# OPCUA ,MBTCP Driver 2 address subscribe quality "bad" at the same time

**URL:** <https://forum.inductiveautomation.com/t/opcua-mbtcp-driver-2-address-subscribe-quality-bad-at-the-same-time/64468>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [September 26, 2022, 9:51am UTC](https://forum.inductiveautomation.com/t/opcua-mbtcp-driver-2-address-subscribe-quality-bad-at-the-same-time/64468 "2022-09-26T09:51:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Pofer\_Wang](https://avatars.discourse-cdn.com/v4/letter/p/f4b2a3/32.png) [@Pofer\_Wang](https://forum.inductiveautomation.com/u/Pofer_Wang)\
**Post date:** [September 26, 2022, 9:51am UTC](https://forum.inductiveautomation.com/t/opcua-mbtcp-driver-2-address-subscribe-quality-bad-at-the-same-time/64468/1 "2022-09-26T09:51:27Z")

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Hello,everyone.  
I have a uncanny question.

I use ignition Modbus TCP driver, and address settin show below.

 ![2022-09-26 17_19_57-Window](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/f/afbe7e0c073eed3be0343590deb2e69087616f27.png)

I use OPC Quick Client subscribe the tag at the same time.  
It quality return “Bad”.

 ![error](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/6/b69f5e22f5acb02889cb6e05ad4e126d61551de9.png)

But if not at the same time.  
It quality return “Good”.

 ![KPI1 OK](https://us1.discourse-cdn.com/inductiveautomation/original/3X/8/0/80657b503c536c33764fba664e71d971b6e03610.png)  
 ![SYS1-2 OK](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/4/d4a1615a488b4100196768c0d8646394383ffb60.png)

So I create 2 Modbus TCP driver connection.  
But I think this not good way.

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [September 26, 2022, 12:28pm UTC](https://forum.inductiveautomation.com/t/opcua-mbtcp-driver-2-address-subscribe-quality-bad-at-the-same-time/64468/2 "2022-09-26T12:28:37Z")

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The Ignition driver will read consecutive addresses in a single function for efficiency by default, even though addresses in the middle aren’t needed. This is fine if the target device implements all addresses (typical of PLCs). But if an intermediate address doesn’t exist at all, this fails.

In the driver, you can turn off the “Span Gaps” setting to prevent this optimization.

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<div class="post-metadata">

**Author:** ![Pofer\_Wang](https://avatars.discourse-cdn.com/v4/letter/p/f4b2a3/32.png) [@Pofer\_Wang](https://forum.inductiveautomation.com/u/Pofer_Wang)\
**Post date:** [September 27, 2022, 1:04am UTC](https://forum.inductiveautomation.com/t/opcua-mbtcp-driver-2-address-subscribe-quality-bad-at-the-same-time/64468/3 "2022-09-27T01:04:00Z")

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thx…  
I do it.