# Publish Values via Modbus

**URL:** <https://forum.inductiveautomation.com/t/publish-values-via-modbus/3961>\
**Category:** General Discussion\
**Created:** [February 7, 2012, 9:50am UTC](https://forum.inductiveautomation.com/t/publish-values-via-modbus/3961 "2012-02-07T09:50:38Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![inthebox](https://avatars.discourse-cdn.com/v4/letter/i/5e9695/32.png) [@inthebox](https://forum.inductiveautomation.com/u/inthebox)\
**Post date:** [February 7, 2012, 9:50am UTC](https://forum.inductiveautomation.com/t/publish-values-via-modbus/3961/1 "2012-02-07T09:50:38Z")

</div>

Hi, I need to configure the Modbus Server in order to publish tags and make them readable by an external Modbus client.  
How can I do?  
Where can I set the Modbus registers on which a tag is published?

Thank you.

---

<div class="post-metadata">

**Author:** ![marioquark](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@marioquark](https://forum.inductiveautomation.com/u/marioquark)\
**Post date:** [February 7, 2012, 10:42am UTC](https://forum.inductiveautomation.com/t/publish-values-via-modbus/3961/2 "2012-02-07T10:42:14Z")

</div>

hi,  
i have the same need: i read data from an opc module and i want to republish them via modbus (ignition as modbus client). is it possible?  
thanx

---

<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:** [February 7, 2012, 3:09pm UTC](https://forum.inductiveautomation.com/t/publish-values-via-modbus/3961/3 "2012-02-07T15:09:55Z")

</div>

It’s not possible to publish values via Modbus. The only mechanisms to expose values to external systems is via OPC-UA or SQLTags/Database.

Ignition’s Modbus module is currently a “client” (in Modbus terminology, “master”) only.