{
  "node": {
    "id": "term:can-bus",
    "type": "Term",
    "label": "CAN bus",
    "properties": {
      "id": "can-bus",
      "name": "CAN bus",
      "aka": [
        "Controller Area Network",
        "ISO 11898"
      ],
      "section": "topic-pack",
      "definition": "The serial network over which a BMS talks to the vehicle or inverter: a two-wire differential bus, defined in ISO 11898, carrying short prioritised messages at up to 1 Mbit/s, or faster with CAN FD. Every node hears every message, and a dominant bit wins arbitration without any collision.",
      "related": [
        "can-high-low",
        "can-fd",
        "termination-resistor",
        "bms",
        "lin-bus",
        "fms-interface"
      ],
      "url": "https://lemonergy.com/learn/glossary/can-bus/",
      "mentions": [
        "inverter"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:2995",
      "source": "term:can-bus",
      "target": "topic:topic-pack",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:2996",
      "source": "term:can-bus",
      "target": "term:can-high-low",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2997",
      "source": "term:can-bus",
      "target": "term:can-fd",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2998",
      "source": "term:can-bus",
      "target": "term:termination-resistor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:2999",
      "source": "term:can-bus",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3000",
      "source": "term:can-bus",
      "target": "term:lin-bus",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:3001",
      "source": "term:can-bus",
      "target": "term:fms-interface",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/can-bus/inverter",
      "source": "term:can-bus",
      "target": "term:inverter",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:3003",
      "source": "term:can-bus",
      "target": "reference:cia-can",
      "type": "cites",
      "properties": {
        "sourceFile": "wiki-references.json",
        "scope": "direct technical reference"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-pack",
      "type": "Topic",
      "label": "Modules, packs and battery management",
      "properties": {
        "id": "topic-pack",
        "name": "Modules, packs and battery management",
        "lede": "From a single cell to a working battery system, and the electronics that keep it safe.",
        "context": "Make series/parallel architecture explicit.",
        "example": "Twelve 3.6 V, 5 Ah cells in 6s2p give 21.6 V, 10 Ah and 216 Wh nominally before other restrictions.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-architecture/",
        "lesson_label": "Open cell architecture"
      }
    },
    {
      "id": "term:can-high-low",
      "type": "Term",
      "label": "CAN high and CAN low",
      "properties": {
        "id": "can-high-low",
        "name": "CAN high and CAN low",
        "abbr": "CAN_H, CAN_L",
        "section": "topic-pack",
        "definition": "The two wires of a CAN bus, a twisted pair driven in opposite directions. Idle, or recessive, both sit near 2.5 V; for a dominant bit CAN_H is pulled up to about 3.5 V and CAN_L down to about 1.5 V, so the receiver reads the 2 V difference. Noise picked up by the pair adds equally to both wires and cancels in the difference.",
        "unit": "V",
        "related": [
          "can-bus",
          "termination-resistor",
          "can-fd"
        ],
        "url": "https://lemonergy.com/learn/glossary/can-high-low/",
        "mentions": []
      }
    },
    {
      "id": "term:can-fd",
      "type": "Term",
      "label": "CAN FD",
      "properties": {
        "id": "can-fd",
        "name": "CAN FD",
        "aka": [
          "CAN with flexible data rate"
        ],
        "section": "topic-pack",
        "definition": "An extension of classical CAN that switches to a higher bit rate, up to 5–8 Mbit/s, for the data part of each frame and allows 64 data bytes instead of 8. BMS data-logging and over-the-air updates are its usual battery uses.",
        "related": [
          "can-bus",
          "can-high-low",
          "bms"
        ],
        "url": "https://lemonergy.com/learn/glossary/can-fd/",
        "mentions": []
      }
    },
    {
      "id": "term:termination-resistor",
      "type": "Term",
      "label": "CAN termination",
      "properties": {
        "id": "termination-resistor",
        "name": "CAN termination",
        "aka": [
          "120 Ω termination"
        ],
        "section": "topic-pack",
        "definition": "A 120 Ω resistor between CAN_H and CAN_L at each end of the bus, matching the cable impedance so signals do not reflect. A healthy bus measures about 60 Ω between the two wires when powered down; 120 Ω means one terminator is missing.",
        "unit": "Ω",
        "related": [
          "can-bus",
          "can-high-low"
        ],
        "url": "https://lemonergy.com/learn/glossary/termination-resistor/",
        "mentions": [
          "impedance"
        ]
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "id": "term:lin-bus",
      "type": "Term",
      "label": "LIN bus",
      "properties": {
        "id": "lin-bus",
        "name": "LIN bus",
        "aka": [
          "Local Interconnect Network"
        ],
        "section": "topic-pack",
        "definition": "A cheap single-wire serial bus at up to 20 kbit/s with one master and several slaves, used where CAN is overkill: a smart 12 V battery sensor, a cooling fan or a heater controller reporting to the BMS.",
        "related": [
          "can-bus",
          "bms",
          "auxiliary-battery",
          "ldf"
        ],
        "url": "https://lemonergy.com/learn/glossary/lin-bus/",
        "mentions": []
      }
    },
    {
      "id": "term:fms-interface",
      "type": "Term",
      "label": "FMS interface",
      "properties": {
        "id": "fms-interface",
        "name": "FMS interface",
        "aka": [
          "FMS standard",
          "bus FMS"
        ],
        "section": "topic-pack",
        "definition": "The manufacturer-independent CAN data interface of trucks and buses, defined by the major European OEMs, that exposes vehicle data — including, for electric vehicles, battery state of charge, charging status and energy consumption — to fleet-management telematics.",
        "related": [
          "can-bus",
          "vdv-301",
          "fleet-telematics",
          "state-of-charge",
          "electric-bus",
          "j1939"
        ],
        "url": "https://lemonergy.com/learn/glossary/fms-interface/",
        "mentions": [
          "differential-electrochemical-mass-spectrometry"
        ]
      }
    },
    {
      "id": "term:inverter",
      "type": "Term",
      "label": "Inverter",
      "properties": {
        "id": "inverter",
        "name": "Inverter",
        "aka": [
          "power conversion system",
          "PCS"
        ],
        "section": "topic-pack",
        "definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.",
        "related": [
          "pre-charge",
          "dc-dc-converter",
          "stationary-storage",
          "energy-management-system",
          "direct-current",
          "iec-62477-1"
        ],
        "url": "https://lemonergy.com/learn/glossary/inverter/",
        "mentions": []
      }
    },
    {
      "id": "reference:cia-can",
      "type": "Reference",
      "label": "3rd generation of the CAN data link layer",
      "properties": {
        "title": "3rd generation of the CAN data link layer",
        "publisher": "CAN in Automation, CAN Newsletter",
        "url": "https://www.can-cia.org/public/fileadmin/cia/documents/publications/cnlm/december_2020/20-4_p4_third_generation_of_the_can_data_link_layer_protocol_yao_yao_cia.pdf",
        "type": "Technical article",
        "scope": "Classical CAN, CAN FD and CAN XL data-link concepts; publication describes the 2020 state.",
        "year": 2020,
        "accessed": "2026-10-27"
      }
    }
  ]
}