PLC Subroutines Manual
6FC5397-0FP40-0BA0, 08/2013
41
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
Table 3-7
Inputs
Name
Type
Description
NODEF
WORD
Reserved word
NC_Ready
BOOL
NC being in the cyclic state and able to enable the drive
OPTM
BOOL
Brake release switch (NO), used for drive optimization, reserved
_1LMTp
BOOL
1st axis hardware limit (NC)
1)
_1LMTn
BOOL
1st axis hardware limit switch - (NC)
_1REF
BOOL
1st axis reference cam (NO)
_2LMTp
BOOL
2nd axis hardware limit (NC)
1)
_2LMTn
BOOL
2nd axis hardware limit switch - (NC)
_2REF
BOOL
2nd axis reference cam (NO)
_3LMTp
BOOL
3rd axis hardware limit (NC)
1)
_3LMTn
BOOL
3rd axis hardware limit switch - (NC)
_3REF
BOOL
3rd axis reference cam (NO)
_4REF
BOOL
Reserved
1)
The hardware limit + is used for the input if there is only one hardware limit switch or when the hardware solution is
used.
Table 3-8
Outputs
Name
Type
Description
OVlmt
BOOL
Over-distance output (active at any hardware limit, high active )
Assigned global variables
SP_CMD
M138.1
Spindle start command (CW or CCW)
Relevant PLC machine data
No.
Value
Description
14512 [18].6
1
Overtravel employs the hardware solution
0
Overtravel employs the PLC solution
14512 [18].7
1
Each axis has only one hardware limit switch
0
Each axis direction has an hardware limit switch
14512 [20].1
0
Disable by pressing the spindle stop key
1
Disable when detecting the standstill speed
1)
