I have nearly zero experience with Mitsubishi PLCs, but have used the Digi One IAP as a serial to Ethernet bridge in cases where I needed to access Allen Bradley serial only PLCs with both programming software and HMI drivers. I would expect that it could be configured to work for you.
If you want a data collection device that can handle logging and protocol conversion but don't need a bridge for programming software to use, most any of Red Lion HMI or data station devices can probably handle it.