Siemens SINUMERIK 840D sl Function Manual page 237

B3: Several operator panels connected to several NCUs, distributed systems - only 840D sl
MCP switchover:
As an option, an MCP assigned to the PCU can be switched over at the same time. This can
be done on condition that the MCP address is entered in parameter mstt_adress of PCU
configuration file NETNAMES.INI and MCPEnable is set to true. The MCP of the passive
PCU is deactivated. so that there is only ever one active MCP on an NCU at one time.
Power-up condition:
To prevent the previously selected MCP being reactivated when the NCU is restarted, input
parameters MCP1BusAdr = 255 (address of 1st MCP) and MCP1STOP =TRUE (deactivate
1st MCP) must be set when FB1 is called in OB 100.
Enabling commands:
When one MCP is switched over to another, any active feedrate or axis enabling signals may
be transferred at the same time.
NOTICE
Keys actuated at the moment of switchover remain operative until the new MCP is activated
(by the HMI, which is subsequently activated). The override settings for feedrate and
spindle also remain valid. To deactivate actuated keys, the input image of the machine
control signals must be switched to non-actuated signal level on a falling edge of
DB10.DBX104.0. The override settings should remain unchanged.
Measures for deactivating keys must be implemented in the PLC user program. (see below:
Example of override switchover)
Declaration of the function
FUNCTION_BLOCK FB9
VAR_INPUT
Ack : BOOL; //Acknowledge alarms
OPMixedMode: BOOL:= FALSE ; // Mixed operation with non M:N-capable
// OP deactivated!
AktivEnable : BOOL:= TRUE ; // Activate active/passive switchover.
MCPEnable : BOOL:= TRUE ; // Activate MCP switchover
END_VAR
VAR_OUTPUT
Alarm1 : BOOL ; // Alarm: Error in PCU bus address, bus type!
Alarm2 : BOOL ; // Alarm: No confirmation MMC1 offline!
Alarm3 : BOOL ; // Alarm: MMC1 is not going offline!
Alarm4 : BOOL ; // Alarm: No confirmation MMC2 offline!
Alarm5 : BOOL ; // Alarm: MMC2 is not going offline!
Alarm6 : BOOL ; // Alarm: Requesting PCU is not going online!
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
2.15 Examples
237