If you attempt to configure the I2C clock on the USB-8451 over the maximum of 250kHz (e.g. 400kHz) you get the error -301702: 'NI-845x: The supplied clock rate is too low. Refer to your hardware documentation for supported clock rates'. Any value up to 399 kHz is accepted by the configuration property. Trying to communicate afterwards with a clock setting between 250 and 399 kHz results in Warning 301700: 'NI-845x: The passed-in clock rate was lowered to a clock rate value that the hardware supports. Refer to your hardware documentation for supported clock rates.'
On the other hand the configuration property accepts an clock rate setting of 1kHz without errors. The manual lists a minimum of 32 kHz. If you try to communicate afterwards, the same error number as above (-301702) shows up.
Should be corrected in driver software!
