133 lines
2.7 KiB
JSON
133 lines
2.7 KiB
JSON
{
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"title": "Vehicle CAN FD topology",
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"source": "IO_MODULES/CAN_PHYSICAL_LAYER.md: Topology, termination, and service access",
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"nodes": {
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"title": {
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"label": "Vehicle CAN FD \u00b7 continuous linear trunk",
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"bounds": [
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30,
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20,
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1100,
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45
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]
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},
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"subtitle": {
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"label": "500 kbit/s arbitration \u00b7 2 Mbit/s data phase \u00b7 approximately 2\u20132.5 m end-to-end",
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"bounds": [
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30,
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75,
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1100,
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40
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]
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},
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"rear": {
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"label": "Rear endpoint\n120 \u03a9 across CAN_H / CAN_L",
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"bounds": [
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30,
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170,
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290,
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105
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]
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},
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"ecu": {
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"label": "ECU \u00b7 local PCB junction\nMid-bus connection",
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"bounds": [
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440,
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170,
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280,
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105
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]
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},
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"front": {
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"label": "Front endpoint\n120 \u03a9 across CAN_H / CAN_L",
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"bounds": [
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840,
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170,
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290,
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105
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]
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},
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"distance1": {
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"label": "0.5\u20131 m",
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"bounds": [
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320,
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130,
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120,
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40
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]
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},
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"distance2": {
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"label": "1\u20131.5 m",
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"bounds": [
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720,
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130,
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120,
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40
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]
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},
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"ecu_note": {
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"label": "ECU transceiver joins locally on PCB.\nOptional ECU 120 \u03a9 termination: OPEN in V1;\nenable only if the ECU becomes an endpoint.",
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"bounds": [
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340,
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305,
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710,
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90
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]
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},
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"service": {
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"label": "Debug / service connector\nCAN_H \u00b7 CAN_L \u00b7 CAN_0V\nVery short PCB branch\nNo termination",
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"bounds": [
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440,
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480,
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350,
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110
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]
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},
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"busport": {
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"label": "Same local ECU bus",
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"bounds": [
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60,
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490,
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270,
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80
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]
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},
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"foot": {
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"label": "Lines above represent the CAN_H / CAN_L twisted pair, not individual conductors.\nAll nodes also share the defined CAN_0V reference. Avoid a long attached service cable.",
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"bounds": [
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30,
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625,
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1100,
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55
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]
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}
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},
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"connections": [
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{
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"from": "rear",
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"to": "ecu",
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"label": ""
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},
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{
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"from": "ecu",
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"to": "front",
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"label": ""
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},
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{
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"from": "busport",
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"to": "service",
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"label": ""
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}
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],
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"continuations": {
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"busport": "ecu"
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},
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"bus_model": "Each trunk line represents the differential CAN_H/CAN_L pair. CAN_0V is a separate shared reference.",
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"termination": {
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"rear": "120 ohm across CAN_H/CAN_L",
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"front": "120 ohm across CAN_H/CAN_L",
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"ecu": "120 ohm option, solder jumper normally open; endpoint use only",
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"service": "none"
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}
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}
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