How to Re-enable a CFC Runtime Group for Online Monitoring

If CFC Test mode is enabled but block values are unavailable online, first check whether the chart's runtime group is switched on in the CFC Runtime Editor. In the reported case, the suggested correction was to open the Runtime Editor from a block's runtime-group indicator, locate the CFC, and select “Switch on Runtime Group.” Confirm the exact CFC/PCS 7 release and runtime-group state before applying the operation; the ticket's screenshots and error details are unavailable.

What the symptom indicates

The source reports that Test mode was enabled for a downloaded CFC while the CPU was in RUN, but block input/output values were not visible online and an unreadable error appeared. A reply suggested that the chart was deactivated in the Runtime Editor. The visible evidence is insufficient to determine whether that was the actual cause; treat runtime-group state as the first targeted check, not a proven diagnosis.

Check the chart's runtime group

In the CFC chart, locate the block's runtime-group indicator as presented in the installed editor version.
Open the Runtime Editor using the version-specific editor action for that indicator.
Locate the relevant CFC/chart in the runtime structure and inspect whether its runtime group is active.
If the group is inactive and the project design requires it to execute, use the editor's “Switch on Runtime Group” command.
Return to the chart's online view and verify the intended block values. If the group is already active, do not toggle unrelated groups; capture the exact diagnostic and inspect the download, communication and online-monitoring conditions instead.

Understand the scope of the change

CFC runtime groups control execution/runtime organization. Siemens CFC documentation distinguishes runtime-group management and notes that activation/deactivation applies to specified groups in the run sequence. A change can affect controller execution, so do not enable groups indiscriminately or treat an online display issue as permission to alter control logic. Use the manual matching the project's CFC version.

Expected observations

After the relevant group is active and the online connection is valid, the intended CFC block should be available for the editor's online observation function. This does not prove that every block is executing correctly or that the process value is valid; verify the value path and controller state separately.

If switching on does not restore values

Record the exact error message at readable resolution. Confirm the correct CPU/project is selected, the chart was compiled/downloaded as required for the installed version, and the online interface reaches the intended CPU. Check whether the relevant chart/group is present in the run sequence. Avoid online changes or downloads to a production controller until their effect and authorization are understood.

Verification

Confirm the group state in the Runtime Editor, establish online connection to the intended CPU, and observe a known noncritical block input/output whose source value is independently understood. If observation remains unavailable, retain the error text and version information for a targeted diagnosis rather than repeating runtime-group toggles.

Limitations and Operational Precautions

The ticket omits the CFC and PCS 7 versions and the error text; attached screenshots are not available in the text. The “Switch on Runtime Group” action comes from the reported reply. Siemens' CFC V9.0 SP2 manual discusses runtime structures and group state, but exact wording and editor steps should be checked against the installed release. Changing a runtime group can affect execution; use project review and site change control.

Engineer FAQ

Where is runtime-group state inspected? In the CFC Runtime Editor/run sequence for the applicable project version; use the chart's runtime-group indicator to navigate if that behavior matches the installed editor.

Should all groups be switched on? No. Only change the group identified as inactive and required by the control design.

Does enabling a group prove the controller values are correct? No. It only addresses the specific group state; verify the intended block values and signal path.

What if the group is already active? Preserve the exact error, verify the CPU/project/interface and chart runtime assignment, then investigate the actual diagnostic.

Is the source diagnosis confirmed? No. The source's error screenshot is unreadable and the reply proposed checking a deactivated chart.

Technical References

Siemens, CFC for SIMATIC S7 V9.0 SP2 Function Manual, section 10.11 “Defining runtime properties”: https://support.industry.siemens.com/cs/attachments/109759209/s7cfcs7b_en-US.pdf