# Impossible to read Modicon bit after update to 7.3.1?

**URL:** <https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595>\
**Category:** Ignition\
**Created:** [November 13, 2011, 5:53pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595 "2011-11-13T17:53:50Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Tjoeben](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tjoeben](https://forum.inductiveautomation.com/u/Tjoeben)\
**Post date:** [November 13, 2011, 5:53pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/1 "2011-11-13T17:53:50Z")

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I had created several bit reads and that works fine until the update to version 7.3.1

Before the update the “OPC item path” looks like this: [PLC22]L401203.6, after the update the “OPC item path” must be now like this : [PLC22]22.L401203.6 So I fix several tags so that it will work for the new version.  
The value of a normal (not bitwise) holding register will be read perfect in the new version.  
But reading a bit will not work. When I check the Tag Diagnostics I get the message “Unknown”.  
After a few days when I check again with tag Diagnostics then is the message; “Stale”.

I use Modbus Driver v2 2.3.1 (b159)

Is there is something changed with the bit reading in this new version ?

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 13, 2011, 6:04pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/2 "2011-11-13T18:04:05Z")

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Nothing should have changed…

What version did you upgrade from? 7.3.0 or something from the 7.2.x line?

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 13, 2011, 6:12pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/3 "2011-11-13T18:12:19Z")

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You might also go to the Levels tab, search for a logger named “XOPCAddressSpace”, and turn the level to DEBUG.

Then if you could post your log.bin.gz file here I could take a look.

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 13, 2011, 6:53pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/4 "2011-11-13T18:53:20Z")

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Ok, don’t worry about any of what I previously said. I was able to reproduce this.

…and fix it. It will be available Monday with the rest of the next 7.3.2 beta.

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<div class="post-metadata">

**Author:** ![Tjoeben](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tjoeben](https://forum.inductiveautomation.com/u/Tjoeben)\
**Post date:** [November 13, 2011, 8:00pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/5 "2011-11-13T20:00:35Z")

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I make an update from version 7.2.7

In the log file you can see that I have not yet update all the tags to the new form [PLC22]22.V…

I have do fix several tags, but a moment I notice that bits would n 't be read , so I stop the fixing temporarily.

Thanks Kevin.  
[logs.bin.gz](https://us1.discourse-cdn.com/inductiveautomation/original/1X/4f2c9e3c34e46a1ebfd56e2068d851e6404dd4c1.gz) (339 KB)

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<div class="post-metadata">

**Author:** ![Tjoeben](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tjoeben](https://forum.inductiveautomation.com/u/Tjoeben)\
**Post date:** [November 13, 2011, 8:15pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/6 "2011-11-13T20:15:18Z")

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Hello Kevin,

I see you have already fix the problem.  
I have aborted the upload from the log-file.

Tomorrow I try the new version.

Thanks a lot.

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 14, 2011, 6:59pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/7 "2011-11-14T18:59:18Z")

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The beta build including the fixed Modbus-v2 module is available [here](http://inductiveautomation.com/downloads/ignition/development).

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<div class="post-metadata">

**Author:** ![Tjoeben](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tjoeben](https://forum.inductiveautomation.com/u/Tjoeben)\
**Post date:** [November 14, 2011, 11:28pm UTC](https://forum.inductiveautomation.com/t/impossible-to-read-modicon-bit-after-update-to-7-3-1/3595/8 "2011-11-14T23:28:07Z")

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Thank you very much Kevin,  
reading the bits works now again fine.

Super. ![:thumb_right:](https://us1.discourse-cdn.com/inductiveautomation/original/1X/2026e28c0c425034352c1b75807edf956adc75f4.gif ":thumb\_right:")