{
  "self": "urn:mrn:signalk:uuid:c0d79334-4e25-4245-8892-54e8ccc8021d",
  "vessels": {
    "urn:mrn:signalk:uuid:c0d79334-4e25-4245-8892-54e8ccc8021d": {
      "uuid": "urn:mrn:signalk:uuid:c0d79334-4e25-4245-8892-54e8ccc8021d",
      "propulsion": {
        "instance0": {
          "label": "Port Engine",
          "revolutions": {
            "value": 1280,
            "timestamp": "2014-08-15T19:00:15.402Z",
            "$source": "foo.bar",
            "meta": {
              "displayName": "Port Tachometer",
              "longName": "Engine 2 Tachometer",
              "shortName": "Tacho",
              "description": "Engine revolutions (x60 for RPM)",
              "units": "Hz",
              "timeout": 1,
              "displayScale": {
                "lower": 0,
                "upper": 75,
                "type": "linear"
              },
              "alertMethod": [
                "visual"
              ],
              "warnMethod": [
                "visual"
              ],
              "alarmMethod": [
                "sound",
                "visual"
              ],
              "emergencyMethod": [
                "sound",
                "visual"
              ],
              "zones": [
                {
                  "upper": 4,
                  "state": "alarm",
                  "message": "Stopped or very slow"
                },
                {
                  "lower": 4,
                  "upper": 60,
                  "state": "normal"
                },
                {
                  "lower": 60,
                  "upper": 65,
                  "state": "warn",
                  "message": "Approaching maximum"
                },
                {
                  "lower": 65,
                  "state": "alarm",
                  "message": "Exceeding maximum"
                }
              ]
            }
          }
        }
      }
    }
  },
  "version": "1.0.0"
}