# OPC UA vs Comm Protocols

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819>\
**Category:** Ignition\
**Tags:** ignition79\
**Created:** [April 24, 2018, 6:12pm UTC](https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819 "2018-04-24T18:12:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![GreggCava](https://avatars.discourse-cdn.com/v4/letter/g/65b543/32.png) [@GreggCava](https://forum.inductiveautomation.com/u/GreggCava)\
**Post date:** [April 24, 2018, 6:12pm UTC](https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819/1 "2018-04-24T18:12:37Z")

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We have an application where we need to pull data from remote devices, we are in the definition stage, since it will be a custom development in the device side, we can choose between using a device that supports a “mini” OPC-UA server form or a device that can talks an specific protocol.

From architecture and performance standpoint, what would it be better, using a device with embedded OPC-UA server capabilities or an specific protocol say “Modbus TCP”.

We are talking about 50-80 devices.

Thanks and Regards,

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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:** [April 24, 2018, 6:56pm UTC](https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819/2 "2018-04-24T18:56:00Z")

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OPC UA would be the best choice.

edit: MQTT might be a reasonable approach as well, if bandwidth is very tight, but then you need to introduce a broker and 3rd party modules…

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**Author:** ![GreggCava](https://avatars.discourse-cdn.com/v4/letter/g/65b543/32.png) [@GreggCava](https://forum.inductiveautomation.com/u/GreggCava)\
**Post date:** [April 24, 2018, 7:46pm UTC](https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819/3 "2018-04-24T19:46:22Z")

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Thanks for the quick response!

I believe there should be no limitation for the number of OPC Servers added to ignition, am I right?

As for MQTT, we were also considering it, but I am not sure we are ready for it.  
We are planing on test it and depending on results consider it for future applications.

Thank you

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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:** [April 24, 2018, 7:54pm UTC](https://forum.inductiveautomation.com/t/opc-ua-vs-comm-protocols/17819/4 "2018-04-24T19:54:56Z")

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> [@GreggCava](#):
>
> I believe there should be no limitation for the number of OPC Servers added to ignition, am I right?

No limit, and its implementation has evolved (and is evolving) towards a future where you could have hundreds or thousands of connections and it _shouldn't_ be an issue.