机场2上云问题

{
  "method": "airport_organization_bind",
  "bid": "b7123c33-53ae-4eee-9756-60123152109d",
  "tid": "2706b9ad-36c6-46b3-825f-96f1df756bac",
  "timestamp": 1733207938403,
  "data": {
    "bind_devices": [
      {
        "device_binding_code": "qwe",
        "organization_id": "W",
        "device_callsign": "",
        "sn": "7CTDM7900B76T6",
        "device_secret": "4a9cf9bcb9c99b8101e0fafe591afdc0",
        "device_nonce": "04f517fbb67aad224d4d284cb76cc883",
        "device_model_key": "3-2-0"
      },
      {
        "device_binding_code": "qwe",
        "organization_id": "W",
        "device_callsign": "",
        "sn": "1581F6Q8D23CM00A451T",
        "device_secret": "ca71499e78e746d31c4d532336816441",
        "device_nonce": "f64d66417260c66edcc6dbbbbd417a0e",
        "device_model_key": ""
      }
    ]
  },
  "gateway": "7CTDM7900B76T6"
}

无人机的 "device_model_key": ""为空是什么原因，是否是正常的，无人机开机的并且也对过频