Read/Write I/O (NI-DAQmx) FAQs

Q: When a digital output line writes a system signal, when is the line updated?

When a digital output line is associated with a system signal, the line is updated whenever the system signal changes. Once a line is associated with a system signal, the line always outputs the current state of the system signal. All non-system signals are updated when the step is run.

Q: How can I access the digital and analog input results?

The Read/Write I/O (NI-DAQmx) step logs all of the selected measurements when it is executed. The measurements can then be accessed from any future step that can use previous measurement results and is in the same state as the Read/Write I/O (NI-DAQmx) step. Create a variable and use the Set Variable step to access measurement results from other inspection states.

Q: Why can I not read analog output values?

The Read/Write I/O (NI-DAQmx) step does not support reading analog output values. This is because reading analog output values is not currently supported by the NI-DAQmx driver software.

Q: What happens if I try to write a value to an analog output line that is outside of the voltage range of the channel?

When you attempt to write a value that is outside of the range, Vision Builder AI coerces the value to the nearest valid value. The coerced value is then output on the analog output line and the Analog Output Name Coerced measurement result is set to TRUE to indicate that the value was coerced. Analog Output Name is the name of the analog output line to which the value is output.