goJt808 := service.New(
    service.WithHostPorts("0.0.0.0:808"),
    service.WithTerminalTimeout(30*time.Second, func(t service.TerminalTimeout) { /* 超时处理 */ }),
    service.WithCustomHandleFunc(func() map[consts.JT808CommandType]service.Handler {
        return map[consts.JT808CommandType]service.Handler{
            consts.T0200LocationReport: &myLocation{}, // 自定义经纬度处理
        }
    }),
)
go goJt808.Run()

type myLocation struct{ model.T0x0200 }

func (l *myLocation) OnReadExecutionEvent(msg *service.Message) {
    _ = l.Parse(msg.JTMessage)
    // l.Longitude, l.Latitude, l.Speed, l.AlarmSignDetails ...
    log.Printf("收到位置 key=%s", msg.Key)
}

func (l *myLocation) OnWriteExecutionEvent(_ service.Message) {}

msg := service.NewActiveMessage(phone, consts.P8201QueryLocation, nil, 3*time.Second)
reply := goJt808.SendActiveMessage(msg)
if reply.ExtensionFields.Err != nil { /* 超时或终端不在线 */ }