Voltage range from +-2 to +-10Volts for Yaskawa SGDH Driver

Hello everyone,
I'm using a 5i25 in combination with a 7i77 to retrofit an old CNC cross-slide. I already had the 7i77 so analog speed control is the easiest way to go, but how can I offset the voltage? From what I know old analog driven drivers are normally -10V to 10V without that weird -2V to 2V gap.
Would appreciate the help, thanks in advance.

I don't think there is a +-2V gap

I think the drive can set its input gain to
accommodate input ranges from +-2V to +-10V full scale
 

That would make so much more sense. Weird that they don't describe it as gain. Thank you