel is a global channel.
- Type
bool
- property name
Specifies the name of the virtual channel this object represents.
- Type
str
- property physical_channel
nidaqmx.system.physical_channel.PhysicalChannel: Specifies the name of the physical channel upon which this virtual channel is based.
- save(save_as='', author='', overwrite_existing_channel=False, allow_interactive_editing=True, allow_interactive_deletion=True)
Saves this local or global channel to MAX as a global channel.
- Parameters
save_as (Optional[str]) – Is the name to save the task, global channel, or custom scale as. If you do not specify a value for this input, NI-DAQmx uses the name currently assigned to the task, global channel, or custom scale.
author (Optional[str]) – Is a name to store with the task, global channel, or custom scale.
overwrite_existing_channel (Optional[bool]) – Specifies whether to overwrite a global channel of the same name if one is already saved in MAX. If this input is False and a global channel of the same name is already saved in MAX, this function returns an error.
allow_interactive_editing (Optional[bool]) – Specifies whether to allow the task, global channel, or custom scale to be edited in the DAQ Assistant. If allow_interactive_editing is True, the DAQ Assistant must support all task or global channel settings.
allow_interactive_deletion (Optional[bool]) – Specifies whether to allow the task, global channel, or custom scale to be deleted through MAX.
- property sync_unlock_behavior
Specifies the action to take if the target loses its synchronization to the grand master.