Mpi/Opi Network Rules - Siemens SINUMERIK 840D sl Function Manual

B3: Several operator panels connected to several NCUs, distributed systems - only 840D sl
At any given time, only one preselected NCU can be connected to the HMI Advanced
operator panel for operations:
● HMI Embedded also only has one connection for alarms.
● HMI Advanced: The PCU remains connected to all NCUs for alarms.
References
/BH/ Operator Components Manual
/IAD/ Commissioning Manual
/FB1/ Function Manual, Basic Functions, Basic PLC Program (P3)
/FB2/ Function Manual, Extended Functions; Memory Configuration (S7)
The following are described here:
● MPI/OPI bus structure, bus addresses (IAD)
● Bus terminator (IAD, FB2)
● Connection of MCPs via basic PLC program (FB1)
● DIP FIX settings of MCP (IAD)
2.1.3.4

MPI/OPI network rules

Network installations
Please take the following basic rules into account when undertaking network installations:
● The bus line must be terminated at both ends. To do this, you switch on the terminating
● It is necessary to apply a 5 V voltage to at least 1 terminator.
● Drop cables (feeder cable from bus segment to node) should be as short as possible.
● Each MPI node must first be connected and then activated.
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
resistor in the MPI connector of the first and last node, and switch off any other
terminators.
Note
Only two inserted terminating resistors are permitted.
In the case of HHU/HT6, bus terminating resistors are permanently installed in the
device.
This is automatically supplied as soon as the MPI connector with the terminating resistor
fitted is connected to an activated device.
Note
Any spur lines that are not assigned should be removed if possible.
When disconnecting an MPI node, first deactivate the connection, then remove the
connector.
2.1 Brief description
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