Remora - ethernet NVEM / EC300 / EC500 cnc board

[code]//********************************************************
This is a fragment of code from other project
Not for copy/paste, only for explanation
//********************************************************

// EC500 side
// fb. prefix means variables will send from EC500 to hal component

struct fbPacket {
    float raw_encoder;
    float encoder_latched;
} fb = { 0.0, 0.0 };

fb.raw_encoder = encoder.getCount();
void index_ISR1() {        // interrupt handler
  fb.encoder_latched  = encoder.getCount();
}

//********************************************************

// Hal component side
// fb. prefix means variables received from EC500
// index_ena is i/o hal pin for connect to spindle.0.index_enable
// pos_scale is hal input pin
// period is LinuxCNC global variable
// pos and vel are hal output pins
// Not need anything else for synchronising spindle

float old_pos;
float latched_enc;
float encoder_latched_old;
float delta_pos;
float delta_time;
struct FB {
    float raw_encoder;
    float encoder_latched;
} fb = { 0.0, 0.0 };

            if  ((encoder_latched_old != fb.encoder_latched) && (index_ena)) {
            latched_enc = fb.encoder_latched;
        old_pos = (fb.raw_encoder - latched_enc);
            index_ena = false;
            }
            encoder_latched_old = fb.encoder_latched;

   pos = (fb.raw_encoder - latched_enc) / pos_scale;
   delta_pos = pos - old_pos;
   old_pos = pos;
   delta_time = period * 1e-9;
   vel = delta_pos / delta_time;
   
//********************************************************