Analog & Digital I/O
You can use the analog and digital I/O functions to control the general-purpose analog and digital I/O resources on the NI motion controller. These resources include up to 32 bits of general-purpose digital I/O, PWM outputs, RTSI lines, and any extra encoders, ADC channels, and DAC outputs that are not mapped to an axis.
The 32 bits of digital I/O are available on the Digital I/O Connector. These bits are organized into 8-bit ports that you can configure as inputs or outputs on a port-wise basis, or on a bitwise basis. Each bit has individually programmable polarity that you can configure as active low or active high. You can use the general-purpose digital I/O for system integration applications including operator panel switch inputs and outputs, relay and solenoid activation, trigger I/O between other controllers and/or instruments in the system, and so on.
You can use encoders, ADC channels, and DAC outputs that are not mapped to an axis for general-purpose I/O. Typical uses for encoder inputs include velocity monitoring, masters for master-slave gearing, and digital potentiometer applications.
You can use unused ADC inputs and DAC outputs for any analog I/O that is within their specifications. Typical analog input applications include analog joysticks, potentiometers, force, pressure, level and strain sensors, and so on. Analog output applications vary from heater element control to laser intensity modulation.