It looks like the GV-U6E can recieve an analog control signal or a digital signal such as Step/Dir or CW/CCW. Servo systems usually use an analog control signal although the 7344 can produce either since stepper systems usually used the digital signals. You will want to connect the +/- 10 V Cmd to the Analog Output and Analog Output Ground on the UMI. This is the signal that is going to control the motor. Then you also need to connect your encoders to the UMI so that you have feedback. Your drive also requires the enable to be wired which you can do as shown in their manual with a physical switch as a kill switch independent of software.
The manual for the UMI might also be helpful for you which can be found here: http://digital.ni.com/manuals.nsf/websearch/AC6F
AA69218C9624862567BD0061DDAC?OpenDocument&node=132100_US
Regards,
JAndrews