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.