Sometimes when the PLC and HMI are hooked up together and operating under the EV5000 software, a PLC error may appear. To troubleshoot the error, simply use a numeric display and set it to the PLC register the data is being written to. If this PLC register comes back with random register values, this indicates that the HMI did not deliver the information to that register. If it was sent correctly, then the numeric displays should show the information that was sent. This is a very simplistic way of solving HMI/PLC errors. See Anaheim Automation's Video Tutorials for more help with programming an HMI.