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 That may be due to high CPU load or simply outdated hardware.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
1 second

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.

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.

The variable's address is incorrect or the variable does not exist in the machine.

If the error message shows a range of variables (e.g. [0-13]), the problem may be the communication. Set the Read mode setting in the data source to Optimized. If the problem persists, make sure that the variable's addresses are correct and that the variables exist in the machine.

Incorrect slave ID. Check the slave ID on the machine and correct the slave ID in the data source accordingly.

The machine isn't accepting new Modbus connection requests. There may be a limit to the number of concurrent Modbus connections allowed on the machine and they may already be in use. Make sure there is no other Modbus communication taking place and then restart the machine and edge gateway.