ADLINK PCI-8258 - Manual (Page 113)

Motion Control Theory 99
PCI-8254 / PCI-8258
I32 APS_get_command( I32 Axis_ID, I32 *Command );
I32 APS_set_command(I32 Axis_ID, I32 Command);
I32 APS_get_position( I32 Axis_ID, I32 *Position );
I32 APS_set_position (I32 Axis_ID, I32 Position);
API listed below can read motor coordinates
I32 APS_get_encoder( I32 Axis_ID, I32 *Encoder );
I32 APS_get_command_counter (I32 Axis_ID, I32 *Counter);
4.3.2 Unit Factor
Location unit (or motion mechanism) of motor can have actual
mapping against physical distance unit of coordinate system by
setting up proper unit factor. The calculation formula is described
below
We use three examples to explain the way how Unit factor is
calculated:
Example 1: Ball screw carrier
Assume encoder counts (resolution) generated by one spin of the
motor is 10000 and the screw pitch is 10mm and the user desired
distance unit of measure is micrometer,
NOTE NOTE
In close loop control procedure you cannot set up command
counter and encoder counter and so relevant setup API are not
provided.
(Deductor gea
(Driver gear)
Pitch = 10 mm
M:N = 1:2