What sampling rate can I reach with Quanser Q2-USB and Q8-USB data acquisition devices?
The Q2-USB and Q8-USB have ‘Normal Mode’ and ‘Fast Mode’ options that determine the max samping rate that can be reached.
- Fast Mode: The base communications rate is 125 us but the effective control rate is 4000 Hz. This mode is very intensive on the CPU and requires a higher end PC to reach the high control rates.
- Normal Mode: The base communications rate is 1 ms but the effective control rate is 500 Hz. This mode is not CPU intensive and will generally work well on most PCs.
The board specific options are on the main tab of the HIL Initialize block. There should be a “…” button to the right of the boards-specific options which will bring up a second dialog where you can switch between normal and fast modes.
Alternatively, change the board specific options directly on the text line from “update_rate=normal” to “update_rate=fast”. If the string isn’t currently in the list of options, then just append it to a list (options are separated by semicolons e.g. update_rate=fast;ext_int_polarity=0; etc).
This image is an example of the Board-Specific Options window when Q8-USB DAQ is selected.