Read/Write I/O FAQs

Q: How can I access digital input results?

The Read/Write I/O step logs selected measurements when the step is executed. You can access the measurement results by using a subsequent step that can access measurement results. Examples of steps that can use measurement results are, but not limited to, the Modbus Slave, Serial I/O, TCP I/O, Run LabVIEW VI, Calculator, Logic Calculator, and Custom Overlay steps.

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

When a system signal is associated with a digital output line, the digital output line is updated whenever the system signal changes. Once a digital output line is associated with a system signal, the line always outputs the current state of the system signal. You can reassign the source for a digital output line using another Read/Write I/O step. All other reads and writes occur when the step executes. It is recommended to use a Read/Write I/O step in the Setup state for system signal output because once the step is called the configured digital output line updates the system signal while the main inspection runs.