Resolving ET200SP F-DI F_Source_Add Error in STEP 7 V5.6

1. Problem Overview

An ET200SP distributed I/O station equipped with fail-safe digital input (F-DI) and fail-safe digital output (F-DO) modules reports F_Source_Add and parameter-mismatch diagnostics on every power-up or download cycle. The F-CPU goes into STOP with an SF (Group Fault) LED, the F-module's DIAG LED flashes red, and every channel-status LED on the F-DI and F-DO modules lights steady red. The F-runtime group compiles clean in the Safety Program Editor, and the project downloads to the F-CPU without a consistency error, yet the safety peripherals refuse to go to RUN.

This symptom is specific to STEP 7 V5.6 (or earlier SIMATIC Manager) projects that integrate ET200SP fail-safe modules through a GSD file rather than through the hardware catalog (HSP). The F-CPU cannot derive the F-source address and the safety-relevant parameters from a plain GSD slot, so the F-modules reject the configuration as invalid.

2. Affected Components and Versions

3. Observed Diagnostic Indicators

When the F-CPU or the F-host (PROFINET IO controller) detects an invalid PROFIsafe configuration, the following indicators are visible in the field:

• SF LED on the F-CPU – solid red, signalling a safety-relevant fault that has placed the F-runtime group in a fail-safe state.
• DIAG LED on the F-DI / F-DO module – flashing red (2 Hz) per the SIMATIC ET 200SP system manual, indicating "module diagnostics pending".
• Channel Status LEDs – all input or output channels show steady red, indicating the channel is in the passivated state.
• Diagnostic buffer entry on the F-module – "Parameter assignment error" combined with channel diagnostics "F_Source_Add incorrect" or "Safety parameter assignment error".
• PROFIsafe channel error – the F-host reports CRC errors or "communication disturbed" because the F-module rejects the F-parameter telegram with an invalid source address.

Per the SIMATIC ET 200AL fail-safe module manual, the same diagnostic class ("Communication between F-CPU and F-module is disturbed", "F-monitoring time is set") applies to ET200SP F-modules: the firmware on the F-module detects a CRC error in the PROFIsafe telegram and passes the channel into the safe state.

4. Root Cause Analysis

The root cause is the configuration path used to insert the ET200SP fail-safe modules into HW Config. STEP 7 V5.6 SP HF3 supports two ways of placing an ET200SP device in the PROFINET topology:

1. Hardware catalog (HSP) entry – modules are dragged from the SIMATIC ET200SP folder under "PROFINET IO -> I/O -> ET200SP". In this case, STEP 7 already knows the F-parameter record layout and the slot-level F-source address assignment dialog is available directly in HW Config.
2. GSD-based entry – the user installs the GSDML of the ET200SP head module and slots the F-DI / F-DO via the GSD. The plain GSD does not carry the safety record descriptions, so STEP 7 cannot generate the F_iPar_CRC. The F-modules boot, receive a generic PROFINET parameter record, and immediately flag the safety slot with F_Source_Add invalid because the host has not pushed a valid F-source-address record to slot 0 of the module.

Because the F-runtime group compiles correctly and the F-CPU program downloads, the engineer is led to believe the safety configuration is sound. The error is not in the F-runtime group or in the S7 Distributed Safety signature; it is in the PROFINET slot configuration of the F-DI and F-DO that precedes the safety program download. The PROFIsafe host (F-CPU 6ES7151-8FB01-0AB0 acting as a lower-level F-host in this case) cannot inject F-parameters into modules it does not know about as safety modules.

5. Solution Path A – Use S7-FCT with a GSD-Configured Head Module

If the ET200SP station is already projected via the GSDML (common when the STEP 7 HSP does not yet contain the latest head-module firmware), Siemens ships a separate tool: S7-Fail-safe Configuration Tool (S7-FCT). This tool injects the F-source address, the F-monitoring time, the F-iPar-CRC, and the slot-level F-parameter record into the GSD-projected module.

5.1 Install S7-FCT

1. Obtain the latest S7-FCT from the Siemens support portal (entry ID 109751706 – "SIMATIC S7 Failsafe Configuration Tool").
2. Install S7-FCT on the same engineering station that hosts STEP 7 V5.6 HF3 and S7 Distributed Safety V5.4 SP5.
3. Restart SIMATIC Manager; the S7-FCT COM server registers automatically.

5.2 Assign the F-Source Address

1. Open the SIMATIC Manager project and double-click HW Config.
2. Right-click the F-DI module slot (6ES7136-6BA00-0CA0) and select Device-Tool > S7-FCT (this entry is added by the S7-FCT installation).
3. In the S7-FCT dialog, enter the F-Source-Address. The post specifies the base PROFIsafe address is 2000; in the F-DI slot the source address field therefore reads 2000, and on the F-DO slot it is incremented to 2001 (one PROFIsafe address per F-slot).
4. Set the F-monitoring time. For ET200SP F-DI / F-DO modules on PROFINET, Siemens recommends 1000 ms to start; tighten to 100–300 ms only after establishing a stable PROFINET update cycle.
5. Repeat for the F-DO slot and download the S7-FCT data block alongside the HW Config download.

5.3 Recompile and Download

1. In HW Config, select Station > Save and Compile.
2. Download the HW Config to the ET200S F-CPU.
3. Open the Safety Program Editor, recompile the F-runtime group, and download the safety program to the F-CPU.
4. Cycle power on the ET200SP station to force the F-modules to re-read the F-parameter record.

6. Solution Path B – Use the HW Catalog (HSP) Entry

If the head-module firmware revision is supported by an installed STEP 7 HSP, switch from the GSD to the native catalog entry. This path avoids S7-FCT entirely because HW Config natively generates the F-parameter record.

6.1 Install the Matching HSP

1. Identify the firmware version of the head module 6ES7155-6AU01-0CN0 (printed on the front of the module or read via the Web server).
2. From the Siemens support portal, download the matching HSP (for example, HSP 0263 for ET200SP, or any later HSP that supports the head-module firmware in use).
3. Run the HSP setup; it deposits the ET200SP device descriptions into the STEP 7 hardware catalog.

6.2 Replace the GSD Instance with the Catalog Instance

1. Open HW Config and delete the GSD-inserted head module and all submodules.
2. Drag the ET200SP head module from PROFINET IO > I/O > ET200SP to the PROFINET subnet.
3. Insert the F-DI (6ES7136-6BA00-0CA0) and F-DO (6ES7136-6DC00-0CA0) from the ET200SP catalog into the appropriate slots.
4. Double-click each F-module, navigate to the Safety tab, and enter the F-source address (2000 for the F-DI, 2001 for the F-DO).
5. Save, compile, and download HW Config.

Path B is the lower-risk route because it eliminates the GSD-to-S7-FCT handoff and produces a configuration that round-trips cleanly through STEP 7's built-in consistency checks.

7. PROFIsafe Address Configuration Reference

8. Verification Steps

1. LED check: After power-up, confirm the DIAG LED on each F-module is off (or solid green on modules with the green DIAG option). The channel-status LEDs should reflect the live input state, not steady red.
2. Diagnostic buffer on the F-CPU: Open PLC > Module Information > Diagnostic Buffer. There should be no "F_Source_Add" or "Parameter assignment error" entries after the initial start-up sequence.
3. Module information on the F-module: In HW Config online, right-click the F-DI/F-DO and select Module Information. The "F-Parameters" tab should display the source address 2000 (or 2001 for the F-DO) and the F-iPar-CRC as calculated by the host.
4. F-runtime group status: In the Safety Program Editor, verify the F-runtime group is in RUN and the F-CPU's SF LED is off.
5. Forced passivation test: Disconnect the PROFINET cable briefly to force a communication failure. The F-module should passivate its channels within the configured F-monitoring time. Reconnect and verify the module reintegrates (de-passivates) automatically once valid PROFIsafe telegrams resume.
6. Cross-check via Web server: The ET200SP head module's Web server ("Diagnostics > F-Parameters") shows the live F-source address of every F-slot – a quick sanity check that the host has actually pushed the parameter record.

9. Common Pitfalls and Edge Cases

• Mixing GSD and HSP on the same station. If only the head module is from the catalog and the F-modules are inserted via the GSD, the F-parameter mechanism still fails. Both the head and the F-slots must follow the same configuration path, or S7-FCT must be used to patch the GSD-inserted F-slots.
• Wrong S7-FCT version. An S7-FCT that pre-dates the F-module firmware revision may not know the parameter record layout and will generate an F-iPar-CRC of 0. The F-module boots, sees the zero CRC, and reports the parameter record as invalid. Always match S7-FCT revision to the module firmware.
• F-monitoring time too short for the PROFINET update time. If the F-host CPU is heavily loaded and the PROFINET IRT cycle drifts, the F-module can declare the host "disturbed" and passivate. Symptom looks like F_Source_Add error but is actually a watchdog trip.
• Shared PROFIsafe address on a shared device. ET200SP supports PROFIenergy and shared device operation. Sharing an F-slot between two IO controllers without coordinated F-parameter assignment will surface as a source-address conflict.
• PROFINET device name not assigned. Without a PROFINET device name the head module will not start PROFINET communication; the F-modules then report parameter assignment errors that look like F_Source_Add errors but are actually PROFINET AR (Application Relationship) failures.
• F-CPU in STOP while IO controller is in RUN. If a higher-level S7-300/S7-400 F-CPU is the IO controller and the lower-level ET200S F-CPU is in STOP, the ET200SP F-modules receive no F-parameter telegrams. The result is identical to a missing F-source address.

10. Diagnostic Message Reference

The following diagnostic messages are reported by the F-DI / F-DO firmware and are documented in the SIMATIC ET 200SP F-modules manual collection:

11. Migration Note – Successor Module 6ES7136-6BA01-0CA0

Plants that replace the original 6ES7136-6BA00-0CA0 with the current 6ES7136-6BA01-0CA0 gain MSI/MSO (modular safety input / output) capability, value status, and an updated parameter record layout. The F_Source_Add troubleshooting workflow is unchanged, but the S7-FCT or HSP must support the -0CA01 variant. The successor is functionally backward-compatible in the slot; the F-parameter records differ and require a fresh download of HW Config.

12. Related ET200SP Diagnostics to Verify First

Before assuming an F_Source_Add fault, rule out the four conditions that produce an identical LED pattern but are easier to fix:

1. PROFINET device name mismatch – assign the device name from HW Config (PLC > Ethernet > Assign PROFINET Device Name).
2. ET200SP head module not in RUN – the head module's RN/ER/MAINT LEDs will indicate a topology or configuration error; fix the head module first.
3. BaseUnit type mismatch – the F-DI requires a BU-type-A0 (light-colored base unit with feed-in); an F-DO on a type-C0 (dark base unit, no feed-in) will report a configuration error.
4. Firmware update incomplete – verify with the head module's Web server that all F-modules are at the firmware version declared in HW Config.

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