Downgrading an H-CPU
If a CPU in your S7-400H fails, order a new CPU with the same article number. This comes
with the latest firmware version. This firmware can be higher than the predecessor CPU. In
this case, the new CPU must be set to the older firmware version.
1. Insert the new CPU into your automation system.
Note
Do not connect the fiber-optic cable to the CPU of an H system.
2. Select this CPU in HW Config or SIMATIC Manager.
3. Select the menu command PLC > Update Firmware.
The "Update Firmware" dialog box opens.
4. Select the firmware file that corresponds to the version of the predecessor CPU.
5. Download this file to the CPU. The new CPU now has the same firmware version as the
previously used CPU.
6. Now connect the fiber-optic cable for the CPU of an H system.
Switch the system to the "Redundant" operating mode by starting this CPU.
You can then upgrade both CPUs of the H system to the latest firmware in the "Run" state.
Difference of the firmware update to a non-redundant system
Following the actual firmware update, a self-test starts automatically for the H-system. This
function may take several minutes. This time period depends on the amount of load memory
(size of the inserted memory card) and the amount of working memory.
Updating an H-CPU with an operating system update card
You can find additional information on this at the following Internet address:
http://support.industry.siemens.com/cs/products (
http://support.industry.siemens.com/cs/
products?search=Firmware-Update%20S7%20400H
%20CPU&dtp=Download&o=DefaultRankingDesc&
)
3.3.4
Updating an interface module
3.3.4.1
Updating an interface module (IM)
Introduction
The interface modules (IM) in PCS 7 provide the interfaces for a fieldbus between the central
rack of the automation system and the distributed I/O. Interface modules are integrated in bus
links (e.g. DP/PA-Link) and in distributed I/O devices (e.g. ET 200M).
Bus links are gateways between bus systems and enable the communication connection of
the bus systems. Bus links usually consist of an interface module and a fieldbus coupler.
Ensuring Availability
3.3 Hardware update
Service Support and Diagnostics (V8.2)
Service Manual, 03/2016, A5E36200111-AA
39