Siemens SINUMERIK 828D Function Manual page 351

Diagnostics
Read reference radius
The value of the reference radius of a rotary axis can be read using system variables:
• For the display in the user interface, in synchronized actions or with a preprocessing stop in the part program
via the system variables:
$AA_FGREF[<axis>]
• Without preprocessing stop in the part program via system variable:
$PA_FGREF[<axis>]
If no values are programmed, the default 360 mm/(2π) = 57.296 mm (corresponding to 1 mm per degree) will be
read in both variables.
For linear axes, the value in both variables is always 1 mm.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
G2: Velocities, setpoint / actual value systems, closed-loop control
Current main run value
Programmed value
7.3 Metric/inch measuring system
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