Plc/Mcp/Hhu Interface - Siemens SINUMERIK 828D Function Manual

P3: Basic PLC Program for SINUMERIK 840D sl
13.7 Interface structure
13.7.3

PLC/MCP/HHU interface

General
There are three different connection options for the machine control panel (MCP) and the handheld unit (HHU).
This is in part due to the history of the MCP and HHU. This description focuses primarily on the connection of the
Ethernet components.
On SINUMERIK 840 D sl, the machine control panel (MCP) or HT8 (MCP) and handheld unit HT1, HT2 (HHU)
are connected via the Ethernet bus, which also links the TCU to the NCU. The advantage of this is that only one
bus cable is required to connect the operator unit.
Topology SINUMERIK 840D sl
On the 840 D, the machine control panel and the handheld unit are connected to the CP 840D sl Ethernet bus
(see Figure below). Where the connection of further keys and displays is required for customized operator
panels, an additional keyboard interface (machine control panel without operating unit) can be used. For each
keyboard interface, 64 pushbuttons, switches, etc. and 64 display elements can be connected via ribbon cable.
The signals sent from the MCP are copied to the PLC's DPR (Dual Port RAM) by the integrated Ethernet CP-
840D sl. The basic program of the PLC enters the incoming signals in the input image configured on FB1. The
NC­related signals are generally distributed by the basic program to the VDI interface. If required, the signals can
be modified by the user.
The signals from the PLC to the MCP (displays) are transferred in the opposite direction.
Figure 13-10 Connection of the machine control panel on 840D sl
Basic Functions
873
Function Manual, 09/2011, 6FC5397-0BP40-2BA0