Inline Hardware Interface Custom Devices

An inline hardware interface custom device executes inline with the VeriStand Engine's Primary Control Loop (PCL) and enables you to read and write data from and to a hardware device.

You can create a standard inline hardware interface custom device from a template in the Custom Device API library. This also applies to the Inline Timing and Sync device type, which is an inline hardware interface device that you add to the system definition file as a timing and sync device.

An inline hardware interface custom device executes as a state machine, or action-engine. The device contains a Case structure, and the PCL calls each case at a specific time with respect to other components of the VeriStand Engine. Within the device, an uninitialized Feedback Node handles iterative data transfer between states.

Note You can use additional Feedback Nodes or other storage mechanisms, such as functional global variables, in an inline custom device.

The inline hardware interface custom device is similar to the inline model interface custom device. An inline hardware interface custom device has two cases, or steps, that execute within an iteration of the PCL. An inline model interface custom device has only one step that executes within a PCL iteration.