Check that the data source is configured correctly and the machine is connected and powered on.

If you are still getting a timeout error, the Run test connection (details below) may be getting blocked by your computer/network firewall. Either try using a different network or contact your IT to make sure the test is not getting blocked.

Direction	Port	Transport protocol	Application protocol
Outbound	443	TCP	WebSocket

If the above is all in order, your machine may not be responding in a timely manner (timeout details below). That may be due to high CPU load or simply outdated hardware.

Timeout
30 seconds

The edge gateway was unable to read one or more variables. These variables have been temporarily blacklisted so that other variables can continue to be read.

There may be a data typing error. Your tag's data type does not match the data type in the PLC. Possible solution:

• Check the correct data type in the PLC, then remove the designated tag from the data source and re-add the tag with the correct data type.
  • It is not possible to change the data type without removing the tag.

The error message may contain a second error, indicating what the problem is. Look up that error below, resolve it, and then reboot the edge gateway.

Data typing error. The designated tag's data type does not match the data type in the PLC. Possible solution:

• Remove the designated tag from the data source and re-add the tag with the correct data type.
  • It is not possible to change the data type without removing the tag.

The edge gateway is reconnecting to the OPC UA server. You should see a different error message shortly.

There is an issue with the client certificate not being trusted by the OPC UA server or the server certificate not being trusted by the edge gateway. This can have multiple causes.

Follow the instructions under Client and server certificates in the main support article to get this resolved: OPC UA data source setup.

Communication error. Possible causes:

• The IP address in the data source is incorrect and does not match the machine.
• The port setting in the data source is incorrect and does not match the port on which the OPC UA server on the machine is listening.
• The firewall on the machine is blocking the edge gateway's OPC UA connection attempts.
• The machine is not running an OPC UA server. Make sure that the machine is compatible with OPC UA and that its OPC UA server is running.

Authentication or security error. Possible causes:

• The username or password in the data source is incorrect and does not match with the required authentication on the machine.
• The configured authentication in the data source is incorrect. Check the authentication settings in the machine and adjust the settings in the IXON Cloud data source accordingly.
• The machine is not compatible with the supported authentication and security methods. Check the authentication and security settings in the machine and adjust them accordingly. On some machines you may need to enable Anonymous, set Message security mode to None, or disable User Administration.

The edge gateway's client certificate does not exist or is not trusted by the OPC UA server.

Follow the instructions under Client and server certificates in the main support article to get this resolved: OPC UA data source setup.

Addressing error. Possible causes:

• The variable does not exist in the machine.
• The variable's address is incorrect.
• If the variable is an element of an array, make sure that in the machine the property Show array elements is set to TRUE. In B&R hardware, this setting is found by going to the Config view, then finding the OPC UA mapping file, and then finding the array.

Connection error. The OPC UA communication between the edge gateway and the machine was abruptly disconnected. Possible solution:

• Make sure that the (physical) connection is stable (e.g. no loose connector or broken cable).

Communication error. Possible causes:

• The IP address in the data source is incorrect and does not match the machine.
• The port setting in the data source is incorrect and does not match the port on which the OPC UA server on the machine is listening.
• The machine is not running an OPC UA server. Make sure that the machine is compatible with OPC UA and that its OPC UA server is running.

Authentication error. The credentials have been rejected by the OPC UA server. Possible causes:

• The username or password in the data source is incorrect and does not match with the required authentication on the machine.
• The username and password are correct, but do not provide the necessary permission on the OPC UA server.
• The authentication settings in the data source are incorrect and do not match with the authentication settings on the machine.

Addressing error. Possible causes:

• The variable does not exist in the machine.
• The variable's address is incorrect.
• If the variable is an element of an array, make sure that in the machine the property Show array elements is set to TRUE. In B&R hardware, this setting is found by going to the Config view, then finding the OPC UA mapping file, and then finding the array.

Authentication or security error. Possible causes:

• The username or password in the data source is incorrect and does not match with the required authentication on the machine.
• The configured authentication in the data source is incorrect. Check the authentication settings in the machine and adjust the settings in the IXON Cloud data source accordingly.
• The machine is not compatible with the supported authentication and security methods. Check the authentication and security settings in the machine and adjust them accordingly. On some machines you may need to enable Anonymous, set Message security mode to None, or disable User Administration.

Addressing error. Possible causes:

• The variable does not exist in the machine.
• The variable's address is incorrect.
• If the variable is an element of an array, make sure that in the machine the property Show array elements is set to TRUE. In B&R hardware, this setting is found by going to the Config view, then finding the OPC UA mapping file, and then finding the array.

The client certificate uploaded onto the OPC UA server may be corrupted. This can have multiple causes. Download the edge gateway's client certificate as new and repeat the steps to trust it on the OPC UA server.

Connection error. The OPC UA server did not timely respond to the edge gateway's OPC UA message. Possible solutions:

• Set the Polling sleep time in the data source to 100 ms or higher to reduce the CPU load on the machine.
• Reduce the CPU load in any other manner.
• Make sure that the OPC UA server is running on the machine.
• Allow the edge gateway's OPC UA connection attempts through the machine's firewall.

Request error. The machine cannot handle the amount of variables that are being requested. The edge gateway will request all configured variables in a single request and the machine can only handle a certain amount of variables per request. Possible solutions:

• Increase the limit in the machine. The setting may be named "Nodes per read operation".
• Remove variables from the IXON Cloud to reduce the number of variables being requested.

The data source's authentication settings are incorrect. Possible causes:

• The username or password in the data source is incorrect and does not match with the required authentication on the machine.
• The username and password are correct, but do not provide the necessary permission on the OPC UA server.
• The authentication settings in the data source are incorrect and do not match with the authentication settings on the machine.