{"schemaVersion":1,"slug":"carrier-receive-detection-output","name":"Carrier receive-detection output","kind":"symbol","abbreviation":"CRO","aliases":["Line carrier and protection communication interfaces","switchyards Line carrier and protection communication interfaces","switchyards","Switchyards","Received carrier signal","Protection receive indication"],"category":"power-distribution","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Identifies the declared receive signal supplied by the selected carrier terminal.","description":["Identifies the declared receive signal supplied by the selected carrier terminal. A protection communication interface carries information between circuit ends or couples a communication signal to a primary line. Its signal path is different from the power-current path even when both use part of the same installation.","In a switchyard line bay, carrier-coupling equipment can connect a protection communication terminal to the transmission conductor. Fiber-based protection uses another physical path but still needs named endpoints and channel supervision. For this reference, the drawing identifies “Received carrier signal” at the input and “Protection receive indication” at the output. A receive indication is distinct from channel health.","Show each coupling boundary and the intended information direction. Frequency selection, channel performance, insulation duty and protective coordination require the selected communication and primary equipment design. 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: Received carrier signal. Identify its source device or document and the state represented on the drawing.","Follow the named output: Protection receive indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.","A receive indication is distinct from channel health.","Show each coupling boundary and the intended information direction. Frequency selection, channel performance, insulation duty and protective coordination require the selected communication and primary equipment design."],"drawingChecklist":["Label the source and connection reference for received carrier signal.","Identify the destination and defined state of protection receive indication.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: A receive indication is distinct from channel health."],"distinction":"A receive indication is distinct from channel health. 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":"Switchyards"},{"label":"Input / boundary","value":"Received carrier signal"},{"label":"Output / connection","value":"Protection receive indication"},{"label":"Lookup label","value":"CRO is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-carrier","relevance":"Public technical context for line carrier and protection communication interfaces. Line traps, coupling and power-line carrier communications. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["capacitor-voltage-transformer","85-pilot-or-carrier-receiver-relay","carrier-channel-supervision-alarm"],"artwork":"pi26-carrier-receive-detection-output","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchyards","family":"line-communications","input":"Received carrier signal","output":"Protection receive indication"},"plainEnglish":{"title":"What this block does","introduction":"Identifies the declared receive signal supplied by the selected carrier terminal.","example":"In a switchyard line bay, carrier-coupling equipment can connect a protection communication terminal to the transmission conductor. Fiber-based protection uses another physical path but still needs named endpoints and channel supervision. For this reference, the drawing identifies “Received carrier signal” at the input and “Protection receive indication” at the output. A receive indication is distinct from channel health.","drawings":"Start at the named input: Received carrier signal. Identify its source device or document and the state represented on the drawing. Follow the named output: Protection receive indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Received carrier signal"},{"name":"Output","meaning":"Protection receive indication"},{"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":["Received carrier signal","CRO","Protection receive indication"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Line traps: power-line carrier communication","url":"https://www.gevernova.com/grid-solutions/sites/default/files/2025-09/Line-Traps-Brochure-EN-N50059-Hybrid-202504-R002.pdf"}],"profileId":"power-installation-line-communications"},"url":"https://eloragrid.ai/symbols/carrier-receive-detection-output","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/carrier-receive-detection-output.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-carrier","publisher":"GE Vernova","title":"Line traps: power-line carrier communication","url":"https://www.gevernova.com/grid-solutions/sites/default/files/2025-09/Line-Traps-Brochure-EN-N50059-Hybrid-202504-R002.pdf","scope":"Line traps, coupling and power-line carrier communications.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for line carrier and protection communication interfaces. Line traps, coupling and power-line carrier communications. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}