Direct SPI communication

To whom it may concern:
I have about 7 or 8 VSD-E drives, and currently I have one 3x mill that I am using 3 drives in and controlling them in torque mode with the analog in. I would like to switch the communication to use SPI rather than the analog input, as when I first start up the mill the slight voltage on the analog input causes the axis to take off, and can potentially cause a crash. It is quite unnerving.

So I would like to switch the communication directly to SPI. Do you have any documentation on how to control these drives directly using SPI. I looked up the documentation on your SimpleMotion utility, but what do you use to communicate to the drive directly through SPI? Are there any special commands?

Here is the controller that I am using. Please let me know this is possible to do.
RS232 with KFLop
Thank you,
Dave