Siemens SINUMERIK 840D Function Manual page 215

Examples of NC responses
PLC actions as response of the NC are listed in the table below.
PLC actions
Machine axis AX1 is the channel axis in channel 1,
start as PLC axis using FC18
Initiate NC stop axes and spindles
DB21, ... DBX7.4 = 1 (NC stop axes plus spindle)
DB21, ... DBX7.1 = 1 initiate (NC start)
The PLC wants to control AX1,
DB31, ... DBX28.7 = 1 (PLC controls axis)
Initiate NC stop for axes and spindles
DB21, ... DBX7.4 = 1 ("NC stop axes plus spindle")
Initiate axial stop
DB31, ... DBX28.6 = 1 (stop along braking ramp)
Initiate axial continuation
DB31, ... DBX28.2 = 1 (continue)
Initiate NC RESET
DB21, ... DBX7.7 = 1 initiate (reset)
Initiate axial reset
DB31, ... DBX28.1 = 1 (reset)
Start machine axis AX1 as PLC axis via FC 18
Withdraw controller enable for AX1:
DB31, ... DBX2.1 = 0 (controller enable)
Initiate axial continuation
DB31, ... DBX28.2 = 1 (continue)
Set controller enable for AX1
DB31, ... DBX2.1 = 1 (controller enable)
Initiate axial reset
DB31, ... DBX28.1 = 1 (reset)
PLC relinquishes control of AX1 to the NC from
DB31, ... DBX28.7 = 0 (PLC controls axis)
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
6.7 Control by the PLC
NC response
AX1 is stopped.
AX1 continues to traverse.
Checking AX1 is relinquished to the PLC. DB31, ...
DBX63.1 = 1 (PLC controls the axis)
AX1 is not stopped.
AX1 is stopped
DB31, ... DBX63.2 ==1 (axis stop active)
AX1 traverses further
DB31, ... DBX63.2 == 0 (axis stop active)
No effect on AX1
AX1 is stopped and the traversing motion is inter‐
rupted:
● DB31, ... DBX63.2 = 0 (axis stop active)
● Read-in axial machine data
● DB31, ... DBX63.0 = 1 (reset executed)
● DB31, ... DBX63.2 = 0 (axis stop active)
DB31, ... DBX63.0 = 0 (reset executed)
Alarm 21612 "Axis %1 measuring system change"
is displayed
● Alarm 21612 "Axis %1 measuring system
change" is deleted
● DB21, ... DBX40.7 = 1(traversing command
plus)
● AX1 does not traverse due to a missing
controller enable signal.
AX1 moves to the programmed end point.
● Stop AX1
● Read-in axial machine data
● DB31, ... DBX63.0 = 0 (reset)
● NC accepts control of machine axis
● DB31, ... DBX63.1 = 0 (PLC controls the axis)
● DB31, ... DBX63.0 = 0 (reset)
P2: Positioning axes
215