I've had the priveledge of working with a few Yaskawa drives, and I know that almost all of them are a Modbus slave out of the box (2 or 4-wire, RS485). I know for sure that the F7 is. You can also get add-on cards; I know of EthernetIP/Modbus TCP, Devicenet, and Profibus. The add-on cards run about $4-500. This would give you access to pretty much everything, even drive parameters. You could start/stop, control frequency/speed, and monitor current remotely.