Deploying CP 443-1 (6GK7443-1EX30-0XE0) in Legacy PCS 7 V7.1 SP2 as a Spare Part Replacement

Yes, the SIMATIC NET CP 443-1 module (6GK7443-1EX30-0XE0) can be successfully deployed in a legacy SIMATIC PCS 7 V7.1 SP2 system by configuring it as its predecessor module, CP 443-1 EX20 V2.0 (6GK7443-1EX20-0XE0), in STEP 7 HW Config. Under Siemens 'deploying new hardware as a replacement' spare part compatibility rules, the EX30 hardware automatically operates in backward compatibility mode without CPU stop or configuration errors. However, functionality is constrained to the capabilities of the configured EX20 V2.0 module, and advanced EX30-specific features remain disabled.

Siemens Spare Part Compatibility Principles for Communications Processors

Industrial facilities operating long-lifecycle distributed control systems like SIMATIC PCS 7 V7.1 SP2 often encounter scenarios where original hardware modules (such as the CP 443-1 EX20 6GK7443-1EX20-0XE0) become obsolete and are replaced by newer generational hardware (such as the CP 443-1 EX30 6GK7443-1EX30-0XE0).

Siemens guarantees backward spare-part compatibility under PCS 7 Compendium Part D (Operation and Maintenance) and CP 443-1 Manual Chapter 7.3. A newer physical module can be installed directly into the rack without upgrading the engineering software or forcing unsupported catalog updates, provided it is configured as the released predecessor module.

Compatibility Matrix: CP 443-1 EX30 vs EX20 V2.0

The functional firmware of the CP 443-1 EX30 recognizes configurations compiled for earlier modules:

Hardware Actually Installed: 6GK7443-1EX30-0XE0 (CP 443-1 EX30 with dual-port ERTEC 400 switch).
Configured Hardware in HW Config: 6GK7443-1EX20-0XE0 (Version V2.0 or V1.0).
Operational Status: When the S7-400 CPU boots, it transfers the EX20 parameter record to the EX30 hardware. The EX30 accepts the parameter record, starts up normally, and sets its RUN LED solid green without generating an external fault (EXTF) or hardware mismatch diagnostic alarm.

Step-by-Step Replacement and Configuration Workflow

Follow this engineering procedure to add or replace the communications processor:

Configure in HW Config:
- Open the S7-400 station in STEP 7 HW Config in PCS 7 V7.1 SP2.
- From the hardware catalog, select SIMATIC 400 > CP 443-1 > 6GK7443-1EX20-0XE0 > V2.0.
- Insert the module into an open rack slot (e.g. Slot 4 or Slot 5).
- Assign the required IP address, subnet mask, and connect it to the Industrial Ethernet plant bus subnet.
Configure S7 Connections in NetPro:
- Open NetPro and configure S7 connections or Named Connections to the OS Servers.
- Execute Save and Compile in NetPro.
Physical Hardware Installation:
- Power down the rack (or use hot-swap in UR2-H subracks if supported by the rack backplane).
- Insert the physical 6GK7443-1EX30-0XE0 module into the selected slot.
- Connect the Industrial Ethernet patch cable to Port 1 or Port 2.
Download Configuration: Energize the rack and download HW Config and NetPro to the controller.

Functional Constraints Operating in Compatibility Mode

While compatibility mode guarantees stable communication, operation is strictly bounded by the predecessor profile:

Active Capabilities: Standard S7 communication, S7 routing, SEND/RECEIVE interfaces, ISO-on-TCP (RFC 1006), and SIMATIC time-of-day synchronization function identically to an EX20.
Suppressed EX30 Features: Advanced EX30 capabilities such as expanded connection limits (exceeding 64 connections), integrated web server diagnostics, IP access protection lists (firewall filtering), and advanced SNMP MIB variables are unavailable because the offline STEP 7 parameter blocks do not generate the requisite initialization telegrams.

Hardware Feature Comparison: EX20 vs EX30

The table below contrasts physical and functional characteristics of both generations:

Hardware ParameterCP 443-1 EX20 (Predecessor)CP 443-1 EX30 (Successor)Operating in Compatibility ModeSiemens Order Number (MLFB)6GK7443-1EX20-0XE06GK7443-1EX30-0XE0Hardware: EX30 / Config: EX20Integrated Switch Ports2 x RJ45 (10/100 Mbit/s)2 x RJ45 (10/100 Mbit/s)2 x RJ45 fully functionalMax S7 ConnectionsUp to 64Up to 128Constrained to 64 connectionsPROFINET IO ControllerSupported (RT)Supported (RT / IRT)Operates according to EX20 profileWeb Server DiagnosticsBasicAdvanced HTTP/HTTPSInactive / Basic responsePCS 7 V7.1 SP2 Release StatusNative catalog entrySpare part replacementOfficially supported via compatibility mode

Verification

Confirm that the CP 443-1 EX30 operates cleanly in compatibility mode:

Observe the front LEDs of the CP 443-1: verify RUN is solid green and STOP, INTF, and EXTF are off.
In SIMATIC Manager, open PLC > Diagnostic/Setting > Module Information for the CP.
Verify that the diagnostic buffer reports Module operational and displays no firmware incompatibility faults.
In WinCC OS Runtime, verify that S7 Named Connections established through the new CP show status OK in WinCCChnDiag.exe.
Execute an ICMP ping from an external engineering laptop to the CP IP address; verify consistent <1 ms round-trip response.

Limitations and Operational Precautions

Observe the following safeguards when deploying replacement hardware:

Do Not Force Unofficial HSPs: Avoid installing unofficial or unverified Hardware Support Packages (HSP) into PCS 7 V7.1 SP2 to force the EX30 catalog entry, as this can destabilize project compilation and OS compilation scripts.
Redundant System Matching: In redundant AS 400H subracks, it is best practice to maintain identical CP models across both partner racks to ensure symmetric network timing.
Commercial Procurement Guardrail: Sizing communication capacity requires verifying exact MLFBs (6GK7443-1EX30-0XE0) against authorized distributor schedules before procuring replacement spare modules.

Engineer FAQ

Will the S7-400 CPU go to STOP if I insert a CP 443-1 EX30 configured as an EX20?

No. The CP 443-1 EX30 firmware is specifically designed to recognize and accept the configuration data block of the CP 443-1 EX20 V2.0 without triggering an external fault or stopping the CPU.

Can I use the second RJ45 port on the CP 443-1 EX30 when configured as EX20?

Yes. Both physical ports on the integrated real-time switch operate normally for line or star topologies, as the EX20 also featured a dual-port switch.

Can I configure the EX30 for 128 S7 connections in PCS 7 V7.1 SP2?

No. Because the module is configured as an EX20 V2.0 in the offline project, the STEP 7 NetPro compiler enforces the 64-connection limit of the EX20 profile.