HFE Front-End Power Supplies TDK-Lambda HFE Power Supplies allow users to remotely program, measure, and check the status of power supplies by using standard TCP/IP networks (LAN, WAN, Internet). The LAN option is designed to communicate with single or multiple supplies in a rack or multiple racks housing HFE power supplies. The user can install and remove the HFE LAN module with no disruption to the operation of the HFE power supplies. A web page browser can be used to operate the module through a built-in web page server. The HFE power supplies offer full remote programming functions.