PowerMid is really an Infra Red Remote extender product. It consists of two units, one IR-receiver and one IR-transmitter. They communicate via a 433MHz radio link. The idea is that you put the receiver in one room (where you are) and the transmitter in another room (where for example your DVD-Player is) and you can control the DVD-Player with your remote via the PowerMid radio link.
Via the NetHomeServer CUL Connection, the NetHomeServer can tap in on that radio link. This means that a NetHomeServer with a CUL-transmitter can use a PowerMid as an IR transmitter and thereby control home appliances via IR.
NetHomeServer has built in support for the Pronto protocol, which is a standard for describing IR signals, so if you have the Pronto codes for your device, you can use NetHome to control it.
The related Items in the NetHomeServer are: