# Bind two opc tags togehter

**URL:** <https://forum.inductiveautomation.com/t/bind-two-opc-tags-togehter/22924>\
**Category:** Ignition\
**Tags:** scripting\
**Created:** [February 27, 2019, 2:18pm UTC](https://forum.inductiveautomation.com/t/bind-two-opc-tags-togehter/22924 "2019-02-27T14:18:01Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![florent.gelas](https://avatars.discourse-cdn.com/v4/letter/f/4da419/32.png) [@florent.gelas](https://forum.inductiveautomation.com/u/florent.gelas)\
**Post date:** [February 27, 2019, 2:18pm UTC](https://forum.inductiveautomation.com/t/bind-two-opc-tags-togehter/22924/1 "2019-02-27T14:18:01Z")

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Hello,

I would like to do read an OPC tag “tag\_1” from a device “device1” and bind it to an other OPC tag “tag2” from a device “device2” using ModBus TCP protocol.  
The objectif is to collect informations from different devices and write it to a single.

For the moment i’m using a script like this :

```
values = system.tag.readAll(readTag)
listValues = []
for val in values:
    listValues .append(val.getValue())

values2 = system.tag.writeAll(writeTag,listValues) 

```

The problem with this solution is that i have many tags to read/write.  
I would like to know if there is an other way to do this.

Thanks,  
Florent

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<div class="post-metadata">

**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\
**Post date:** [February 27, 2019, 2:42pm UTC](https://forum.inductiveautomation.com/t/bind-two-opc-tags-togehter/22924/2 "2019-02-27T14:42:34Z")

</div>

What about [Derived tags](https://docs.inductiveautomation.com/display/DOC79/Types+of+Tags#TypesofTags-DerivedTags)?

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<div class="post-metadata">

**Author:** ![florent.gelas](https://avatars.discourse-cdn.com/v4/letter/f/4da419/32.png) [@florent.gelas](https://forum.inductiveautomation.com/u/florent.gelas)\
**Post date:** [February 27, 2019, 4:30pm UTC](https://forum.inductiveautomation.com/t/bind-two-opc-tags-togehter/22924/3 "2019-02-27T16:30:40Z")

</div>

I did not manage to write a derivative tag from an opc tag to on an other opc tag