# Scan Class and OPC Data Mode - Read

**URL:** <https://forum.inductiveautomation.com/t/scan-class-and-opc-data-mode-read/10118>\
**Category:** Ignition\
**Created:** [June 11, 2015, 1:58pm UTC](https://forum.inductiveautomation.com/t/scan-class-and-opc-data-mode-read/10118 "2015-06-11T13:58:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jdelgado](https://avatars.discourse-cdn.com/v4/letter/j/85f322/32.png) [@jdelgado](https://forum.inductiveautomation.com/u/jdelgado)\
**Post date:** [June 11, 2015, 1:58pm UTC](https://forum.inductiveautomation.com/t/scan-class-and-opc-data-mode-read/10118/1 "2015-06-11T13:58:30Z")

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Hi,

I have question about how Scan Class and OPC Data Mode set as read in the transactions groups. If I have tags setup in the default scan class of 1 secs but I set my Transactions to OPC Data Mode Read does it overrides the scan class.

I assume the transaction trigger will be updated based on the scan class but when the condition is true SQL Bridge will force a tag read since I have OPC Data Mode set to read.

Thanks