Understanding the Analog Output Latency of the PXIe-7890

Issue Details

I am reading through the datasheet of the PXIe-7890, under the Analog Output and Low-Latency Analog Output subsections, I can see that Update Latency includes Uncalibrated ,Calibrated, and Analog latency values. How do I understand this? What are the differences between those values, and how do I compute the total hardware latency?

Solution

The PXIe-7890 helps engineers work with signal-level inverter hardware-in-the-loop applications. The module features multiple types of I/O, including Analog Outputs and Low-Latency Analog Outputs. Depending on your situation, it can be crucial to determine how fast these analog outputs update.

The datasheet of the device shows three different values, Uncalibrated Update Latency, Calibrated Update Latency, and Analog Latency. The Total Latency of the PXIe-7890 device is divided into these two components, the Update Latency and the Analog Latency. This can be represented as:
  The Analog Latency is a fixed value of 75 ns for the analog outputs and 50 ns for the low-latency analog outputs. However, the Update Latency depends on the output mode the device is using. If the device uses the uncalibrated mode, then its Update Latency equals 440 ns for the analog outputs and 148 ns for the low-latency analog outputs. If the devices is under the calibrated mode, then its Update Latency equals 460 ns for the analog outputs and 168 ns for the low-latency analog outputs.

The difference between the uncalibrated and calibrated modes is that the device uses the stored scaling coefficients in the latter.