# Node information connected to your output

**URL:** <https://discourse.nodered.org/t/node-information-connected-to-your-output/79002>\
**Category:** General\
**Created:** [7 June 2023 02:24 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002 "2023-06-07T02:24:57Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![rlmariz](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@rlmariz](https://discourse.nodered.org/u/rlmariz)\
**Post date:** [7 June 2023 02:24 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/1 "2023-06-07T02:24:57Z")

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I'm in a project where the current node depends on information from the node connected to its output, what better way to do this?

Thanks

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [7 June 2023 06:44 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/2 "2023-06-07T06:44:27Z")

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Hi. Your question is super vague. Can you provide more detail?

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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:** [7 June 2023 07:52 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/3 "2023-06-07T07:52:10Z")

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Also explain what you need to do if the node is connected to multiple following nodes.

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**Author:** ![rlmariz](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@rlmariz](https://discourse.nodered.org/u/rlmariz)\
**Post date:** [7 June 2023 12:05 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/4 "2023-06-07T12:05:09Z")

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I want to simulate a mass-spring system.

spring\_1-\>mass\_1-\>spring\_2-\>mass\_2

In this system, to calculate mass 1, I need information about mass 2 that is in front of you.

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**Author:** ![rlmariz](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@rlmariz](https://discourse.nodered.org/u/rlmariz)\
**Post date:** [7 June 2023 12:07 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/5 "2023-06-07T12:07:13Z")

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In this case only one type of node will matter to me. It is necessary to go through all the nodes and get information of the specific type.

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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:** [7 June 2023 12:28 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/6 "2023-06-07T12:28:08Z")

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Are there nodes for each spring and each mass?

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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:** [7 June 2023 12:37 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/7 "2023-06-07T12:37:00Z")

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It sounds like flow context is ideal for this.

Instead of hard coding the masses in your simulation node[s] calculate based on the flow variables.

Set them in a change node:  
set flow.mass1 = 100  
set flow.mass2 = 50

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<div class="post-metadata">

**Author:** ![rlmariz](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@rlmariz](https://discourse.nodered.org/u/rlmariz)\
**Post date:** [7 June 2023 12:43 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/8 "2023-06-07T12:43:38Z")

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Yes, the spring connects the two masses.

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<div class="post-metadata">

**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:** [7 June 2023 13:02 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/9 "2023-06-07T13:02:21Z")

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In that case consider the inputs and outputs of each node type.

1. Each Spring has two inputs, the positions of each end. You can use two topic values to to identify them. It has one output, which is the current tension.

2. Each Mass has two inputs, the tension on each end, and one output, the position.

So the wiring will look like this, probably with change nodes to setup the topics as appropriate.

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/9/195606cd87201ab50b09780f868c9c4ed53f94c5.png)

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [6 August 2023 13:03 UTC](https://discourse.nodered.org/t/node-information-connected-to-your-output/79002/10 "2023-08-06T13:03:08Z")

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