# Retrieving a single Bacnet "Present Value" only

**URL:** <https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045>\
**Category:** General\
**Created:** [30 January 2024 13:30 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045 "2024-01-30T13:30:34Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Berx](https://avatars.discourse-cdn.com/v4/letter/b/5daacb/32.png) [@Berx](https://discourse.nodered.org/u/Berx)\
**Post date:** [30 January 2024 13:30 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/1 "2024-01-30T13:30:34Z")

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Hi,

I have a connection to a BACnet device and by using a BACnet Read-Node, I get a very lengthy reply.

 ![flow_read room Temp](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/2/2/226cc6afe055ff3b19597cef1749e49e634d7da3.png)  
 ![debug_room_temp](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/8/a85acf7c73a2976b54ac975cfcd44877dfabbc2e.png)

However, I only need the value (in my case a room temperature).  
How do I extract only the required value form the payload with all these arrays?

Your help is much appreciated, thanks.  
Best regards,  
Berx

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [30 January 2024 13:42 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/2 "2024-01-30T13:42:51Z")

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There’s a great page in the docs ([Working with messages : Node-RED](https://nodered.org/docs/user-guide/messages)) that will explain how to use the debug panel to find the right path to any data item.

Pay particular attention to the part about the buttons that appear under your mouse pointer when you over hover a debug message property in the sidebar.

![BX00Cy7yHi](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/b/d/bd1f333a9e043b061b39917c328b0094d3e52d30.gif)

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**Author:** ![Berx](https://avatars.discourse-cdn.com/v4/letter/b/5daacb/32.png) [@Berx](https://discourse.nodered.org/u/Berx)\
**Post date:** [30 January 2024 21:27 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/3 "2024-01-30T21:27:37Z")

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Thanks, I was hopinh that there would be a special BACnet node available to enable me to quickly select the present value, but I'll take a deeper dice into the structures, thanks again.

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**Author:** ![jbudd](https://avatars.discourse-cdn.com/v4/letter/j/5f8ce5/32.png) [@jbudd](https://discourse.nodered.org/u/jbudd)\
**Post date:** [30 January 2024 22:27 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/4 "2024-01-30T22:27:42Z")

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> [@Berx](#):
>
> I'll take a deeper dive into the structures

It's hardly complicated, the data you want is at msg.payload.values[0].value.  
@Colin has shown you how to confirm that.

Use a change node to set msg.payload.

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/d/c/dc1fd47750664bfc8f2da5f9c110c6fc39ff5523.png)

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**Author:** ![Berx](https://avatars.discourse-cdn.com/v4/letter/b/5daacb/32.png) [@Berx](https://discourse.nodered.org/u/Berx)\
**Post date:** [31 January 2024 18:15 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/5 "2024-01-31T18:15:56Z")

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Thanks, that seems very simple to me and whatever does the job is just perfect - thanks again, it helps me a lot.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [30 April 2024 18:15 UTC](https://discourse.nodered.org/t/retrieving-a-single-bacnet-present-value-only/85045/6 "2024-04-30T18:15:58Z")

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