Simulate a PCS 7 FbSwtMMS Block Without Masking Bad Quality
To simulate a PCS 7 channel block, use its documented simulation input and ensure the Mode parameter is configured for the selected channel mode. The PCS 7 APL V9.0 manual warns that an incorrect Mode during channel-block simulation can produce Bad = 1. Bad is a diagnostic output, so forcing it to zero is not a valid way to make simulation appear healthy; inspect the exact FbSwtMMS library revision and its diagnostic inputs if the status remains bad.
Table of Contents
- Set up the simulation inputs
- Configure Mode and diagnostics
- Keep library versions in scope
- Verification
- Limitations and Operational Precautions
- Technical References
- Related Articles
- Related Tags
- Engineer FAQ
Set up the simulation inputs
In CFC, enable the supported simulation input for the applicable block and supply the simulation value through its documented input. The APL V9.0 manual describes block simulation through SimOn and a corresponding simulation value input; confirm the exact input names on the installed FbSwtMMS block version.
Configure Mode and diagnostics
Check the channel block's Mode value against its hardware/channel configuration. Siemens specifically warns that an incorrect Mode during simulation can result in Bad = 1 with a higher-level error. Then inspect module/device diagnostics and input signal quality instead of overriding the Bad output.
Keep library versions in scope
FbSwtMMS is associated with the SIMOCODE pro PCS 7 library, whose release notes may include block changes. Record PCS 7, APL, SIMOCODE library, and PLCSIM versions and apply only the matching documented library update procedure.
Verification
In a controlled test project, confirm the simulation-active indication, intended simulated process value, Mode, diagnostic status, and Bad output. Confirm that process-related outputs show simulation status where expected and that simulation is disabled before returning the system to real I/O.
Limitations and Operational Precautions
The ticket gives no PCS 7 version, SIMOCODE library version, block inputs, or diagnostic state. The APL V9.0 manual supplies general channel-block simulation guidance but does not prove exact behavior for every FbSwtMMS release. Never suppress bad quality or treat simulation as a physical protection test.
Technical References
- Siemens, Advanced Process Library V9.0 Function Manual, section 2.1, block simulation and channel-block Mode: https://support.industry.siemens.com/cs/attachments/109482346/s7jal90b_en-US.pdf
- Siemens, SIMOCODE pro PCS 7 Library V9.0 SP2 Readme, block/library changes: https://support.industry.siemens.com/cs/attachments/109761334/MMReadme.pdf
Related Articles
Related Tags
Engineer FAQ
How do I simulate an FbSwtMMS channel block? Use the block's documented simulation inputs and set its Mode correctly; the PCS 7 APL V9.0 manual says incorrect Mode during channel-block simulation can produce Bad=1.
Does simulation require Bad to be zero? Not necessarily; Bad is a status output and may indicate invalid quality or other diagnostic errors. Never force it to zero just to suppress the indication.
What does SimOn control? The APL manual describes SimOn as enabling block simulation with a designated simulation value input.
Why is Mode important? APL documentation warns that a channel block's Mode must be set correctly during simulation or a higher-level error can appear at Bad.
Can a simulated value carry simulation quality? APL describes process-related outputs with simulation status; inspect the exact FbSwtMMS block and version behavior.
Is FbSwtMMS an APL block? It is a SIMOCODE pro channel block associated with PCS 7 libraries; exact library/version support matters.
What should I inspect if Bad stays high? Check SimOn, simulation value, Mode, diagnostics, block/library revision and exact source quality.
Does PLCSIM behave exactly like hardware? The source provides no simulator version or observed output values; compare with the block documentation and supported simulator setup.
Should I update the SIMOCODE library? Only according to the applicable PCS 7/SIMOCODE library release notes and migration guidance; block updates may change interfaces.
How do I confirm safe operation? Validate the simulated quality and downstream permissives in a non-production test; ensure simulation mode is visibly indicated and disabled before real operation.