Siemens Simatic CFU Commissioning Manual page 101

Note
Replacement of a CFU without disturbing other parts of the system
If one of the following variants is selected for the structure of a CFU, you can replace this CFU
without influencing other parts of the system:
● CFU in a star topology
● CFU in a ring topology when MRP is used
Procedure
You can find information on the tightening torques in section "Tools and tightening torques
(Page 149)".
Carry out the following steps to replace a CFU:
Step
1 Disconnect cables of sensors/actuators and field devices from the CFU.
2 Disconnect the power supply (PS1/PS2) and the BusAdapter (terminal X5 of the CFU) from the CFU.
3 Replace the CFU.
Recommendation:
● Observe the information in the requirements for automatic name assignment and setting of the IP address on
device replacement.
● Configure the new CFU before installing it in the system.
If the CFU has at least the same IO device name as the replaced CFU, the CPU automatically writes the IP
address to the CFU.
4 Insert the connectors of the sensors/actuators and field devices to the connections of the CFU (FB<n> and
DIQ<n>).
Switch on the separate supply of connected field devices.
5 If necessary, fasten the shield connection of the cables.
If available and necessary, you can fasten the cables to the shielding bus with cable ties.
6 Insert the BusAdapter (terminal X5 of the CFU).
7 Connect power supply cables (PS1 to X80 / PS2 to X81).
Switching on the CFU
You can find information about this in section "Switching on the CFU (Page 51)".
Note that you have to download the parameters of the CFU using PDM.
SIMATIC CFU
Commissioning Manual, 07/2018, A5E39252870-AC
Servicing and maintenance
10.4 Replacing the CFU
101