diff --git a/AsbCloudInfrastructure/Repository/WitsRecordRepository.cs b/AsbCloudInfrastructure/Repository/WitsRecordRepository.cs
index 1be9a7de..0c750c6b 100644
--- a/AsbCloudInfrastructure/Repository/WitsRecordRepository.cs
+++ b/AsbCloudInfrastructure/Repository/WitsRecordRepository.cs
@@ -66,17 +66,33 @@ namespace AsbCloudInfrastructure.Repository
             return new TDto[] { Convert(data, timezoneHours) };
         }
 
-        public Task SaveDataAsync(int idTelemetry, IEnumerable<TDto> dtos, CancellationToken token)
+        public async Task SaveDataAsync(int idTelemetry, IEnumerable<TDto> dtos, CancellationToken token)
         {
             if (dtos?.Any() != true)
-                return Task.CompletedTask;
+                return;
 
             var timezoneHours = telemetryService.GetTimezone(idTelemetry).Hours;
             var entities = dtos
                 .DistinctBy(d => d.DateTime)
                 .Select(dto => Convert(dto, idTelemetry, timezoneHours));
-            dbset.AddRange(entities);
-            return db.SaveChangesAsync(token);
+
+            var dateMin = entities.Min(e => e.DateTime);
+            var dateMax = entities.Max(e => e.DateTime);
+            var existingEntities = await dbset
+                .Where(e => e.IdTelemetry == idTelemetry)
+                .Where(e => e.DateTime >= dateMin && e.DateTime <= dateMax)
+                .Select(e => new { e.DateTime, e.IdTelemetry})
+                .ToArrayAsync(token);
+
+            foreach (var entity in entities)
+            {
+                if (existingEntities.Any(e=>e.IdTelemetry == entity.IdTelemetry && e.DateTime == entity.DateTime))                
+                    dbset.Update(entity);                
+                else
+                    dbset.Add(entity);
+            }
+            
+            await db.SaveChangesAsync(token);
         }
 
         private static TEntity Convert(TDto dto, int idTelemetry, double timezoneHours)