Synchronization

Synchronized operations are created by routing timing and control signals. Synchronization can be within a single device—for instance, synching analog input and analog output on an E Series device—or on multiple devices. Timing and control signals that synchronize operations fall into three categories: clocks, triggers, and events.

These timing and control signals are routed by connecting two terminals together. Selecting a terminal as the source of a clock or a trigger constructs a route. On PCI devices, the RTSI bus provides the pathways for signal routing. On PXI devices, the PXI trigger bus provides the same pathways. For NI-DAQmx to find a free PXI trigger line, you must perform a PXI chassis identification in MAX. For NI-DAQmx to find a free RTSI line, you must create a RTSI cable in MAX and populate it with the devices connected by the cable. You can discover what routes are possible by referencing a table of possible routes in MAX.

The particular timing and control signals to route between two synchronized operations will be determined by the types of devices you are using. Programming two E Series devices to perform analog input in lockstep requires sharing their Master Timebases and Start triggers (or alternatively, their Sample Clocks or AI Convert Clocks). Programming two DSA devices to do the same thing requires sharing their Sample Timebases, a SYNC pulse, and a Start Trigger.