Resolve VISA Warning: Unable to Read All Data

These remedies apply when you receive some data and you get this warning message:

'visadev' unable to read all requested data

Try these remedies to resolve the following causes when you use the VISA interface for reading binary data using the read function.

Cause	Solution
The number of values to read was set to a higher value than the number of values available to be read.	Confirm that you set the correct number of values to read with the `read` function. For information about setting the number of values to read, see `read`.
Device did not send all the requested data or communication with the device was interrupted.	Check your device connection. For more information about troubleshooting configuration and connection, see Troubleshooting VISA Interface.
There was a data format mismatch.	Verify that the device data type matches the specified read data type. Specify the data type with `read`. For more information about supported data types, see `read`.
The timeout value might be too short for the amount of data being read.	Increase the `Timeout` property value. For more information about setting the property, see Timeout.

See Also