Help with renco encoder/motor

I purchase 2 servo motors on e-bay over 1 year ago. I am at last
putting together the cnc controller but I have no documentation at
all. I don't need the motor data, but I do need to know how to hook
up the encoder. It is a renco encoder, it is just over 2"diameter
and just under an inch in height. on the side is a barcode with the
ID # of zmtr 004391. the encoder wire colors are :blue,green,black
(blank),red,yellow,and white.

The motor is 4" diameter 5.75 "length with a 1/2 inch shaft.


Any help, especially with the encoder, would be much appreciated

Bill. H