There are many reasons that questions marks might show up on your control panel or HMI software. The most common reason is a networking issue, meaning the software cannot communicate with the control hardware.
After confirming that your IT Department, Networking team, or Internet Security Provider has not recently made any changes AND that your control panel has power and is powered on, follow through these steps to see if you can resolve the issue:
1. Are all networking cables still connected at their proper connection points?
2. Are the lights on the network switch all flashing for each cable that's connected? (The network switch is typically on the top right of the control panel.
3. Is your PLC faulted?
3a. You can check for a fault by looking on your PLC in your main control cabinet. If there is a RED light on OK or on FAULT, contact our support and we'll see what we can do to solve the issue.
4. Can you open the software menu? Typically the ICS or MEI logo on the top left. This menu may show you a PLC IP Address, is there an address typed in the field to the right of "PLC Address" or "PLC IP"?
5. If there is an address in that field, a more advanced check that you could make is to ping the IP address. To do so:
5a. Click on your start menu and search "Command Prompt"
5b. Open Command Prompt
5c. Type "Ping" and the IP Address from your control screen. i.e. "Ping 10.10.100.70"
5e. If it can communicate with it you should get a response similar to the attached image. If it cannot reach the address, it'll say "Destination host unreachable".
If you are unable to communicate with the PLC or get the question marks to go away after all of these steps, please reach out to our support team and we'll give you hand.