# Same Serial Port Connected in Two Flow files Not working

**URL:** <https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274>\
**Category:** General\
**Created:** [17 June 2021 05:01 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274 "2021-06-17T05:01:34Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![avinash-choudhary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/avinash-choudhary/32/42659_2.png) [@avinash-choudhary](https://discourse.nodered.org/u/avinash-choudhary)\
**Post date:** [17 June 2021 05:01 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/1 "2021-06-17T05:01:35Z")

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Hi Team

I am trying to add COM2 in two flow files Flow1 and Flow2. The data is displayed in both flows initially . But when we disable and enable Flow1 then the Flow2 serial port is not displaying the data though it displays connected .

FLOW1

 ![Screenshot 2021-06-17 at 11.21.48 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/e/f/ef2ec5a2becd20e33208843648c7a80e6f7bc2d3.png)

FLOW2

 ![Screenshot 2021-06-17 at 11.21.52 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/3/739fad492dda55926025c893d08134cd51a4b56f.png)

Initial Debug Message  
 ![Screenshot 2021-06-17 at 11.21.58 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/f/a/fa26bb56cd1955edf7a859a34777eec8ad255d80.png)

Disable and enable FLOW2 from postman

 ![Screenshot 2021-06-17 at 11.25.22 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/9/e/9e6edfec8565c0f167e2828016f3451305263b37.jpeg)  
 ![Screenshot 2021-06-17 at 11.25.03 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/e/7/e7b80a9f641020fdbd26a054024567a9a39e48f7.jpeg)

Debug Message after disable and enable

 ![Screenshot 2021-06-17 at 11.25.38 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/9/f/9fd7eadb72228265508acfbce302182abdbd7af7.png)

As u noticed the Flow1 Data is not displaying in the Debug Window though both flows are connected

@dceejay  
@Colin

Thanks,  
Avinash

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<div class="post-metadata">

**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [17 June 2021 06:54 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/2 "2021-06-17T06:54:17Z")

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You can't open the same come port twice.  
The easiest and only way is to split the output of one port node.

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**Author:** ![avinash-choudhary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/avinash-choudhary/32/42659_2.png) [@avinash-choudhary](https://discourse.nodered.org/u/avinash-choudhary)\
**Post date:** [18 June 2021 12:32 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/3 "2021-06-18T12:32:53Z")

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Hi @edje11  
I am able to use same COM port in two flows and getting output for both the flows.

 ![Screenshot 2021-06-17 at 11.21.48 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/e/f/ef2ec5a2becd20e33208843648c7a80e6f7bc2d3.png)  
 ![Screenshot 2021-06-17 at 11.21.52 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/3/739fad492dda55926025c893d08134cd51a4b56f.png)  
 ![Screenshot 2021-06-17 at 11.21.58 AM](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/f/a/fa26bb56cd1955edf7a859a34777eec8ad255d80.png)

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**Author:** ![knolleary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/knolleary/32/3_2.png) [@knolleary](https://discourse.nodered.org/u/knolleary)\
**Post date:** [18 June 2021 13:19 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/5 "2021-06-18T13:19:15Z")

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@avinash-choudhary please do not ping individual forum members.

What you describe sounds like a bug in the node. Disabling one of the serial nodes should not break the other one. Please raise an issue in the [node-red-nodes](https://github.com/node-red/node-red-nodes/issues) repository.

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [18 June 2021 13:58 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/6 "2021-06-18T13:58:33Z")

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Seems to work fine for me on Linux - not sure what you are doing with Postman - are you disabling the tab or just the node ? And you are re-deploying in between times ? If I disable/enable in the editor it works fine (for me).

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**Author:** ![avinash-choudhary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/avinash-choudhary/32/42659_2.png) [@avinash-choudhary](https://discourse.nodered.org/u/avinash-choudhary)\
**Post date:** [19 June 2021 11:56 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/7 "2021-06-19T11:56:35Z")

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@knolleary  
Sure noted , wont include individual next time.  
Ya will raise a bug

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<div class="post-metadata">

**Author:** ![avinash-choudhary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/avinash-choudhary/32/42659_2.png) [@avinash-choudhary](https://discourse.nodered.org/u/avinash-choudhary)\
**Post date:** [19 June 2021 12:06 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/8 "2021-06-19T12:06:23Z")

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Hi @dceejay

I am Creating Flow1 and Flow 2 from Postman with the api:  
[https://nodered.org/docs/api/admin/methods/post/flow](https://nodered.org/docs/api/admin/methods/post/flow)

Disable and enable FLOW2 from postman using API:  
[https://nodered.org/docs/api/admin/methods/put/flow](https://nodered.org/docs/api/admin/methods/put/flow)

After this Flow1 Serial Port COM2 stops displaying the debug message though connected.

Have Attached the api's i have used  
[Node RED Serial Port.postman\_collection.json](https://discourse.nodered.org/uploads/short-url/uBSpnrd8swlP41n9857xA7BsQDL.json) (4.6 KB)

Thanks,  
Avinash

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<div class="post-metadata">

**Author:** ![avinash-choudhary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/avinash-choudhary/32/42659_2.png) [@avinash-choudhary](https://discourse.nodered.org/u/avinash-choudhary)\
**Post date:** [23 June 2021 09:29 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/9 "2021-06-23T09:29:43Z")

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Hi @dceejay

Where u able to run the postman api ?  
was the error reproducible ?

Thanks,  
Avinash

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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:** [22 August 2021 09:30 UTC](https://discourse.nodered.org/t/same-serial-port-connected-in-two-flow-files-not-working/47274/10 "2021-08-22T09:30:07Z")

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