DigitalOutput

Prerequisites:

bonsai DAQmx Library
NI DAQmx driver from the NI website

Category: Sink

Brief: Writes a sequence of logical values to one or more DAQmx digital output channels

Input (bool)

Properties:

Channels (System.Collections.ObjectModel.Collection<Bonsai.DAQmx.DigitalOutputChannelConfiguration>) - all analog output channels that the voltage signal will be fed to, specified by adding channels in the DigitalOutputChannelConfiguration Collection Editor and setting its parameters as appropriate:
- ChannelName - can be anything
- Grouping - specifies how to group digital output lines into virtual channels; if one or more ports are specified with the Lines parameter, this must be OneChannelForEachLine (instead of OneChannelForAllLines)
- Lines - the physical digital output line on the board, selected from the drop-down list once the device is connected

Output (bool)

tip

A boolean square pulse can be generated by sampling from FunctionGenerator (BufferLength = 1) one item at a time and applying a threshold (e.g. using GreaterThan) to obtain output of type bool. This method seems to work well for SamplingRate <= 100 Hz. Note that Frequency must be less than half of the SamplingRate value in line with the Nyquist Sampling Theorem.

Digital pulse

If higher frequency signals are needed, a combination of FunctionGenerator and AnalogOutput can be used instead (where possible).

caution

Runtime Error: Device cannot be accessed

Most likely happens because the NI-DAQmx device is not connected/powered. Several other possible reasons and remedies are listed in the bonsai error message.