For some Saleae devices, the maximum sample rates are only available in certain configurations:
For Logic Pro 8 and Logic Pro 16, the maximum digital sample rate (500 MSPS) can only selected when only 4 or fewer digital channels are active, and all analog channels are disabled.
If you are still not able to select 500 MSPS, it could be caused by using a USB 2.0 connection instead of a USB 3.0 connection. Review this article: The Saleae Logic Pro 8 or Logic Pro 16 is only operating over USB 2.0 on a USB 3.0 port, or any Saleae device does not work properly on a USB 3.0 port, but does work over USB 2.0
For the new Logic 8, the maximum digital sample rate of 100 MSPS can be selected when 3 or fewer digital channels, and no analog channels.
For Logic 4, there are no restrictions.
For the original Logic16, the maximum sample rate of 100 MSPS can only be selected when 3 or fewer channels are active.
The original Logic has no restrictions.
If you can select a sample rate, but are unable to record at that sample rate (the capture ends with an error) please see this article: The device is not successfully capturing data consistently
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