Siemens SINUMERIK 840D sl Function Manual page 481

Figure 6-3
TYPE input
In principle, the PLC must set the signal "Request new type". It is deleted again after
change. Also for a channel interchange with GET and RELEASE (only 840D sl).
Controlling PLC axes/spindles for 840D sl
PLC axes and PLC spindles are traversed using function block FC18 in the basic PLC
program
FC18: SpinCtrl Spindle control
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Changing an axis from K1 to K2 via parts program
K5: Mode groups, channels, axis interchange
6.4 Axis/spindle replacement
481