Siemens SINUMERIK 840D sl Commissioning Manual page 383

Figure 18-3 System with several NCUs and a fixed modem
The "MC Information System RCS Host" option only has to be set for the NCU to which the
TS Adapter is connected at the X127 interface. Modem access can only be permitted by
making the appropriate entries at the SINUMERIK Operate in this NCU and the "Request
remote control" function executed. If modem access is permitted, then the service PC
implicitly has access to all other NCUs and their operating software. On the other hand, the
operating screens to control the remote access can be used and set at each station
(SINUMERIK Operate in the NCU) individually for the station in conjunction with the relevant
local PLC.
SINUMERIK Operate (IM9)
Commissioning Manual, 03/2013, 6FC5397-1DP40-3BA1
Service and diagnostics
18.13 Remote diagnostics
377