Siemens SINUMERIK 840Di Function Manual page 954

Detailed description
2.6 Interface structure
MCP interface in the PLC
The signals from the machine control panel are routed via the I/O area by default. A
distinction is made between NC and machinespecific signals. NCspecific key signals are
normally distributed by FC 19 to the various mode group, NCK, axis and spindlespecific
interfaces. The reverse applies to the status signals, which are routed to the machine control
panel interface.
Note
FC 19 must be called in the PLC user program.
Customized keys, which can be used to trigger a wide range of machine functions, must be
evaluated directly by the user program. The user program also routes the status signals to
the output area for the LEDs.
Fig. 2-11 Interface to and from machine control panel
2-42
Power Line Basic PLC Program (P3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0