Maintenance
7-11
AutomationSystem S7-400 Hardwareand Installation
A5E00850741-01
7.6 Replacing Interface Modules
Slot Numbering
If you have provided the modules in your system with slot numbering, you must
remove the number from the old module when replacing it and apply the number to
the new module.

Hot--swappingModules

Observe the following warning when fitting and removing the interface modules and
the corresponding connecting cables.
!Caution
Data can be lost or corrupted.
If you remove or insert the interface modules and/or corresponding connecting
cables with power applied, data may be lost or corrupted.
Switch off thepower supplymodules of the CR and ERs on which you are working
before carrying out any actions.

Removing Modules / Exchanging Cables

1. Ifyou wish to back up your data in the CPU, you can do this with a backup
battery or via an external battery supply at the CPU (see the CPU Data
Reference Manual, Chapter 1).
2. Setthe CPU mode switch to STOP.
3. Setthe standby switches of both power supply modules (in the CR and the ER)
to (0 V output voltages).
4. Removethe cover.
5. Disconnectthe connecting cables.
6. Disconnectthe terminator, if applicable.
7. Loosenthe mounting screws of the module.
8. Swingthe module out.