We have made a few changes to the PLC program, so we need to update the HMI to reflect the changes. Only problem is the HMI is not wanting to update its program. First we tried copying the program onto a memory card, then sticking it into the slot on the back of the HMI. The HMI sees the program on the card, but once we tried the download (with observations that the download was a successful) , the HMI reverted to the original program. Then we tried both an online download via ethernet and a wired download via a serial cable and the corresponding adapter. Both failed due to the processor being unable to establish a connection with the PLC. Maybe I am having a problem with the routing table from the PLC? I successfully downloaded an update to the HMI a few weeks ago with no issues. Now it seems that the PanelView is unreachable.