Siemens SINUMERIK 840D sl Function Manual page 1016

Detailed description
2.5 Linking PLC CPUs to 810D, 840D
2.5.3 Interface on 810D and 840D with integrated PLC
Physical interfaces
As the 810D and 840D systems have an integrated PLC, signals can be exchanged between
the NCK and PLC directly via a dualport RAM.
Exchange with operator panel and MCP
Data are generally exchanged with the operator panel (OP), machine control panel (MCP)
and handheld unit (HHU) on the 840D via the operator panel interface (OPI), the COM
module being responsible for data transport.
All devices specified above can also be operated on the multipoint interface (MPI) in the
case of the 840 D. With the 810D, data communication with the operator panel (OP),
machine control panel (MCP) and handheld unit (HHU) takes place only via the MPI.
The programming device is connected directly to the PLC via the MPI (multipoint interface).
Figure 2-2
32
NCK/PLC connection on 810D, 840D (integrated PLC)
Basic logic functions: PLC Basic program powerline (P3 pl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0