# Siemens S7-300 The combination data is not synchronized **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [February 21, 2023, 4:54am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096 "2023-02-21T04:54:35Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![770043297](https://avatars.discourse-cdn.com/v4/letter/7/b9bd4f/32.png) [@770043297](https://forum.inductiveautomation.com/u/770043297)\ **Post date:** [February 21, 2023, 4:54am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/1 "2023-02-21T04:54:35Z")
There are two OPC tags WasteCount，WasteCode When WasteCount + 1 is used, the Transaction Group is used to record data The rate is 300 ```auto ID WasteCount WasteCode t_stamp 1 1 1001 ``` But you lose a fraction of your data a day 5%, Other software has been used to record using the same PLC connection without loss How should I diagnose the cause of the loss😩 ---
**Author:** ![770043297](https://avatars.discourse-cdn.com/v4/letter/7/b9bd4f/32.png) [@770043297](https://forum.inductiveautomation.com/u/770043297)\ **Post date:** [February 21, 2023, 7:35am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/2 "2023-02-21T07:35:06Z")
😭 ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [February 21, 2023, 12:18pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/3 "2023-02-21T12:18:46Z")
Do you mean 300ms? That is quite fast if there is anything else being monitored there. Consider using OPC items instead of Ignition tags, and setting the transaction group to OPC "Read" mode instead of "Subscribed". ---
**Author:** ![770043297](https://avatars.discourse-cdn.com/v4/letter/7/b9bd4f/32.png) [@770043297](https://forum.inductiveautomation.com/u/770043297)\ **Post date:** [February 22, 2023, 3:52am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/4 "2023-02-22T03:52:52Z")
![Fixloss](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/0/d0f27572db4868cca3c65d4fed09c1a40d57b255.png) Am I configuring this correctly? I agree with you. I want him to succeed 🤗 ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [February 22, 2023, 12:20pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/5 "2023-02-22T12:20:27Z")
Those are tag references. You need OPC items. ---
**Author:** ![770043297](https://avatars.discourse-cdn.com/v4/letter/7/b9bd4f/32.png) [@770043297](https://forum.inductiveautomation.com/u/770043297)\ **Post date:** [March 28, 2023, 3:19am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/6 "2023-03-28T03:19:38Z")
I've been running this configuration for a while, but I still find some data missing. It's a little bit better than before. This is my configuration, I am not sure if the OPC items you said were created like this 😶‍🌫️ ![FixWaste](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/3/93ae0f4d5e958d2aab4bae58f0229b6e55b9d4d5.png) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [March 28, 2023, 12:04pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-the-combination-data-is-not-synchronized/70096/7 "2023-03-28T12:04:22Z")
Are you sure that the PLC is setting the Code **before** the Count? (The trigger must be the last thing changed in the PLC.)