NI PCI-6723
The National Instruments PCI-6723 is a PCI based AO Series card. Please see the National Instruments' website for the NI PCI-6723 data sheet. The Rapid Control Prototyping Toolkit driver name for this card is ni_pci_6723 .
Clocks
This card is part of the DAQmx API, and therefore the hardware clocks cannot be directly accessed. The clocks can only be set indirectly with the functions that utilize them such as the timebase VIs.
Only one timebase VI may be present in a diagram. In addition, an immediate VI for the same type of channel can not be used even if they use different resources. For instance, if a HIL Read Timebase Analog (Scalar) VI is in use, you cannot also have a HIL Read Analog (Scalar) VI in the diagram, even if the two VIs do not read the same analog input channels.
The HIL Read Timebase VI only supports a buffer size of 1. The same holds true of the task creation functions. When adding a timebase VI, you must change the Samples in buffer field or you will receive the error "The specified buffer size is not valid. It may be out of an acceptable range."
Analog Inputs
The NI PCI-6723 card does not support analog inputs.
Analog Outputs
The NI PCI-6723 supports 32 analog outputs (channels 0 to 31) with 13-bit resolution.
The valid output ranges are ±10V, so it is not necessary to specify the range in the HIL Initialize VI.
In order to have analog outputs set to a particular voltage when the block diagram is run or stopped, the analog outputs must be configured on the HIL Initialize VI's Analog Outputs tab. Set the Initial analog outputs and Final analog outputs to the desired voltage values.
Digital I/O
The NI PCI-6723 supports 8 bidirectional digital lines (lines 0 to 7).
A digital I/O line cannot be used as an input and output at the same time.
Since the digital I/O lines may be individually programmed as inputs or outputs, the direction of each digital I/O line should be configured on the HIL Initialize VI's Digital I/O tab.
To set the digital output values when the block diagram is run or stopped, set the Initial digital outputs and Final digital outputs to the desired values respectively.
Encoder Inputs
The NI PCI-6723 supports 2 quadrature encoder inputs with 24-bit count values (channels 0 and 1). Note that since this card uses its counters for both encoder inputs and PWM outputs, you can only use a counter as either an encoder input or a PWM output channel.
In order to set the encoder counters to a particular count or to change the default quadrature when the block diagram is run, the encoder inputs must be configured on the HIL Initialize VI's Encoder Inputs tab. The NI PCI-6723 supports non-quadrature (count and direction), 1X quadrature, 2X quadrature and 4X quadrature. The NI PCI-6723 does not support encoder filtering.
PWM Outputs
The NI PCI-6723 supports 2 24-bit PWM Outputs using its 2 counters (channels 0 and 1). The PWM outputs on this card use a counter timebase rate of 80 MHz. Note that since this card uses its counters for both encoder inputs and PWM outputs, you can only use a counter as either an encoder input or a PWM output channel.
In order to configure the PWM mode or frequency, or to set the value of the PWM outputs when the block diagram is run or stopped, the PWM outputs must be configured on the HIL Initialize VI's PWM Outputs tab. The Initial output checkbox should always be checked.
Set the PWM output mode field to the desired output mode. The NI PCI-6723 supports all the PWM output modes: duty cycle, frequency or period. See the description of the HIL Initialize VI for details on these modes. Then set the PWM output frequency in Hz or duty cycle field to the desired frequency or duty cycle. Note that this card is part of the National Instruments' DAQmx API and one of the limitations of this API is that you cannot output a PWM signal with a 0% or 100% duty cycle. Furthermore, a value of 0 for frequency is also not acceptable. When in duty cycle mode, the acceptable range of duty cycles are:
Note that the PWM signal period is the frequency inverted. Therefore, the acceptable value for duty cycle is related to the frequency at which the signal is being generated. In frequency mode, the acceptable range of frequencies are related to the duty cycle of the signal and are as follows:
In period mode, the maximum and minimum values for period are reciprocals of the minimum/maximum values for frequency above.
As mentioned earlier in this section, the counters cannot be used as both encoder inputs and PWM outputs. Attempting to do so would produce an error message. |
Due to the DAQmx API limitations, a value of 0 (0%) and 1 (100%) for duty cycle is not accepted. Also, a frequency or a period with value of 0 is also unacceptable. However, attempting to command a value which is out of range does not produce an error. The driver simply saturates the value at the limits. |
Other Inputs
The NI PCI-6723 card does not support other inputs.
Other Outputs
The NI PCI-6723 card does not support other outputs.
Interrupts
The NI PCI-6723 card, or its driver, does not support any interrupt sources.
Watchdog
The NI PCI-6723 card does not support a watchdog timer.
Board-Specific Options
The NI PCI-6723 card does not support any board-specific options.
Properties
The NI PCI-6723 card does not support any properties.
Targets
Target |
Supported |
Comments |
---|---|---|
Yes |
Fully supported. |
See Also
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