Interpret the PSuite Compiler Message
In PSuite 4.2.1.8, the reported compile failure opened the CPU Hardware Configuration form when the Location button was clicked instead of navigating to a ladder rung. This left the affected rung unidentified in a large project. The available evidence does not establish whether this navigation behavior affects every project or is limited to this project.
Do not assume that “Tag missing in instruction” always identifies an undeclared tag. A deliberately created error produced Problem Report entries containing the rung, column, and task, such as “rung 1 column 1” and “New Task.” If those fields are absent, treat the report as incomplete and use the two inspection paths below.
Separate the Two Possible Fault Conditions
| Condition | Evidence | Inspection target |
|---|---|---|
| Instruction has no tag operand | A deliberately created project reported “Tag missing in instruction” with rung, column, and task locations. | Instructions containing a blank or missing tag field. |
| Boolean flag is written but never read | The reported project compiled after locating an OUT coil whose Boolean flag tag was not used anywhere as a contact input. | OUT coils and whether each destination flag is referenced by a contact. |
The second condition resolved this specific case, but the evidence does not prove that PSuite 4.2.1.8 universally rejects every write-only Boolean flag. Treat it as an observed compiler condition, not a documented product rule.
Locate the Error in a Large Project
- Read the complete Problem Report entry. If it includes a task, rung, and column, navigate directly to that location instead of relying on the Location button.
- If the report omits the rung details, search ladder instructions for an empty tag operand. This is the direct interpretation of “Tag missing in instruction.”
- Review OUT coils that write Boolean flag tags. For each one, determine whether the same flag is used as a contact input anywhere in the project.
- Correct the identified rung and compile again. Confirm that the original report entry disappears and check whether any additional errors remain.
Escalate an Incomplete Compiler Report
If the error remains and the report still provides no task, rung, column, or tag, preserve a project version that reliably reproduces the failure. Submit that reproducible project through the product’s official technical-support channel for QA review. Include the PSuite 4.2.1.8 version and describe that the Location button opens CPU Hardware Configuration rather than the affected rung.
FAQ
Why does PSuite 4.2.1.8 open CPU Hardware Configuration for a compiler error?
That behavior was observed in the reported project, but its cause is not established by the evidence. Use any task, rung, and column data in the Problem Report; if those fields are missing, inspect blank instruction operands and write-only OUT flags.
What does “Tag missing in instruction” mean in PSuite?
It can indicate an instruction with no tag operand. In the resolved case, however, the implicated rung contained an OUT coil for a Boolean flag that was not used anywhere as a contact input.
How do I verify that I found the PSuite compiler error?
Correct the suspected rung and compile the project again. Verification is complete when the original Problem Report entry disappears; if it remains without location details, retain a reproducible project for technical-support and QA review.
