Voltage Ranges and Settings

The NI 654x uses the following four logic families to control the device voltage levels:

• 1.8 V Logic
• 2.5 V Logic
• 3.3 V Logic
• 5.0 V Logic

Selecting one of these logic families determines the NI 654x generation levels or acquisition thresholds. For mixed-voltage systems the generation levels and acquisition thresholds can be set independently. For example, you can set the Generation Voltage Family to 1.8 V Logic while you set the Acquisition Voltage Family to 5.0 V Logic. By synchronizing and operating multiple NI 654x devices, you can use multiple generation or acquisition voltage configurations in the same system.

Note  The maximum generation voltage of the NI 654x is 3.3 V. Therefore, setting the Generation Logic Family to 5.0 V Logic produces a 3.3 V signal, which is compatible with standard 5 V TTL input thresholds. Refer to the NI 654x specifications for details.

The Generation Logic Family selection sets the voltage levels used for all data, clock, and event generations, including the exported PLL reference clock. The Acquisition Logic Family selection sets the levels used for all acquired data, clock, and trigger signals, except for the CLK IN SMB jack connector. Refer to Clock Sources Summary for acceptable CLK IN signal characteristics.

When programming your device using NI-HSDIO, the functions and instance VIs for configuring voltage levels are named according to the type of channel (data, trigger, or event) that you want to configure.

For more information about voltage level ranges and resolutions, refer to the NI 654x specifications.