Siemens SINUMERIK 840D sl Function Manual page 1029

User Program
The user PLC program merely needs to call the basic program block FC10 with appropriate
parameter settings in the cyclic program section and set or reset the bit fields in DB2. All
further necessary measures are implemented by the basic program and HMI software.
Figure 2-8
2.6.4 PLC/MCP/HHU interface
General
On the SINUMERIK 840D/810D, the machine control panel (MCP) is connected on the same
bus that connects the OP with the NC. The advantage of this is that only one bus cable is
required to connect the operator unit. The handheld unit (HHU) can be connected to the MPI
of the PLC or to the operator panel interface (OPI) (840D only). However, since the OP bus
on the 840D supports higher baud rates, two different types of bus topology are provided.
Basic logic functions: PLC Basic program powerline (P3 pl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Acquisition and signaling of PLC events
Detailed description
2.6 Interface structure
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