diff --git a/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs b/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
index 42e12d6..bdf3343 100644
--- a/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
+++ b/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
@@ -84,58 +84,57 @@ namespace YD_AllHeartRates.Api.Mqtt
                 return _queue.Writer.WriteAsync(msg, stoppingToken).AsTask();
             };
 
-            List<StudentDto> studentList;
-            List<S_Device> devices;
-
-            var studentListCacheKey = $"{AppSettings.StudentListCacheKey}_{AppSettings.SchoolCode}";
-            var deviceListCacheKey = $"{AppSettings.DeviceListCacheKey}_{AppSettings.SchoolCode}";
-
-            studentList = _caching.Get<List<StudentDto>>(studentListCacheKey);
-            devices = _caching.Get<List<S_Device>>(deviceListCacheKey);
-
-            if (studentList == null || devices == null)
-            {
-                studentList = (
-                   from s in _smartSportsContext.Student
-                   join c in _smartSportsContext.Class on s.ClassId equals c.Id
-                   join d in _smartSportsContext.Device on s.StudentNo equals d.StudentNo into sd
-                   from d in sd.DefaultIfEmpty()
-                   where s.SchoolCode == AppSettings.SchoolCode && s.StudentStatus == 1
-                   select new StudentDto
-                   {
-                       SchoolCode = s.SchoolCode,
-                       StudentNo = s.StudentNo,
-                       StudentName = s.StudentName,
-                       Sex = s.Sex,
-                       Age = s.Age,
-                       HeartRateId = d != null ? d.Code : "",
-                       JumpRopeId = d != null ? d.Code : "",
-                       ClassId = s.ClassId,
-                       ClassName = s.ClassName,
-                       GradeId = c.GradeId,
-                       GradeName = c.GradeName ?? "",
-                       DeviceType = d != null ? d.DeviceType : 0
-                   }
-               ).ToList();
-
-
-                devices = _smartSportsContext.Device.Where(x => x.SchoolCode == AppSettings.SchoolCode && !string.IsNullOrWhiteSpace(x.StudentNo)).ToList();
-
-                _caching.AddObject(studentListCacheKey, studentList, 600);
-                _caching.AddObject(deviceListCacheKey, devices, 600);
-            }
-
-            var heartRateEntities = new ConcurrentBag<HeartRateData>();
-            var jumpRopeEntities = new ConcurrentBag<JumpRopeData>();
-
-            var deviceHMap = devices.Where(x => x.DeviceType == 1).ToDictionary(x => x.Code, x => x.StudentNo);
-            var deviceJMap = devices.Where(x => x.DeviceType == 2).ToDictionary(x => x.Code, x => x.StudentNo);
-
-            var studentMap = studentList.GroupBy(x => x.StudentNo).ToDictionary(g => g.Key, g => g.First());
-
 
             await foreach (var batch in ReadBatchesAsync(stoppingToken))
             {
+                List<StudentDto> studentList;
+                List<S_Device> devices;
+
+                var studentListCacheKey = $"{AppSettings.StudentListCacheKey}_{AppSettings.SchoolCode}";
+                var deviceListCacheKey = $"{AppSettings.DeviceListCacheKey}_{AppSettings.SchoolCode}";
+
+                studentList = _caching.Get<List<StudentDto>>(studentListCacheKey);
+                devices = _caching.Get<List<S_Device>>(deviceListCacheKey);
+
+                if (studentList == null || devices == null)
+                {
+                    studentList = (
+                       from s in _smartSportsContext.Student
+                       join c in _smartSportsContext.Class on s.ClassId equals c.Id
+                       join d in _smartSportsContext.Device on s.StudentNo equals d.StudentNo into sd
+                       from d in sd.DefaultIfEmpty()
+                       where s.SchoolCode == AppSettings.SchoolCode && s.StudentStatus == 1
+                       select new StudentDto
+                       {
+                           SchoolCode = s.SchoolCode,
+                           StudentNo = s.StudentNo,
+                           StudentName = s.StudentName,
+                           Sex = s.Sex,
+                           Age = s.Age,
+                           HeartRateId = d != null ? d.Code : "",
+                           JumpRopeId = d != null ? d.Code : "",
+                           ClassId = s.ClassId,
+                           ClassName = s.ClassName,
+                           GradeId = c.GradeId,
+                           GradeName = c.GradeName ?? "",
+                           DeviceType = d != null ? d.DeviceType : 0
+                       }
+                   ).ToList();
+
+
+                    devices = _smartSportsContext.Device.Where(x => x.SchoolCode == AppSettings.SchoolCode && !string.IsNullOrWhiteSpace(x.StudentNo)).ToList();
+
+                    _caching.AddObject(studentListCacheKey, studentList, 600);
+                    _caching.AddObject(deviceListCacheKey, devices, 600);
+                }
+
+                var heartRateEntities = new ConcurrentBag<HeartRateData>();
+                var jumpRopeEntities = new ConcurrentBag<JumpRopeData>();
+
+                var deviceHMap = devices.Where(x => x.DeviceType == 1).ToDictionary(x => x.Code, x => x.StudentNo);
+                var deviceJMap = devices.Where(x => x.DeviceType == 2).ToDictionary(x => x.Code, x => x.StudentNo);
+
+                var studentMap = studentList.GroupBy(x => x.StudentNo).ToDictionary(g => g.Key, g => g.First());
 
                 Parallel.ForEach(batch, new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount }, msg =>
                 {