Siemens SINUMERIK 840D sl Programming Manual page 475

Sequence
The axis that is requested at the time the action GET (axis) is activated can be read with
respect to axis type for an axis replacement via the system variable
($AA_AXCHANGE_TYP[<axis>]:
• 0: Axis assigned to NC program
• 1: Axis assigned to PLC or active as command axis or oscillating axis
• 2: Another channel has the interpolation right
• 3: Axis is neutral axis
• 4: Neutral axis is controlled by PLC
• 5: Another channel has the interpolation right, axis is requested for NC program
• 6: Another channel has the interpolation right, axis is requested as neutral axis
• 7: Axis active for PLC or as command or oscillating axis, axis is requested for PLC
• 8: Axis active for PLC or as command or oscillating axis, axis is requested as neutral axis
Boundary conditions
The axis concerned must be assigned to the channel via machine data.
An axis controlled exclusively by the PLC cannot be assigned to the NC program.
References:
/FB2/ Function Manual, Extended Functions; Positioning Axes (P2)
Using GET to request an axis from another channel
If, when the GET action is activated, another channel is authorized to write (has the
interpolation right) to the axis ($AA_AXCHANGE_TYP[<axis>] == 2), axis replacement is
used to get the axis from this channel ($AA_AXCHANGE_TYP[<axis>]==6) and assign it to
the requesting channel as soon as possible.
The axis then becomes the neutral axis ($AA_AXCHANGE_TYP[<axis>]==3).
There is no reorganize in the requesting channel.
Assignment as NC program axis with reorganize:
If an attempt to make the axis the neutral axis is already in progress when the GET action is
activated ($AA_AXCHANGE_TYP[<axis>]==6), the axis is requested for the NC program
($AA_AXCHANGE_TYP[<axis>]==5) and assigned to the NC program on the channel as
soon as possible ($AA_AXCHANGE_TYP[<axis>]==0).
Job planning
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
program
Motion synchronous actions
10.4 Actions in synchronized actions
10-49