Most automation systems can export PAD. TRE Message Manager software from Broadcast Electronics reads that program associated data, integrates your near- and non-PAD messaging content, formats it for your HD Radio or RDS gear and then injects the formatted data stream into the air chain.
You'll also need equipment capable of managing the transport and transmission of the encoded data. For RDS, the encoded data is a UDP or serial stream and can be transported from studio to transmitter using STLs with data transport capability.
To take advanatage of some of The Radio Exeperience's more advanced features, TRE will need internet access over port 80. For HD Radio, the STL must have IP transport capability if the data is encoded at the studio site.