# Not possible to communicate via com port with rfxcom
**URL:** https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909
**Category:** General
**Created:** [30 July 2018 21:06 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909 "2018-07-30T21:06:02Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@koentje84](https://discourse.nodered.org/u/koentje84)
#### Post date: [30 July 2018 21:06 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/1 "2018-07-30T21:06:02Z")
Hi,
I have an issue when I wan to use the node-red-contribit-rfcom node. It doesn't want to communicate with the RFXcom device.
It complains over ReadIOCompletion.
If I use the software that comes with the RFXcom everything works. But nod in Node-red.
I'm running node red on an win7 64bit VM-ware machine.
---
### Author:  [@ukmoose](https://discourse.nodered.org/u/ukmoose)
#### Post date: [30 July 2018 21:13 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/2 "2018-07-30T21:13:33Z")
Do you mean node-red-contrib-rfxcom?
If so I'm not sure the author is on the forum very much. It's probably better to open up an issue on the guthub page for the node, [https://github.com/maxwellhadley/node-red-contrib-rfxcom/issues](https://github.com/maxwellhadley/node-red-contrib-rfxcom/issues)
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### Author:  [@krambriw](https://discourse.nodered.org/u/krambriw)
#### Post date: [31 July 2018 03:58 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/3 "2018-07-31T03:58:11Z")
Remember, you have to be sure that the other software (RFXmngr???) is really closed, otherwise the COM3 cannot be accessed from Node-RED
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### Author:  [@koentje84](https://discourse.nodered.org/u/koentje84)
#### Post date: [31 July 2018 06:21 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/4 "2018-07-31T06:21:22Z")
sorry for the typo Ukmoose.
I indeed mean node-red-contrib-rfxcom. But it can also be an issue related to serialport. Because that node also comes with the installation of node-red-contrib-rfxcom.
At this moment I have no clue where to look for and I was wondering if anyone has some experience with these kind of issues.
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### Author:  [@koentje84](https://discourse.nodered.org/u/koentje84)
#### Post date: [31 July 2018 06:22 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/5 "2018-07-31T06:22:24Z")
I already double checked that Krambriw. And the RFXmngr is really closed.
Anyway, thanks for the tip.
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### Author:  [@koentje84](https://discourse.nodered.org/u/koentje84)
#### Post date: [31 July 2018 21:44 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/6 "2018-07-31T21:44:49Z")
I have found the code that throws the error. The error comes from serialport.(serialport\_win.cpp)
```
> void __stdcall ReadIOCompletion(DWORD errorCode, DWORD bytesTransferred, OVERLAPPED* ov) {
> ReadBaton* baton = static_cast(ov->hEvent);
>
> if (errorCode) {
> ErrorCodeToString("Reading from COM port (ReadIOCompletion)", errorCode, baton->errorString);
> baton->complete = true;
> return;
> }
```
Now I only need to find out why this error occurs. Anyone suggestions?
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### Author:  [@maxwellhadley](https://discourse.nodered.org/u/maxwellhadley)
#### Post date: [28 September 2018 21:18 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/7 "2018-09-28T21:18:18Z")
Are you still having problems? There was an update of the underlying node-rfxcom module to use the (then) latest Serialport module version 6.x.x on 8th July, which may have fixed this issue, as it looks like a Serialport problem. Try updating `node-red-contrib-rfxcom`, which should pull the latest versions in
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### Author:  [@koentje84](https://discourse.nodered.org/u/koentje84)
#### Post date: [2 October 2018 21:52 UTC](https://discourse.nodered.org/t/not-possible-to-communicate-via-com-port-with-rfxcom/1909/8 "2018-10-02T21:52:41Z")
Hi Max,
Thanks for your reply.
Currently I’m running node red on an old pi. But I will definitely update the `node-red-contrib-rfxcom` see if there is any improvement/change on the situation.
I will let you know if anything is changed.