{"schemaVersion":1,"slug":"iec-interconnection-dependency-z","name":"IEC interconnection dependency (Z)","kind":"symbol","abbreviation":"Zm","aliases":["Z dependency","internal interconnection dependency","Zm label"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"Dependency label Zm showing an internal connection from one point of a symbol to every terminal labelled m.","description":["Z dependency states that the affecting input or output is internally connected to every input or output labelled with the same number, which then takes its logic state. It lets a symbol show internal wiring without drawing it, for example an internal output that drives several internal inputs.","On device symbols, Z dependency often explains why an output appears to have the same state as an internal signal or why a pin also acts on another function. Drafters reproducing such symbols should keep the labels together.","Z dependency indicates logic state transfer only. It does not imply the connection is externally accessible or measurable."],"readingNotes":["Trace each Zm to every terminal labelled m.","Z labels describe internal connections, not external wiring."],"drawingChecklist":["Label the source as Zm.","Mark each connected terminal with m.","Do not use Z labels to stand in for external wiring."],"distinction":"X (transmission) dependency describes a bidirectional switch path controlled by the affecting input; Z is a fixed logical connection.","facts":[{"label":"Meaning","value":"Internal logic connection"},{"label":"Typical use","value":"Internal outputs feeding several functions"},{"label":"Artwork scope","value":"Original educational illustration; consult the applicable standard and the selected device documentation for the exact graphic"}],"references":[{"sourceId":"s28-ti-ieee91-logic-symbols","relevance":"Z (interconnection) dependency description."}],"related":["iec-and-dependency-g","iec-control-dependency-c","iec-common-control-block"],"artwork":"s28-iec-interconnection-dependency-z","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Output or internal output labelled Zm with affected terminals labelled m","reference":"Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier."},"plainEnglish":{"title":"What does IEC interconnection dependency (Z) mean?","introduction":"Z dependency states that the affecting input or output is internally connected to every input or output labelled with the same number, which then takes its logic state. It lets a symbol show internal wiring without drawing it, for example an internal output that drives several internal inputs.","example":"On device symbols, Z dependency often explains why an output appears to have the same state as an internal signal or why a pin also acts on another function. Drafters reproducing such symbols should keep the labels together.","drawings":"Z dependency indicates logic state transfer only. It does not imply the connection is externally accessible or measurable.","terms":[{"name":"Terminal","meaning":"An identified point where a conductor connects."},{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"name":"Schematic","meaning":"A drawing showing function and connections rather than physical appearance."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf"}],"detail":"Dependency label Zm showing an internal connection from one point of a symbol to every terminal labelled m. X (transmission) dependency describes a bidirectional switch path controlled by the affecting input; Z is a fixed logical connection.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-interconnection-dependency-z","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-interconnection-dependency-z.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"s28-ti-ieee91-logic-symbols","title":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","publisher":"Texas Instruments","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf","type":"manufacturer","scope":"Public explanation of rectangular logic symbols, general qualifiers, input and output qualifiers, dependency notation, bistable elements and coders, consistent with IEC 617-12 work.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"Z (interconnection) dependency description."}]}