# Modbus TCP device tags have "Bad" values

**URL:** <https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531>\
**Category:** Ignition\
**Created:** [August 29, 2023, 8:22pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531 "2023-08-29T20:22:49Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Emile\_Laplante](https://avatars.discourse-cdn.com/v4/letter/e/c57346/32.png) [@Emile\_Laplante](https://forum.inductiveautomation.com/u/Emile_Laplante)\
**Post date:** [August 29, 2023, 8:22pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531/1 "2023-08-29T20:22:49Z")

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Hi,

On a project, I read data from a modbus TCP device. Project was running great for a long time. But, now the values of the devices in ignition designer are all marked as "Bad":

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/7/57ace6e803fa5473ccce4c7fcef38e0a60e37825.png)

There is the status of the connection :

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/5/8/58882ff37908aa3b5252c7dd16d124d70f14d30d.png)

But on the gateway web page in OPC Quick Client, all the values are good :

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/1/f1220e89475e237d129a178499f06e69c9cebbab.png)

I tried create a new device, but I get the same error. What is the issue?

Thank you!

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**Author:** ![Patrick\_Chanthilack](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/patrick_chanthilack/32/42479_2.png) [@Patrick\_Chanthilack](https://forum.inductiveautomation.com/u/Patrick_Chanthilack)\
**Post date:** [September 5, 2023, 10:08pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531/2 "2023-09-05T22:08:24Z")

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Hey Emile\_Laplante,

Have you tried subscribing to the same tag SoC0 from Ignition's Quick Client? Any recent errors populated under the logs page regarding this Modbus device?

It seems like Ignition is able to see the tag value but values aren't populating in the tag browser. Can you also send a screenshot of the tag diagnostic by right clicking on the tag \> Edit \> Show Diagnostics near the right side of the tag name. This will give us a better indicator as to why we are getting Bad quality.

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**Author:** ![Emile\_Laplante](https://avatars.discourse-cdn.com/v4/letter/e/c57346/32.png) [@Emile\_Laplante](https://forum.inductiveautomation.com/u/Emile_Laplante)\
**Post date:** [September 15, 2023, 12:07pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531/3 "2023-09-15T12:07:21Z")

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There is a screenshot of the tag diagnostic :

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/2/0219a8c7ef7f24d9a3482ee21bcacda36f594ebd.png)

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<div class="post-metadata">

**Author:** ![Emile\_Laplante](https://avatars.discourse-cdn.com/v4/letter/e/c57346/32.png) [@Emile\_Laplante](https://forum.inductiveautomation.com/u/Emile_Laplante)\
**Post date:** [September 15, 2023, 1:31pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-device-tags-have-bad-values/78531/4 "2023-09-15T13:31:44Z")

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Found my problem, the modbus device is generated by a python script. Modbus registers were not the same.