Resolve VISA Warning: Unable to Read Any Data

Issue

These remedies apply when you receive no data and you get this warning message:

'visadev' unable to read any data

Possible Solutions

Try these remedies to resolve the following causes for when you use the VISA interface for:

• Reading ASCII (text) data using the readline function.

• Reading binary data using the read function.

• Reading binblock data using the readbinblock function.

Cause	Solution
The device did not receive the command because of an incorrect resource name. You might have connected to the wrong device.	Verify that the device is associated with the resource name that you specified when you created the visadev object.
An invalid command was sent to the device, so there is a problem reading the response to the command.	Check your device documentation for proper command formatting.
An incorrect write terminator was configured before attempting to read data, so there is no data to read.	Verify that the Terminator property is set to the value required by your device. For more information about setting the property, see configureTerminator.
The device is not configured to read binblock data.	Configure the instrument for binblock data. Check your device documentation.

Try these steps for the VISA-Serial interface:

Cause	Solution
Your device is connected to an incorrect serial port.	Verify that your device is connected to the specified port. It must match the port you specify when you create the visadev object.
Your device is not configured to send data on the serial port.	Verify the device communication settings.

Try these steps for the VISA-Socket interface:

Cause	Solution
Your device did not receive the command because either the TCP/IP remote host address or the remote port is incorrect.	Verify that the device is at the remote host address that you specified, and is listening on the remote port that you specified when you created the visadev object.