Siemens SINUMERIK 840Di Function Manual page 740

Detailed Description
2.1 Axes
2.1.8 Positioning axes
Meaning
Positioning axes are interpolated separately (each positioning axis has its own axis
interpolator). Each positioning axis has its own feedrate and acceleration characteristic.
Positioning axes can be programmed in addition to path axes (even in the same block). Path
axis interpolation (path interpolator) is not affected by the positioning axes. Path axes and
the individual positioning axes do not necessarily reach their block end points at the same
time.
Instructions POS and POSA are used to program positioning axes and define block change
criteria:
• POS
• POSA
Concurrent positioning axes differ from positioning axes in that they:
• Only receive their block end points from the PLC
• Can be started at any time (not at block limits)
• Do not affect the execution of current part programs
Application
Typical positioning axes are:
• Loaders for transporting workpieces
• Tool magazine/turret
Reference
References:
/FB2/ Description of Functions, Expansion Functions; Positioning Axes (P2)
/FB1/ Description of Functions, Basic Machine; Spindles (S1)
/FB3/ Description of Functions, Special Functions; Gantry Axes (G1)
/FB2/ Description of Functions, Expansion Functions; Positioning Axes (P2)
/FB3/ Description of Functions, Special Functions; Axis Couplings and ESR (M3)
/FB1/ Description of Functions, Basic Machine; PLC Basic Program (P3)
/FB2/ Description of Functions, Expansion Functions; Oscillation (P5)
/FBSY/ Description of Functions, Synchronized Actions
2-10
Block change takes place when the path axes and positioning axes have reached their
block end points.
Block change takes place when the path axes have reached their end of block position.
Positioning axes continue to traverse beyond block limits to their block end point.
Axis Types, Coordinate Systems, Frames (K2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0