# Modbus with OpenPLC

**URL:** https://discourse.nodered.org/t/modbus-with-openplc/6536
**Category:** General
**Created:** [8 January 2019 05:10 UTC](https://discourse.nodered.org/t/modbus-with-openplc/6536 "2019-01-08T05:10:36Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![noobPLC](https://avatars.discourse-cdn.com/v4/letter/n/b5e925/32.png) [@noobPLC](https://discourse.nodered.org/u/noobPLC)
#### Post date: [8 January 2019 05:10 UTC](https://discourse.nodered.org/t/modbus-with-openplc/6536/1 "2019-01-08T05:10:36Z")

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I want to write a value 1 to a openPLC ( with IP 10.10.10.83 ) using modbus write node.  
what values should I put in Unit-Id , Address , Add new Modbus client. As shown in the screenshot.

Thanks for the help in advance.

With warm regards.

 ![Screenshot%20from%202019-01-08%2000-06-08](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/e/ef3eb86d4cc8f8e34305c01ad7761ddcaddccf78.png)

 ![Screenshot%20from%202019-01-08%2000-09-36](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/8/8fb5176e4dce8526e80da8e7cd0c1553b963936b.png)

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### Author: ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)
#### Post date: [8 January 2019 07:07 UTC](https://discourse.nodered.org/t/modbus-with-openplc/6536/2 "2019-01-08T07:07:37Z")

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At least some of the answers are in the info panel on the right hand side…

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<div class="post-metadata">

### Author: ![noobPLC](https://avatars.discourse-cdn.com/v4/letter/n/b5e925/32.png) [@noobPLC](https://discourse.nodered.org/u/noobPLC)
#### Post date: [8 January 2019 07:10 UTC](https://discourse.nodered.org/t/modbus-with-openplc/6536/3 "2019-01-08T07:10:44Z")

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I have filled the following values from info i got from panel on right hand side.

![Screenshot%20from%202019-01-08%2002-09-14](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/e/eb588013f8bd2bfc5a4d3706358f7843793d1731.png)

![Screenshot%20from%202019-01-08%2002-09-23](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/f/f382276455280fe0c9b778c9f6bba163c4000a88.png)

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### Author: ![noobPLC](https://avatars.discourse-cdn.com/v4/letter/n/b5e925/32.png) [@noobPLC](https://discourse.nodered.org/u/noobPLC)
#### Post date: [8 January 2019 10:41 UTC](https://discourse.nodered.org/t/modbus-with-openplc/6536/4 "2019-01-08T10:41:39Z")

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I was able to configure the modbus write node and connect to the openPLC instance running on my localhost ( IP: 127.0.0.1 and OS: linux ) successfully. however when I run the openPLC instance on Raspberry PI i am not able to connect my modbus write node. any suggestions ?  
Both RPI and system where my node-red is running is pingable.