Enable SubsPV_In on PCS 7 Pcs7AnIn with Feature Bit 29
For the reported PCS 7 V9.1 project, assemble the Feature structure with the required Boolean at bit 29 and connect that structure to the Pcs7AnIn block. Siemens' APL documentation includes StrctCom, a structure composer for 32-bit structures; it provides a way to build a Feature structure when an individual structure element is not exposed as a directly interconnectable pin. Confirm the exact bit assignment in the installed APL manual before enabling substitution behavior.
Table of Contents
- Build the Feature structure
- Set only the required behavior
- Verify substitution and quality
- Verification
- Limitations and Operational Precautions
- Technical References
- Related Articles
- Related Tags
- Engineer FAQ
Build the Feature structure
Insert the APL StrctCom block and configure the Boolean input corresponding to Feature bit 29. Connect the composer's output structure to the Feature input of Pcs7AnIn. The forum response describes StrctCom as forming a structure type output with 32 binary elements, such as the Feature input.
Set only the required behavior
Set bit 29 only if the installed Pcs7AnIn block manual confirms that it enables SubsPV_In as the output value for a bad process value. Leave other feature bits at their intended defaults or explicitly configured values; an incorrectly composed structure can enable unrelated block behavior.
Verify substitution and quality
In an approved test environment, simulate or create a controlled invalid PV condition and verify that the block output follows SubsPV_In when the feature is enabled. Also confirm that the bad-quality condition remains visible through the block's diagnostic/status outputs; a substitute value must not conceal the fact that the measured PV is invalid.
Verification
Check the StrctCom input and output values online, confirm the target Feature structure is connected, and verify behavior for both good and bad PV states. Review the compiled chart and block instance to ensure the tested project matches the deployed project.
Limitations and Operational Precautions
The source is PCS 7 V9.1 but does not identify the exact APL revision or provide the attachment screenshot. Feature-bit assignments are block/version-specific. Do not assume that the same bit has the same behavior in another block or APL release.
Technical References
- Siemens, Advanced Process Library V9.1 SP1 Function Manual, sections 15.9–15.10,
StrctComandStrctDeC: https://support.industry.siemens.com/cs/attachments/109805402/s7jal91b_en-US.pdf
Related Articles
Related Tags
Engineer FAQ
How can I set Feature bit 29 on Pcs7AnIn? Use the PCS 7 APL structure composer (StrctCom) to assemble the required Boolean feature fields and connect the resulting structure to the block's Feature input.
What does Feature bit 29 do? The source identifies bit 29 as enabling SubsPV_In as the output value when the process value is bad; confirm that assignment in the installed APL version manual.
Why cannot I interconnect Feature.Bit29 directly? Feature is a structure input; use structure-compatible blocks or instance parameterization instead of treating it as a scalar Boolean pin.
What is StrctCom? The APL manual describes StrctCom as a structure composer for 32-bit structures.
Must all 32 feature bits be separately wired? No. Configure only required bits and set the rest to documented/default values; ensure no unintended bit is enabled.
Can I change the bit in test mode? The forum reports instance-specific changes during test mode; follow PCS 7 engineering permissions and operational controls for the actual installation.
What does SubsPV_In substitute? The ticket describes it as a substitution value for a bad PV; verify the exact fallback behavior and feature semantics in the APL V9.1 block manual.
Can a structure decomposer be used? StrctDeC extracts structure fields; the question concerns forming the Feature structure, for which StrctCom is the relevant block.
How do I test the feature? In an approved test, create a bad PV condition and confirm output behavior uses the configured substitution value without masking the bad-quality state.
Does this apply to every APL version? The source is PCS 7 V9.1; verify bit assignments and structure block availability in the installed APL release.