Spindle speed in Counterclockwise Wrong

Thank You ! Now i know how to make my own HAL components.
 
   

I see I get some number errors in GetSpeed but think it is a Modbus issue

Glad to hear it's working.

In regards to Modbus/RS485, try to use a USB or RS232 to RS485 adapter with A/B and GND. Add a 120 Ohm resistor only on the last device between A/B. The GND will help to reduce potential EMI emissions. A twisted pair cable is also a good choice for RS485.