Thank you for your reply.
The servo-pack that I am wanting to control, is a Yaskawa SGDV5R5A01A .
Link
http://www.yaskawa.com/site/products.nsf/ProductDetailPages/Servo%20Amplifiers~SGDV%20Sigma-5~SGDVSigma5ModelNumberDesgination.html
I was expecting to be able to control the servo-pack with a 4-20ma, 0-20ma or 0-10v, but it seems to be controlled by a pulse train and I have no knowledge of how to use the 570 to do this.