# Ignition Modbus Slave functionality - Automation professionals

**URL:** <https://forum.inductiveautomation.com/t/ignition-modbus-slave-functionality-automation-professionals/92132>\
**Category:** Ignition\
**Created:** [June 20, 2024, 12:19am UTC](https://forum.inductiveautomation.com/t/ignition-modbus-slave-functionality-automation-professionals/92132 "2024-06-20T00:19:50Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**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:** [June 20, 2024, 1:29am UTC](https://forum.inductiveautomation.com/t/ignition-modbus-slave-functionality-automation-professionals/92132/2 "2024-06-20T01:29:17Z")

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> [@denny\_jimenez](#):
>
> How can I affect the value of this tag (OPCSlaveTag1), for example with that of another OPC TAG (OPCClientTag2) that I read as Ignition Client?

I recommend the technique I describe here:

> [@Modbus Slave/Server to Generate Read Only Tags](https://forum.inductiveautomation.com/t/modbus-slave-server-to-generate-read-only-tags/87583/21):
>
> I've create a generic "Modbus Publish" script that eliminates the need for a second set of tags. I've publicly posted it here: [https://www.automation-pros.com/ignition/modbusPublish.py](https://www.automation-pros.com/ignition/modbusPublish.py) It requires the "Queue Utility" script posted here: [https://www.automation-pros.com/ignition/queueUtil.py](https://www.automation-pros.com/ignition/queueUtil.py) and described over here: Both scripts rely on my Integration Toolkit's globalVarMap() script function, but you can rework that (not quite 1:1) to use system.util.getGlobals() if you must. (Not recomme…

> [@denny\_jimenez](#):
>
> how to buy the driver.

You found my website, which has this page:

[https://www.automation-pros.com/modulesales.html](https://www.automation-pros.com/modulesales.html)

From where you can find all current downloads, and my sales policy/procedures document:

[https://www.automation-pros.com/Module%20Sales-2023-04-07.pdf](https://www.automation-pros.com/Module%20Sales-2023-04-07.pdf)

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