# Serial Out node - RS232 Barcode Reader

**URL:** <https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961>\
**Category:** General\
**Created:** [15 November 2020 16:09 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961 "2020-11-15T16:09:26Z")\
**Posts on this page:** 12\
**Page:** 1

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**Author:** ![petrei86](https://avatars.discourse-cdn.com/v4/letter/p/8c91f0/32.png) [@petrei86](https://discourse.nodered.org/u/petrei86)\
**Post date:** [15 November 2020 16:09 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/1 "2020-11-15T16:09:26Z")

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Hi

Sorry for my bad english:  
Im use a Raspberry Pi (Revolution Pi) with Node-Red.

With serial\_in Node (/dev/ttyUSB0:9600-8N1), im recive the Barcodes from Barcode Reader ([https://www.delock.de/produkte/G\_90287/merkmale.html?setLanguage=en](https://www.delock.de/produkte/G_90287/merkmale.html?setLanguage=en)) -  
that works fine!

My problem:  
Sending data to the barcode reader!  
Im create injection node, send the payload {MVERRR}, but no response from barcodereader. So assume the sending did not work.

thank you for your help

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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:** [15 November 2020 16:18 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/2 "2020-11-15T16:18:15Z")

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> [@petrei86](#):
>
> send the payload {MVERRR}, but no response from barcodereader. So assume the sending did not work

Can you show how the serial node is set to send data? (on certain character? after an amount of time?

Are you using serial request node?

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**Author:** ![petrei86](https://avatars.discourse-cdn.com/v4/letter/p/8c91f0/32.png) [@petrei86](https://discourse.nodered.org/u/petrei86)\
**Post date:** [15 November 2020 17:25 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/3 "2020-11-15T17:25:08Z")

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Hi Steve-Mcl

Yes, use the serial request. Settings in Screenshot:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/5/6/56a3851174b4c7a4d391bfb040fb9ac0d30f0795.png)

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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:** [15 November 2020 17:29 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/4 "2020-11-15T17:29:36Z")

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So see where you have split char `\n` the serial request node won't output until a newline. Are you certain newlines are given out by the device?

Also, if it does use newline as a marker, it may also use newline as it's input marker. I.e. try setting add character to output message as `\n` or adding a newline `\n` to your payload.

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**Author:** ![petrei86](https://avatars.discourse-cdn.com/v4/letter/p/8c91f0/32.png) [@petrei86](https://discourse.nodered.org/u/petrei86)\
**Post date:** [15 November 2020 17:33 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/5 "2020-11-15T17:33:07Z")

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**I've tried both unsuccessfully.**  
For your information: With \ n the scans arrive successfully. But only the scanns

Development Guide from Barcodereader  
[https://www.delock.de/files/40928.download](https://www.delock.de/files/40928.download)

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**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:** [15 November 2020 18:52 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/6 "2020-11-15T18:52:12Z")

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Can you show us in a debug node what the output is from your injection node?  
Or share your flow.

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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:** [15 November 2020 18:54 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/7 "2020-11-15T18:54:58Z")

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Devices often need \r rather than \n

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<div class="post-metadata">

**Author:** ![petrei86](https://avatars.discourse-cdn.com/v4/letter/p/8c91f0/32.png) [@petrei86](https://discourse.nodered.org/u/petrei86)\
**Post date:** [15 November 2020 18:56 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/8 "2020-11-15T18:56:21Z")

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thank for your help

The flow is:`[{"id":"5d5ef21b.a6885c","type":"tab","label":"ReaderInputs","disabled":false,"info":""},{"id":"310a6d52.150c22","type":"inject","z":"5d5ef21b.a6885c","name":"SetReadMode","topic":"","payload":"{MVERRR}","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":230,"y":160,"wires":[["705398bf.ccbc08","edee5b23.ef03a8"]]},{"id":"edee5b23.ef03a8","type":"debug","z":"5d5ef21b.a6885c","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":890,"y":160,"wires":[]},{"id":"705398bf.ccbc08","type":"serial request","z":"5d5ef21b.a6885c","name":"SendAndRequest","serial":"a7dbf2e6.98de5","x":590,"y":80,"wires":[["edee5b23.ef03a8"]]},{"id":"a7dbf2e6.98de5","type":"serial-port","z":"","serialport":"/dev/ttyUSB0","serialbaud":"9600","databits":"8","parity":"none","stopbits":"1","waitfor":"","dtr":"none","rts":"none","cts":"none","dsr":"none","newline":"\\n","bin":"false","out":"char","addchar":"","responsetimeout":"10000"}]`

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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:** [15 November 2020 19:16 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/9 "2020-11-15T19:16:57Z")

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According the datasheet the scanner needs an CR+LF as terminator.  
Try **\r\n** in the **Add character to output messages** box.

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<div class="post-metadata">

**Author:** ![petrei86](https://avatars.discourse-cdn.com/v4/letter/p/8c91f0/32.png) [@petrei86](https://discourse.nodered.org/u/petrei86)\
**Post date:** [15 November 2020 20:15 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/10 "2020-11-15T20:15:30Z")

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> [@edje11](#):
>
> \r\n

It does not work

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/7/1745eec441ddb9a9fef8f0bb3e772d4d6a41b9ad.png)

**why should that actually go to the right device? /dev/ttyUSB0 - there could be several devices behind it?**

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<div class="post-metadata">

**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:** [15 November 2020 20:18 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/11 "2020-11-15T20:18:10Z")

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What if you add `\r\n` to the payload e.g...

```auto
msg.payload ="{MVERRR}\r\n"; 

```

(Remember to remove the \r\n from the config first)

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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:** [14 January 2021 20:18 UTC](https://discourse.nodered.org/t/serial-out-node-rs232-barcode-reader/35961/12 "2021-01-14T20:18:14Z")

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