Siemens SINUMERIK 808D ADVANCED Series Commissioning Manual page 152

● Hardware solution (MD14512 [18] bit 6 = 1)
This solution is independent of the PLC and thus is much safer:
Encoding the hardware limit switches
E_Key _1LMTp
0 1
0 0
0 0
0 0
0 0
0 0
0 0
In the hardware solution above, the feed stop signals for all axes can be activated via the hardware limit switches when any
of the hardware limits is reached or an EMERGENCY STOP happens. You can check the information of the PLC diagnostics
from the encoding of the hardware limit switches shown in the table above, and identify the cause (Emergency Stop button
or a hardware limit switch of an axis) of the EMERGENCY STOP signal.
Note
When using the hardware solution, you must take below information into consideration:
You must assign the axes one by one; for example, X axis, Z axis, spindle or X axis, Y axis, Z axis, spindle. You must not
•
assign the axes like X axis, Y axis, spindle, Z axis.
You must set constant "1" (i.e. SM0.0) to the input signals of the hardware limits for undefined axes; otherwise, the
•
hardware limits of the undefined axes can be activated.
Local variable definition
Inputs
Name Type
nodef WORD
NC_Ready BOOL
_1LMTp BOOL
_1LMTn BOOL
_1REF BOOL
_2LMTp BOOL
152
_2LMTp _3LMTp
1 1
1 1
1 1
0 1
0 1
0 0
0 0
Description
Reserved
NC being in the cyclic state and able to enable the drive
Positive hardware limit switch of 1st axis (NC)
Negative hardware limit switch of 1st axis (NC)
Reference cam of 1st axis (NO)
Positive hardware limit switch of 2nd axis (NC)
Direction
-
DB3900.DBX4.7
DB3900.DBX4.6
DB3901.DBX4.7
DB3901.DBX4.6
DB3902.DBX4.7
DB3902.DBX4.6
1)
1)
6FC5397-4EP10-0BA8, 07/2018
Result
EMERGENCY STOP
active
1st + over limit
1st - over limit
2nd + over limit
2nd - over limit
3rd + over limit
3rd - over limit
Commissioning Manual