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Resolve UDP Port Warning: Unable to Read Any Data


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

'udpport' unable to read any data

Possible Solutions

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

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

  • Reading binary data using the read function.

An invalid command was sent to the destination UDP port, so there is a problem reading the response to the command.Check the manual of the destination device for proper command formatting.
An incorrect write terminator was sent to the destination UDP port 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 destination UDP port. For more information about setting the property, see configureTerminator.
The destination UDP port did not receive the command because of an incorrect destination port value.Verify that the UDP destination port value is set to the port number the device is listening on. For more information about setting the destination port, see write or writeline.
A firewall is blocking incoming UDP packets.Verify that your system firewall setting allows connections to LocalPort.
The UDP packet size is larger than the maximum packet size that can be handled by the Ethernet adaptor.The UDP packet size is controlled by the OutputDatagramSize property. You can specify the size, in bytes, between 1 and 65507, and the default value is 512.

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