appid:wx175455f13c7685f6
小程序名:海康守望
前置条件:1.已登记设备 2. 申请设备消息能力
订阅设备消息订阅requestSubscribeDeviceMessage一直提示
"errMsg": "requestSubscribeDeviceMessage:fail requestSubscribeDeviceMessage:fail check sn_ticket fail", "errCode": 19720726
问题点:sn是怎么获取的,是否需要在微信端预注册一下,还是怎么操作呢?

你好,请问是否有做设备接入,申请设备消息
https://developers.weixin.qq.com/miniprogram/dev/framework/device/device-access.html