Is there any configuration necessary to get the ECOM100 to talk Modbus TCP?
This depends. If you are going to use the ECOM100 as a Modbus TCP server (slave), then there is no configuration necessary (except for the normal IP Address). However, if you plan on using the ECOM100 as a Modbus TCP client (master), then you have to configure the Peer-to-Peer parameters. This is done using NetEdit3 (right-click on ECOM100, select Peer To Peer Configuration), or an HTML Browser (select Peer to Peer).