Siemens SINUMERIK 840Di Function Manual page 1256

Detailed Description
2.7 Structure and functions of the basic program
A user program copy routine to copy the signals of the active MCP from the I/O area
configured in HW Config to DB77. This enables a number of MCPs on the PROFIBUS to be
switched via signals. Set the MCPxStop parameter to True for the switchover phase from
one MCP to another.
One method will be outlined now with the Ethernet variants of MCP and HHU.
Control signals
Parameters MCP1Stop, MCP2Stop and BHGStop can be used to stop communication with
individual components (parameter setting = 1). This function is available only on Ethernet
variants. This stop or activation of communication can be applied in the current cycle.
However, the change in value must be implemented through the symbolic notation of the
parameters and not by means of another FB 1 call.
Example of stopping transfer from the first machine control panel:
SET;
S gp_par.MCP1Stop;
Setting parameters MCP1Stop, MCP2Stop, BHGStop also results in a suppression or
deletion of interrupts 400260 to 400262.
Bus address switchover
An existing connection with a machine control panel (MCPl) or handheld unit (HHU) can be
aborted. Another MCP or HHU component already connected to the bus (different address)
can then be activated. Proceed as follows to switch addresses:
1. Stop communication with component to be decoupled via parameter MCP1Stop or
2. Following checkback in DB10 byte 104 (relevant bits 0, 1 and 2 are set to 0), the bus
3. In this PLC cycle, communication with the new component can now be activated again by
4. Communication with the new component is taking place when the checkback is in DB10
2-62
MCP2Stop or BHGStop = 1.
address (with MCP, this is the FB1 parameter "MCP1BusAdr" or "MCP2BusAdr"; with
HHU Ethernet variant, the bus address is set at FB1 parameter "BHGRecGDNo") of this
unit is changed to the new component.
means of parameter MCP1Stop or MCP2Stop or BHGStop = 0.
byte 104 (relevant bits 0, 1, 2 are set to 1).
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0