Configuring CP 443-1 Firmware Versions and Handling Firmware Mismatches in Redundant PCS 7 Systems

In SIMATIC PCS 7 V8.1 SP1, when installing a physical CP 443-1 Industrial Ethernet processor (MLFB 6GK7443-1EX30-0XE0) bearing firmware V3.1 or replacement V3.29 while the PCS 7 hardware catalog only lists V3.0, it is fully supported to configure the module as firmware V3.0 in HW Config under the 'PCS 7 V8.1' profile. Never switch to the 'Standard' catalog profile to insert uncertified firmware, as this disables Driver Wizard diagnostic chart generation. In redundant fault-tolerant controllers (S7-400H / AS 410-5H), operating partner CPs with mismatched firmware (e.g., V3.1 and V3.29) is strongly discouraged; both modules should be upgraded to the identical latest firmware revision.

Hardware Catalog Filtering: PCS 7 Profile vs Standard Profile

When configuring communications processors in SIMATIC PCS 7 HW Config, engineers frequently notice that the physical hardware received from the factory bears a newer firmware revision than what appears in the hardware catalog. For example, a CP 443-1 (6GK7443-1EX30-0XE0) arrives with firmware V3.1 or replacement spare part firmware V3.29, but the HW Config catalog only displays firmware V3.0.

The Catalog Filter Architecture

In the HW Config catalog pane (top right), SIMATIC Manager provides a profile selector:
* PCS 7 V8.1 Profile (Certified): Displays only modules, interface types, and firmware revisions that have undergone full system testing and certification by Siemens Process Automation development. Modules selected from this profile are fully integrated with the CFC Driver Wizard ('Generate module drivers').
* Standard Profile (Unfiltered Step 7): Displays every factory automation module and firmware revision known to Step 7.

Critical Rule: Switching to the 'Standard' profile to insert a CP with FW V3.1 causes the CFC Driver Wizard to treat the module as an unreleased Step 7 device. The compiler will fail to generate diagnostic @Charts (MOD_, OB_BEGIN, RACK), leaving the communication interface without automated asset management or system diagnostic alarms.

Backward Compatibility and Configuration Rules for CP 443-1

Siemens Industrial Ethernet communication processors are engineered with strict downward compatibility (backward compatibility).

The Backward Compatibility Principle

If the physical CP 443-1 hardware module has firmware V3.1 or V3.29 installed, but the PCS 7 catalog only lists V3.0:
1. Configured Version: Configure the CP 443-1 in HW Config as Firmware V3.0 under the PCS 7 V8.1 catalog profile.
2. Runtime Execution: Upon receiving the configuration download, the physical CP 443-1 running FW V3.1/V3.29 recognizes the V3.0 parameter set, operates in backward-compatible V3.0 mode, and communicates normally.
3. Driver Wizard Harmony: The CFC Driver Wizard identifies the module's certified V3.0 profile, generating all diagnostic blocks and connections without error.
4. Hardware Support Packages (HSP): Never install generic Step 7 HSP packages into a PCS 7 installation unless an official Siemens PCS 7 Hardware Upgrade Package (HUP) is released.

Firmware Mismatches in Redundant Fault-Tolerant Configurations

A critical challenge arises when a faulty CP 443-1 in a redundant S7-400H or AS 410-5H system is replaced by Siemens spare parts service. If Rack 0 contains the original CP with firmware V3.1, and the replacement module for Rack 1 arrives with firmware V3.29:

The Risk of Mixed Redundant Firmware

While basic S7 communication and S7-H Named Connections may initialize with mixed firmware, running redundant partners with mismatched firmware in permanent production is not recommended by Siemens:
* Redundancy Failover Anomalies: Firmware updates frequently alter internal TCP socket keep-alive timers, buffer pools, and ARP broadcast handling. During a high-load plant bus event or controller failover, subtle differences in firmware execution latency can delay redundant connection switchover.
* Firmware Upgrade Solution: The correct engineering response is to upgrade the older CP 443-1 (Rack 0) to match the newer firmware version (V3.29). Firmware download packages are available on Siemens Industry Online Support and can be loaded over Industrial Ethernet using the Step 7 utility PLC -> Update Firmware.

CP 443-1 Hardware, Firmware, and Catalog Compatibility Matrix

The following table outlines configuration and operational compatibility rules for CP 443-1 Industrial Ethernet processors in PCS 7:

Physical Module MLFBPhysical FirmwareConfigured FW in HW ConfigRecommended Catalog ProfileSupported in Redundancy with Mixed FW?6GK7443-1EX30-0XE0V3.0V3.0PCS 7_V81Yes (Matched pair)6GK7443-1EX30-0XE0V3.1V3.0PCS 7_V81Yes (Matched pair running V3.1)6GK7443-1EX30-0XE0V3.29V3.0PCS 7_V81Yes (Matched pair running V3.29)6GK7443-1EX30-0XE0V3.1 (Rack 0) / V3.29 (Rack 1)V3.0PCS 7_V81Not Recommended (Upgrade Rack 0 to V3.29)Any CP 443-1AnySelected from 'Standard'StandardProhibited (Breaks Driver Wizard)

Configuring V3.0 from the PCS 7 catalog ensures full diagnostic integration while maintaining hardware compatibility.

Verification

To verify proper operation of the CP 443-1:
1. In HW Config, verify that the CP is configured as FW V3.0 under the PCS 7 V8.1 profile and downloaded to the AS.
2. In SIMATIC Manager, select the CP and press Ctrl+D (Module Information):
* Verify that the module state indicates 'OK' with green indicator.
* Under the General tab, note that the physical firmware reports V3.1 or V3.29 while functioning properly.
3. Open NetPro and confirm that all S7-H Connections across both CP modules report 'Configured and active'.
4. Compile CFC with 'Generate module drivers' and confirm that diagnostic @Charts for the CP are generated with zero errors.
5. In WinCC Runtime, verify that S7 Named Connections to the OS Servers report bidirectional data flow.

Limitations and Operational Precautions

Never attempt to update CP 443-1 firmware while the automation station is controlling an active production process; firmware updates halt module communication during flash writing.
Do not install Step 7 Hardware Support Packages (HSP) on a PCS 7 engineering station; HSPs can destabilize the PCS 7 Driver Wizard.
If performing a firmware upgrade over the network, ensure the PG/PC has a direct, reliable Ethernet link and disable all power-saving modes.
Verify that physical switch ports connected to CP 443-1 modules are set to auto-negotiation or fixed 100 Mbit/s Full Duplex matching the module settings.

Engineer FAQ

Can I configure FW V3.0 in HW Config if the physical CP 443-1 has FW V3.29?

Yes. Siemens communication processors are 100% backward compatible. Configuring the latest certified catalog version (V3.0) allows physical modules with newer firmware to function seamlessly.

Why shouldn't I select the CP from the 'Standard' catalog profile?

Selecting from the Standard profile bypasses PCS 7 system certification. The Driver Wizard will not generate diagnostic blocks (CPU_DIAG, @Charts), leaving you without automated hardware fault alarms.

How do I update the firmware on a CP 443-1 in an S7-400 rack?

In SIMATIC Manager, open HW Config, select the CP 443-1, and choose menu PLC -> Update Firmware. Select the downloaded .upd firmware files and download them across Industrial Ethernet.