{"schemaVersion":1,"slug":"station-telemetry-stale-data-flag","name":"Station telemetry stale-data flag","kind":"symbol","abbreviation":"STSF","aliases":["Substation automation and command interfaces","substations Substation automation and command interfaces","substations","Substations","Data age and quality","Stale information flag"],"category":"measurement-protection","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Indicates that a measurement or status has exceeded its defined freshness condition.","description":["Indicates that a measurement or status has exceeded its defined freshness condition. Station automation collects measurements and statuses and issues assigned commands through defined authority paths. A communicated point has a value, quality and equipment identity; it should not be treated as an unexplained contact.","In a substation control building, the station controller receives bay information and forwards an operator's selected command to the correct bay device. Device feedback confirms whether the intended result actually occurred. For this reference, the drawing identifies “Data age and quality” at the input and “Stale information flag” at the output. Stale data must remain distinguishable from a current value.","Document the point mapping, source, destination, command authority and failure behavior. A communication interface block explains information flow and does not certify network security or control-system availability. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation."],"readingNotes":["Start at the named input: Data age and quality. Identify its source device or document and the state represented on the drawing.","Follow the named output: Stale information flag. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Stale data must remain distinguishable from a current value.","Document the point mapping, source, destination, command authority and failure behavior. A communication interface block explains information flow and does not certify network security or control-system availability."],"drawingChecklist":["Label the source and connection reference for data age and quality.","Identify the destination and defined state of stale information flag.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Stale data must remain distinguishable from a current value."],"distinction":"Stale data must remain distinguishable from a current value. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.","facts":[{"label":"Representation","value":"Functional block"},{"label":"Installation focus","value":"Substations"},{"label":"Input / boundary","value":"Data age and quality"},{"label":"Output / connection","value":"Stale information flag"},{"label":"Lookup label","value":"STSF is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-station-automation","relevance":"Public technical context for substation automation and command interfaces. Station I/O, alarms, event recording, command and communications interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["ga-substation-rtu","plc-digital-input","station-analogue-scaling-interface"],"artwork":"pi26-station-telemetry-stale-data-flag","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"substations","family":"station-automation","input":"Data age and quality","output":"Stale information flag"},"plainEnglish":{"title":"What this block does","introduction":"Indicates that a measurement or status has exceeded its defined freshness condition.","example":"In a substation control building, the station controller receives bay information and forwards an operator's selected command to the correct bay device. Device feedback confirms whether the intended result actually occurred. For this reference, the drawing identifies “Data age and quality” at the input and “Stale information flag” at the output. Stale data must remain distinguishable from a current value.","drawings":"Start at the named input: Data age and quality. Identify its source device or document and the state represented on the drawing. Follow the named output: Stale information flag. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Data age and quality"},{"name":"Output","meaning":"Stale information flag"},{"name":"Application reference","meaning":"An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections."}],"diagram":"flow","steps":["Data age and quality","STSF","Stale information flag"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"SEL-2411 programmable automation controller","url":"https://selinc.com/products/2411/"}],"profileId":"power-installation-station-automation"},"url":"https://eloragrid.ai/symbols/station-telemetry-stale-data-flag","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/station-telemetry-stale-data-flag.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-station-automation","publisher":"SEL","title":"SEL-2411 programmable automation controller","url":"https://selinc.com/products/2411/","scope":"Station I/O, alarms, event recording, command and communications interfaces.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for substation automation and command interfaces. Station I/O, alarms, event recording, command and communications interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}