{"schemaVersion":1,"slug":"carrier-transmit-enable-input","name":"Carrier transmit-enable input","kind":"symbol","abbreviation":"CTI","aliases":["Line carrier and protection communication interfaces","switchyards Line carrier and protection communication interfaces","switchyards","Switchyards","Protection communication initiation","Carrier transmit request"],"category":"power-distribution","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Identifies the selected protection condition that permits carrier transmission.","description":["Identifies the selected protection condition that permits carrier transmission. 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 “Protection communication initiation” at the input and “Carrier transmit request” at the output. The receiving scheme defines the message meaning.","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: Protection communication initiation. Identify its source device or document and the state represented on the drawing.","Follow the named output: Carrier transmit request. Cross-reference its destination and separate the command from confirmation that the equipment responded.","The receiving scheme defines the message meaning.","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 protection communication initiation.","Identify the destination and defined state of carrier transmit request.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: The receiving scheme defines the message meaning."],"distinction":"The receiving scheme defines the message meaning. 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":"Protection communication initiation"},{"label":"Output / connection","value":"Carrier transmit request"},{"label":"Lookup label","value":"CTI 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-receive-detection-output"],"artwork":"pi26-carrier-transmit-enable-input","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchyards","family":"line-communications","input":"Protection communication initiation","output":"Carrier transmit request"},"plainEnglish":{"title":"What this block does","introduction":"Identifies the selected protection condition that permits carrier transmission.","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 “Protection communication initiation” at the input and “Carrier transmit request” at the output. The receiving scheme defines the message meaning.","drawings":"Start at the named input: Protection communication initiation. Identify its source device or document and the state represented on the drawing. Follow the named output: Carrier transmit request. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Protection communication initiation"},{"name":"Output","meaning":"Carrier transmit request"},{"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":["Protection communication initiation","CTI","Carrier transmit request"],"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-transmit-enable-input","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/carrier-transmit-enable-input.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."}]}