first time you check program speedpot plc is there have speedpot program or not?
if it's the plc inside has program for speedpot, try set speed to 50% then check output analog plc its must be around 5 Vdc.
if ok then connect 0 V from analog output PLC to 0V terminal your DC drive and connect 10V from analog output PLC to terminal Vin for speed control at your DC drive.