# OPC client read values only with default scan class

**URL:** <https://forum.inductiveautomation.com/t/opc-client-read-values-only-with-default-scan-class/9986>\
**Category:** Ignition\
**Created:** [May 6, 2015, 8:00am UTC](https://forum.inductiveautomation.com/t/opc-client-read-values-only-with-default-scan-class/9986 "2015-05-06T08:00:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Vita](https://avatars.discourse-cdn.com/v4/letter/v/51bf81/32.png) [@Vita](https://forum.inductiveautomation.com/u/Vita)\
**Post date:** [May 6, 2015, 8:00am UTC](https://forum.inductiveautomation.com/t/opc-client-read-values-only-with-default-scan-class/9986/1 "2015-05-06T08:00:42Z")

</div>

Hi,

I’am using Ignition 7.7.4 with Kepware OPC server 5.17.  
When I use a different class than the default, values are no longer read respectively the value is still 0. Writing value into OPC server is OK, but in Ignition remains 0. It happens in both OPC UA or DA connection.  
Ignition OPC server with non default scan class works without problems.

 ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/7/7e6fc351a5441d49742595550e4149a3f7f4207a.png)  

Picture show status of OPC class with test tags - [MaR\_UA] tags remain zero

---

<div class="post-metadata">

**Author:** ![Vita](https://avatars.discourse-cdn.com/v4/letter/v/51bf81/32.png) [@Vita](https://forum.inductiveautomation.com/u/Vita)\
**Post date:** [May 15, 2015, 8:52am UTC](https://forum.inductiveautomation.com/t/opc-client-read-values-only-with-default-scan-class/9986/2 "2015-05-15T08:52:10Z")

</div>

It seems like it is normal behavior of KEPserver in simulation mode.