Siemens SINUMERIK 840D sl Function Manual page 81

Address assignments
Bus nodes each have a unique address on the bus.
The NCU uses:
● A common address for the NC and PLC on the OPI
● Two separate addresses (for NC and PLC) on the MPI interface
Defaults for OPI
Addresses 0 (PG diagnostics) and 14 (HT6) are reserved at the factory and 13 (NCK) is
defined as the default. These addresses should not be assigned to bus nodes in M:N
systems.
● Address 0
● Address 13
Defaults for MPI
● Address 2
● Address 3
Number of active PCUs/HT6s on 1 NCU
A maximum of two PCUs/HT6s (incl. COROS OPs) can be constantly actively connected to
one NCU. PCUs/HT6s on the OPI or MPI count in the same way.
Extended Functions
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Several Operator Panels on Several NCUs, Distributed Systems (B3)
The following applies:
– The PLC address can be reconfigured with STEP7.
"2" is the default address for the PLC on the MPI.
– The following applies for the addresses on the MPI interface:
NC address = PLC address + 1
Is reserved for PG diagnostics.
Note
The M:N switchover can malfunction when a PG is online.
Remedy:
Either set the PG to offline before switching the unit over or connect it to the MPI
interface.
Is defined as the default for service/commissioning.
It is possible to reconfigure this address via HMI operation. Reserve the address for the
"NCU replacement" service case if possible.
For PLC
For NCU
2.1 Brief Description
81