{
  "url": "https://openlegislation.uk/eu-regulation-1985-3821/annex-2/appendix-6",
  "json_url": "https://openlegislation.uk/eu-regulation-1985-3821/annex-2/appendix-6.json",
  "legislation": "eur/1985/3821",
  "legislation_title": "Council Regulation (EEC) No 3821/85 of 20 December 1985 on recording equipment in road transport",
  "legislation_url": "https://openlegislation.uk/eu-regulation-1985-3821",
  "path": "annex/2/appendix/6",
  "kind": "appendix",
  "number": "6",
  "heading": "EXTERNAL INTERFACES",
  "text": "1.\nHARDWARE\n1.1.\nConnector\nINT_001 The downloading/calibration connector shall be a six pin connector, accessible on the front panel without the need to disconnect any part of the recording equipment, and shall comply with the following drawing (all dimensions in millimetres):\nThe following diagram shows a typical six pin mating plug:\n1.2.\nContact allocation\nINT_002 Contacts shall be allocated in accordance with the following table:\nPin\nDescription\nRemark\n1\nBattery minus\nConnected to the battery minus of the vehicle\n2\nData communication\nK-line (ISO 14 230-1)\n3\nRxD — Downloading\nData input to recording equipment\n4\nInput/output signal\nCalibration\n5\nPermanent power output\nThe voltage range is specified to be that of the vehicle power minus 3V to allow for the voltage drop across the protective circuitry\nOutput 40 mA\n6\nTxD — Downloading\nData output from recording equipment\n1.3.\nBlock diagram\nINT_003 The block diagram shall comply with the following:\n2.\nDOWNLOADING INTERFACE\nINT_004 The downloading interface shall comply to RS232 specifications.\nINT_005 The downloading interface shall use one start bit, 8 data bits LSB first, one even parity bit and 1 stop bit.\nStart bit one bit with logic level 0\nData bits transmitted with LSB first\nParity bit even parity\nStop bit one bit with logic level 1\nWhen numerical data composed by more than one byte are transmitted, the most significant byte is transmitted first and the least significant byte last.\nINT_006 Transmission baud rates shall be adjustable from 9 600 bps to 115 200 bps. Transmission shall be achieved at the highest possible transmission speed, the initial baud rate after a start of communication being set at 9 600 bps.\n3.\nCALIBRATION INTERFACE\nINT_007 The data communication shall comply to ISO 14 230-1 Road vehicles — Diagnostic systems — Keyword protocol 2000 — Part 1: Physical layer, First edition: 1999.\nINT_008 The input/output signal shall comply with the following electrical specification:\nParameter\nMinimum\nTypical\nMaximum\nRemark\nU low (in)\n1,0 V\nI = 750 μA\nU high (in)\n4 V\nI = 200 μA\nFrequency\n4 kHz\nU low (in)\n1,0 V\nI = 1 mA\nU high (out)\n4 V\nI = 1 mA\nINT_009 The input/output signal shall comply with the following timing diagrams:\nSensor signal (out)\nTest signal (in)\nUTC clock signal (out)",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Inserted by Council Regulation (EC) No 2135/98 of 24 September 1998 amending Regulation (EEC) No 3821/85 on recording equipment in road transport and Directive 88/599/EEC concerning the application of Regulations (EEC) No 3820/85 and (EEC) No 3821/85."
    },
    {
      "type": "F",
      "label": "F2",
      "text": "Substituted by Commission Regulation (EC) No 1360/2002 of 13 June 2002 adapting for the seventh time to technical progress Council Regulation (EEC) No 3821/85 on recording equipment in road transport (Text with EEA relevance)."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/1985/3821/annex/2/appendix/6",
    "retrieved_at": "2026-11-01T15:05:16.849228+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}