There are two Ethernet network ports on the IX and Windows will decide which one is Default for that particular Windows installation. Windows selection of which one is "Default" can change if the drivers for the ports ever get reloaded or Windows updated.
Since our driver configurations are generally set to use the Default Ethernet port to communicate to the PLCs, it is possible that even though all the driver configuration is correct and the PLC is online and ping-able, that the driver does not work. This can be due to the IP address of the card Windows decides is "default" not being the correct one for your system configuration.
The easiest way to fix it (at least rule it out) is to swap IP addresses on the two cards and swap the Ethernet cables from one to the other.
To change which port Windows uses as the "Default", there is a detailed description of how to change the priority of Ethernet connections on the Microsoft web site. https://support.microsoft.com/en-us/kb/2526067
Unlike previous versions, Windows 10 automatically orders connections based on connection speed. It's not recommended to change the order unless there is a problem with how Windows 10 is selecting your default connection.
- Open the Network and Sharing Center > Change Adapter Settings.
- Right click the connection whose priority you wish to modify then click Properties.
- Scroll down and click Internet Protocol Version 4 (TCP/IPv4), then click Properties.
- In the bottom of the properties window, click Advanced.
- On the bottom of the Advanced Settings window, uncheck the box next to Automatic Metric.
- In the Interface Metric text box, enter the priority number for this connection.
- Note: The lower the number, the higher the priority the connection will have. Enter any number that is 2 or greater, depending on your preference for this connection.
DM 03/24/2020 added Win 10