Siemens SINUMERIK 840D sl Function Manual page 220

Several Operator Panels on Several NCUs, Distributed Systems (B3)
Examples
Figure 2-42
Figure 2-43
220
MMC_1 server, wishes to switch operating focus from NCU_1 to NCU_2, switchover
disabled in PLC_1
MMC_1 is server, wishes to switch operating focus from NCU_1 over to NCU_2,
switchover is disabled in PLC_2
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions