How to Inspect an SFC Type Timer Preset and Remaining Time
For an SFC type's internal timer, inspect the configured preset and remaining-time I/Os on the actual SFC instance rather than relying on the step run-time display. In SFC for SIMATIC S7 V9.0, TIME0 is the time in seconds and PTIME is time remaining. The manual provides a CFC test-mode inspection route; a specific procedure showing both values directly in the requested transition dialog is not established for the unspecified release.
Table of Contents
- Use the Internal Timer Characteristic
- Inspect the Instance in CFC Test Mode
- Transition Evaluation Is a Separate Question
- Verification
- Limitations and Operational Precautions
- Engineer FAQ
- Technical References
- Related Articles
- Related Tags
Use the Internal Timer Characteristic
The question concerns an internal SFC type timer started in one step, with a five-minute duration, and asks to see its configured and actual time in a transition. That is distinct from the step's Minimum and Maximum run-time settings.
For the documented SFC V9.0 timer characteristic, the interface includes <name>_TIME0 for the time in seconds and <name>_PTIME for time remaining. Replace <name> with the actual configured timer name; the brackets are explanatory notation, not part of an I/O identifier.
Inspect the Instance in CFC Test Mode
The SFC V9.0 manual, chapter 17, documents access to timer-characteristic I/Os at the SFC instance in CFC test mode. Use that as the verified inspection route:
- Identify the intended SFC instance and the timer characteristic's exact configured name.
- Establish an approved test context and open the instance in CFC test mode.
- Locate the corresponding TIME0 and PTIME I/Os and inspect their values.
- Inspect the timer mode, start/reset signals and QERR indication when interpreting those values.
- Observe the intended timer sequence without writing parameters merely to make a value visible.
The table defines a five-minute preset as 300 seconds by unit conversion. That does not demonstrate which preset the running instance actually uses.
Transition Evaluation Is a Separate Question
The manufacturer's characteristic description allows timer use across steps and querying timed behavior in transitions. This does not independently establish that the transition dialog automatically shows a preset, elapsed and remaining-time display.
The precise requested transition display procedure remains unresolved for the unidentified installed release. The reply's claim that timer information is available only in steps is too broad to use as a universal rule: the documented instance I/O inspection route also exists.
Do not rename PTIME as elapsed time. A derived elapsed display would require a separately reviewed implementation and validation of the timer's start, reset, mode and preset behavior.
Verification
Confirm the instance identity and actual timer name before interpreting the values. Under approved test conditions, record the preset, remaining time and relevant start/reset state through the intended sequence.
Compare observations after reset and after the timer's intended completion. Check the transition condition independently from visibility of the timer values. Observing a changing remaining-time value alone does not prove that the transition implements the required process logic.
Limitations and Operational Precautions
The installed SFC release and referenced screenshot are unavailable. The article supplies a V9.0 manufacturer-documented interface and inspection baseline; exact transition-dialog display behavior remains to be established.
CFC test access can involve a running controller. Preserve the project baseline and use an approved context; do not force signals, reset a live process timer or change the preset simply to investigate its display.
Engineer FAQ
Is PTIME elapsed time?
The documented meaning is time remaining in seconds.
Is the step's Maximum run time the same object?
No. The question concerns a timer characteristic started within the sequence.
Is a preset-and-actual transition display procedure verified?
Not for the unspecified installed release.
Technical References
- Siemens: SFC for SIMATIC S7 V9.0, May 2017, A5E41356228-AA — chapter 11, characteristic overview; section 13.2.6.8, timer I/Os; chapter 17, inspection of instance characteristics in CFC test mode.