Understand Textual Interconnections for PCS 7 SFC Outputs
A textual interconnection in an SFC chart is not automatically an error. Siemens documentation describes it as a path reference to a CFC block input or output when the actual connection partner is not yet available or is referenced across charts. For the STOPPING output, confirm that the textual path points to the intended SFC output and that the partner resolves; a compile-only change does not prove the reference is valid.
Table of Contents
- Why the editor displays a text reference
- Check whether the partner is resolved
- Validate the selected STOPPING signal
- Compile and verify
- Limitations and Operational Precautions
- Technical References
- Related Articles
- Related Tags
- Verification
- Engineer FAQ
Why the editor displays a text reference
PCS 7 SFC charts can use textual interconnections as path references to block inputs or outputs in CFC. The editor may display the reference as text instead of a graphical wire. Siemens documentation describes this as normal when the connection partner is not yet available.
Check whether the partner is resolved
Inspect the SFC chart sheet bar and compile messages. Siemens documentation states that an unresolved textual reference is indicated by a yellow triangle; when its actual partner becomes available, the reference is replaced by a real interconnection. Confirm the target chart, block, and STOPPING output are the intended ones.
Validate the selected STOPPING signal
Use the SFC/CFC browser to select the correct output where available, then verify the full path reference after applying the dialog. Check that the output belongs to the intended SFC chart instance and is not a similarly named signal from another chart.
Compile and verify
Update/compile the affected project objects and check whether the partner resolves. If the text remains, inspect project refresh state and the path reference rather than repeatedly compiling changes without checking the link target.
Limitations and Operational Precautions
The ticket does not give the PCS 7 version, exact path text, compile messages, or sheet-bar marker. Textual links are valid only when the path points to the intended partner; unresolved references must not be assumed correct or loaded into a production AS.
Technical References
- Siemens, PCS 7 SMART Getting Started Part 2 V8.2, section 6.3, textual interconnections in SFC charts: https://support.industry.siemens.com/cs/attachments/109478795/ps7gs2_b_en-US.pdf
- Siemens, CFC for SIMATIC S7 V9.0 SP5 Function Manual, AS-wide and chart interconnection behavior: https://support.industry.siemens.com/cs/attachments/109782631/s7cfcs7b_en-US.pdf
Related Articles
Related Tags
Verification
Verify configuration and observable runtime behavior against the intended process requirements.
Engineer FAQ
Is a textual interconnection in an SFC necessarily an error? No. Siemens documentation describes it as a path reference when the corresponding CFC connection partner is not yet available.
What does a yellow triangle on the SFC sheet bar mean? It indicates the textual interconnection has no resolved actual partner yet.
Can the textual reference be valid after Apply? Yes, if the path points to the intended block input or output and the partner becomes available; verify resolution after project update/compile.
Why does the SFC STOPPING output appear as text? SFC textual interconnections use path references to CFC block I/Os; the graphical representation can therefore be textual rather than a drawn wire.
Does compile-only-change replace the text? Compilation alone does not establish that the reference resolves; verify the actual interconnection partner and sheet-bar status.
How do I enter a valid path? Use the path-reference format shown by the SFC/CFC editor or select the I/O from the browser; exact syntax depends on the chart and version.
Can an unresolved textual link be downloaded? Do not assume so; resolve missing partners and inspect compile warnings before loading.
What if the partner exists but the link remains textual? Check project refresh/update state, chart identity and connection path, then re-open the chart and compile as required by the installed release.
Can SFC output signals be linked across charts? They can be linked through supported CFC/SFC interfaces; follow the manual's rules for SFC chart I/Os.
What version applies? The ticket does not state PCS 7 version; verify behavior in that release's CFC/SFC manual.