# Modbus TCP tags null value

**URL:** <https://forum.inductiveautomation.com/t/modbus-tcp-tags-null-value/31931>\
**Category:** General Discussion\
**Created:** [February 4, 2020, 10:57pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-tags-null-value/31931 "2020-02-04T22:57:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![perryl](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/perryl/32/11266_2.png) [@perryl](https://forum.inductiveautomation.com/u/perryl)\
**Post date:** [February 4, 2020, 10:57pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-tags-null-value/31931/1 "2020-02-04T22:57:22Z")

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Hello Ignition users,

After adding a Modbus TCP Device to my OPC-UA server and adding the newly created tags in tag browser I am getting null values. Connection is indicating connected. I am using port 5106 and I have confirmed I can read those addresses on that IP address and port with a Modbus Master simulator. The device I am connecting to is an APC Smart-UPS 1500 with a network card (AP9630) and I am trying to retrieve its status. Below is the Addresses config:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/2X/4/4959ba29c5b8211183e940bf5979b84b8ec8cacf.png)

What am I doing wrong?

Thanks!

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<div class="post-metadata">

**Author:** ![perryl](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/perryl/32/11266_2.png) [@perryl](https://forum.inductiveautomation.com/u/perryl)\
**Post date:** [February 4, 2020, 11:16pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-tags-null-value/31931/2 "2020-02-04T23:16:04Z")

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OK, I figured out my error. I was using the entity number when all I needed was the base number:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/2X/a/a0db47d64384c9a38dc7cce2cf7c6c9553ec7e46.png)  
This worked.