Siemens SINUMERIK 840D sl Function Manual page 821

11.7 Control by the PLC
PLC axes
PLC axes are traversed by the PLC via special function blocks in the basic program; their
movements can be asynchronous to all other axes. The travel motions are executed
separate from the path and synchronized actions.
Reference: /FB1/ Function Manual, Basic Functions; "Basic PLC Program" (P3)
Concurrent positioning axes
Function blocks FC 18 (Function Call)
The PLC can start concurrent positioning axes with function block FC 18.
Channel-specific signals
All channel-specific signals act to the same extent on path and positioning axes.
The following signals are the only exceptions (see Chapter 5):
● IS DB21, ... DBB4 ("Feedrate override")
● IS DB21, ... DBX6.2 ("Delete distance to go")
Axis-specific signals
The following additional signals are available for positioning axes (see Chapter 5):
● IS DB31, ... DBX76.5 ("Positioning axis")
● Feedrate for positioning axes/spindles (FA)
● IS DB31, ... DBB0 ("Feedrate override") axis-specific
● IS DB31, ... DBX2.2 ("Distance to go/Spindle reset") Axis-specific deletion of distance to
Single-axis functions of PLC-controlled axes
The behavior of individual PLC axes can be manipulated in the following way with machine
data MD30460 $MA_BASE_FUNCTION_MASK:
● Bit 4 = 1, the axis is controlled solely by the PLC
● Bit 5 = 1, the axis is a permanently assigned PLC axis
● Bit 6 = 1, the channel-specific signal IS DB21, ... DBX6.0 ("feed disable") does not apply
● Bit 7 = 1, the channel-specific signal IS DB21, ... DBX36.3 ("all axes stationary") is set
Extended Functions
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
go
to an axis which is controlled by the PLC.
independently of an axis which is controlled by the PLC.
Positioning Axes (P2)
Control by the PLC
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