unidrive sp analog out question

Hi

I have a question regarding unidrive sp analog out. I have a sp0205 driver which control a motor using close loop vector mode.
The speed referance coming from HMI. one analog output from driver go to siemens analog module EM235 which send the speed display to HMI. This analog output hook up to driver's T9 terminal. The parameter Pr 7.19 points to Pr 3.02 which is drivr's speed feed back. The value of Pr 3.02 is negative number.
But when I measure from EM235 terminal I got positive voltage value. The question is this voltage should be positive or negative corresponding to Pr 3.02 negative number?

I guess that your problem lies in the way that the analog signal is scaled the PLC system.

Try to view this as it probably will help you to solve the problem:
http://support.automation.siemens.com/WW/view/en/27043396

I check the Plc program which scale the analog value properly. The problem is that when I increase the speed reference the speed display on HMI decrease. The analog voltage( positive value) from driver increase fellow the speed reference accordingly. But inside PLC I do see the input value decrease. why?

What value do you get from the analog module, when watching before scaling block??

Is the connection from the drive to the analog module done correctly?
http://support.automation.siemens.com/WW/view/en/14955836