com.mbta.ctd.subwayside.train-heartbeat

Train heartbeat received from the OL/RL wayside servers.

Heartbeats are sent approximately every 15 seconds, with a delay of approximately 10-15 seconds.

{
  "specversion": "1.0",
  "type": "com.mbta.ctd.subwayside.train-heartbeat",
  "id": "200081266220230427135628421",
  "source": "hsctdprd.mbta.com/subwayside-12345",
  "time": "2023-05-22T13:32:45Z",
  "partitionkey": "O2000812662",
  "data": {
    "receivedDt": "2023-04-27T13:56:28.420999Z",
    "createdDt": "2023-05-22T13:32:45Z",
    "transmissionDt": "2023-05-22T13:33:00Z",
    "flags": {
      "transmissionDtValid": true,
      "shopMode": false,
      "timeSyncGps": true,
      "speedValid": true,
      "gpsValid": true,
      "operationDataValid": true,
      "critical": true
    },
    "commId": 51462,
    "commCarNumber": "1445",
    "activeCarNumber": "1445",
    "primaryCarNumber": "1445",
    "sourceCarNumber": "1445",
    "leadCarNumber": "1445",
    "operationLine": "Orange",
    "trainDirection": "LEFT",
    "numberOfCars": 6,
    "leaderMcuCarNumber": "1445",
    "masterMcuCarNumbers": [
      "1234",
      "2345"
    ],
    "cars": [
      {
        "carNumber": "1445",
        "type": "CAB",
        "flags": {
          "dead": false,
          "critical": true,
          "master": true,
          "faultLog": false,
          "mileageValid": true,
          "maintenancePasswordVersionValid": true,
          "cellularUp": false,
          "wifiUp": [
            false,
            false
          ]
        },
        "maintenancePasswordVersion": "00.00",
        "mileageMi": 78920.9846,
        "systems": {
          "gcu1": {
            "online": false
          },
          "gcu2": {
            "online": false
          },
          "api": {
            "online": false
          },
          "atpN": {
            "online": false
          },
          "atpR": {
            "online": false
          },
          "nvr": {
            "online": false
          },
          "vms": {
            "online": false
          },
          "mcu": {
            "online": false
          },
          "dcuA1": {
            "online": false
          },
          "dcuA2": {
            "online": false
          },
          "dcuB1": {
            "online": false
          },
          "dcuB2": {
            "online": false
          },
          "dcuC1": {
            "online": false
          },
          "dcuC2": {
            "online": false
          },
          "dcuD1": {
            "online": false
          },
          "dcuD2": {
            "online": false
          },
          "dcuE1": {
            "online": false
          },
          "dcuE2": {
            "online": false
          },
          "dcuF1": {
            "online": false
          },
          "dcuF2": {
            "online": false
          },
          "dcuG1": {
            "online": false
          },
          "dcuG2": {
            "online": false
          },
          "dcuH1": {
            "online": false
          },
          "dcuH2": {
            "online": false
          },
          "ers": {
            "online": false
          },
          "mbcu1": {
            "valid": true,
            "online": false,
            "faultSeverity": 0,
            "fault": false
          },
          "mbcu2": {
            "online": false
          },
          "hvac1": {
            "online": false
          },
          "hvac2": {
            "online": false
          },
          "pcu1": {
            "online": false
          },
          "pcu2": {
            "online": false
          },
          "lvps": {
            "online": false
          },
          "gwuc": {
            "online": false
          }
        },
        "faultSeverity": null,
        "airSpringPressure": [
          564,
          564
        ],
        "loadWeightLb": [
          79280,
          79280
        ],
        "gwucWanState": "INITIALIZING",
        "wifiState": [
          "CONNECTING",
          "DISABLED"
        ]
      }
    ],
    "speedMph": 5,
    "latitude": 42.437278,
    "longitude": -71.07084,
    "destinationStation": null,
    "currentStation": {
      "id": 376,
      "name": "Malden Center"
    },
    "nextStation": null,
    "runningDistanceMi": 11.147,
    "routeCode": "1002"
  }
}

Loading com.mbta.ctd.subwayside.train-heartbeat...

Crowding

For calculating crowding, the important fields are:

• /data/leadCarNumber: the lead car has the operator (one additional person)
• /data/cars[*]/type: CAB or NON_CAB (non-cab cars have a higher capacity)
• /data/cars[*]/loadWeightLb[*]: weights from the two MBCU sensors. it's possible for one or both of them to be 0.