Siemens SINUMERIK 840Di Function Manual page 952

Detailed description
2.6 Interface structure
The signals arriving from the machine control panel are copied by the COM module into the
DPR (dualport RAM) for transfer to the NC. The NC in turn transmits them to the PLC (VDI
task). The basic program of the PLC enters the incoming signals in the input image. The NC-
related signals are generally distributed by the basic program to the VDI interface. This can
be modified by the user if required.
The signals (displays) from the PLC to the MCP (displays) are transferred in the opposite
direction.
The signals of the handheld unit (HHU) are transferred either via the operator panel interface
in the same way as via the machine control panel or by means of the GD service (GD =
Global Data) of the MPI interface. The PLC operating system enters the HHU data, for
example, in the input image and transfers the display values, e.g., from the output image,
back to the HHU. The corresponding parameters are set via system data block SDB210,
which is generated with the STEP7 communication configuration tool.
Fig. 2-9
810D topology
On the 810D, the machine control panel, handheld unit and OP are connected to the MPI
(multipoint Interface) of the AS 300. The transmission rate in this configuration is 187.5
Kbps. The PLC operating system copies the incoming signals straight to the user interface
(e.g., input image) at the cycle control point.
Transfer to the VDI interface is performed, as on the 840D, by the user program or by a
standard routine of the basic program.
2-40
Connection of the machine control panel for 810D
Power Line Basic PLC Program (P3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0