Siemens SINUMERIK 840D Function Manual page 665

Figure 17-2
Example 2: Manual traversing using a handwheel, stop condition is a cancellation criterion
If a stop condition is selected as cancellation criterion via machine data
MD32084 $MA_HANDWH_STOP_COND or
MD20624 $MC_HANDWH_CHAN_STOP_COND during manual traversing using a
handwheel, no travel command is output, but the corresponding travel request is output.
When the stop condition is removed, the corresponding "Travel request" NC/PLC interface
signal is reset, as an abort is present. The stop condition is no longer active, but the axis cannot
be traversed as the stop condition has caused an abort.
In addition, either the distance specification (MD11346 $MN_HANDWH_TRUE_DISTANCE
== 1 or == 3) is active or the handwheel is moved continuously, i.e. it provides pulses.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
Signal-time diagram:Manual traversing using the handwheel with distance input, stop
condition is not a cancellation criterionMD17900 $MN_VDI_FUNCTION_MASK bit 0 = 1
H1: Manual traversing
17.6 Manual traversing using a handwheel
665