The AN-X2-AB-DHRIO Gateway is designed to help customers initiate a phased migration approach to replacing or upgrading legacy Remote I/O PLCs. HMI’s. Drives or Flex I/O Adapters. These solutions can be achieved by selecting the corresponding operation mode during initial configuration. The AN-X2-AB-DHRIO has a built-in web server that can display diagnostics data. configuration. upload configuration files. and set the operation mode.