Siemens SINUMERIK 840D sl Function Manual page 119

B3: Several operator panels connected to several NCUs, distributed systems - only 840D sl
Suppression strategy
The PLC program "Control Unit Switchover" operates according to the
● priorities of the control units and
● the active processes
The priority depends on the parameter mmc_typ in configuration file NETNAMES.INI (see
Section "Structure of the configuration file"). The Control Unit Switchover program on the
PLC evaluates this parameter according to the following table:
HMI property
Server
Main control panel
Secondary control panel
OEM-MMC 3
OEM-MMC 2
OEM-MMC 1
OEM-MMC 0
Suppression rules
The following rules apply for control unit suppression:
● Higher priority suppresses lower priority.
● In the event of identical priority, the active control unit is suppressed.
The following restrictions apply:
● Servers cannot be suppressed, as they require a permanent connection to each NCU.
● Control units on which the following processes are active cannot be suppressed:
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
2.2 Several operator panel fronts and NCUs with control unit management option
– Data transfer, e.g. from/to NCU
– Control unit is in the process of switching over to this NCU
– Control unit is just changing operating mode
– OEM disables switchover
Priority
6
5
4
3
2
1
0
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