# Modbus-contrib tcp/ip fails

**URL:** <https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163>\
**Category:** General\
**Created:** [2 February 2020 08:30 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163 "2020-02-02T08:30:18Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![iTzMentats](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@iTzMentats](https://discourse.nodered.org/u/iTzMentats)\
**Post date:** [2 February 2020 08:30 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163/1 "2020-02-02T08:30:18Z")

</div>

Hi everyone 🙂

first of all sorry if my english is not going to be perfect, but I'm from Italy.

I'm having some troubles with modbus-contrib by @bianco-royal .  
Basically, the connection to the server is ok, but I'm not able to read or write anything.

I've already tried a TCP-RESPONSE node injecting an hex buffer, and everything works good.  
From the tcp/ip to rs485 device I can clearly see two connections from my client, just to be sure that it isn't a tcp-part problem.

I hope someone can help me..

Have a good day 😃

Here is my temporary flow:

```auto
[{"id":"dda328e3.b92f48","type":"tab","label":"Modbus -video Flow 1","disabled":false,"info":""},{"id":"d0aa07e1.8888e8","type":"modbus-read","z":"dda328e3.b92f48","name":"","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"","dataType":"HoldingRegister","adr":"6","quantity":"1","rate":"3","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"d0e85f54.82355","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":210,"y":80,"wires":[["776f16c7.659548"],[]]},{"id":"776f16c7.659548","type":"debug","z":"dda328e3.b92f48","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":440,"y":80,"wires":[]},{"id":"11acc744.0ef1a9","type":"inject","z":"dda328e3.b92f48","name":"unit address","topic":"","payload":"00 03 00 06 00 01 65 DA","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":180,"wires":[["eec4ff8b.d0f49"]]},{"id":"eec4ff8b.d0f49","type":"function","z":"dda328e3.b92f48","name":"","func":"bufferInput = msg.payload.replace(/\\s/g, '');\nmsg.payload = Buffer.from(bufferInput, \"hex\");\nreturn msg;","outputs":1,"noerr":0,"x":350,"y":180,"wires":[["bc01da87.1739a8"]]},{"id":"bc01da87.1739a8","type":"tcp request","z":"dda328e3.b92f48","server":"10.0.1.168","port":"8233","out":"sit","splitc":" ","name":"","x":540,"y":180,"wires":[["12ea9d53.4ed583"]]},{"id":"12ea9d53.4ed583","type":"debug","z":"dda328e3.b92f48","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":780,"y":180,"wires":[]},{"id":"d0e85f54.82355","type":"modbus-client","z":"","name":"","clienttype":"tcp","bufferCommands":true,"stateLogEnabled":false,"tcpHost":"10.0.1.168","tcpPort":"8233","tcpType":"TPC-RTU-BUFFERED","serialPort":"/dev/ttyUSB","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","unit_id":"1","commandDelay":"1","clientTimeout":"3000","reconnectTimeout":"2000"}]

```

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<div class="post-metadata">

**Author:** ![biancode](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/biancode/32/16700_2.png) [@biancode](https://discourse.nodered.org/u/biancode)\
**Post date:** [3 February 2020 07:31 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163/2 "2020-02-03T07:31:34Z")

</div>

please, test these settings:

```auto
[{"id":"f2f57786.3439c8","type":"tab","label":"Modbus -video Flow 1","disabled":false,"info":""},{"id":"9c343fbe.0551b","type":"modbus-read","z":"f2f57786.3439c8","name":"","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"","dataType":"HoldingRegister","adr":"6","quantity":"1","rate":"3","rateUnit":"s","delayOnStart":true,"startDelayTime":"","server":"4d99eaf7.d28854","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":230,"y":80,"wires":[["c7fb49a0.bc5f68"],[]]},{"id":"c7fb49a0.bc5f68","type":"debug","z":"f2f57786.3439c8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":440,"y":80,"wires":[]},{"id":"cbb9c11f.959ed","type":"inject","z":"f2f57786.3439c8","name":"unit address","topic":"","payload":"00 03 00 06 00 01 65 DA","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":180,"wires":[["95602a1e.efad18"]]},{"id":"95602a1e.efad18","type":"function","z":"f2f57786.3439c8","name":"","func":"bufferInput = msg.payload.replace(/\\s/g, '');\nmsg.payload = Buffer.from(bufferInput, \"hex\");\nreturn msg;","outputs":1,"noerr":0,"x":350,"y":180,"wires":[["75c850b5.a4ae48"]]},{"id":"75c850b5.a4ae48","type":"tcp request","z":"f2f57786.3439c8","server":"10.0.1.168","port":"8233","out":"sit","splitc":" ","name":"","x":540,"y":180,"wires":[["d113cdf3.10c938"]]},{"id":"d113cdf3.10c938","type":"debug","z":"f2f57786.3439c8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":780,"y":180,"wires":[]},{"id":"4d99eaf7.d28854","type":"modbus-client","z":"","name":"","clienttype":"tcp","bufferCommands":true,"stateLogEnabled":true,"tcpHost":"10.0.1.168","tcpPort":"8233","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","unit_id":"1","commandDelay":"1","clientTimeout":"3000","reconnectOnTimeout":false,"reconnectTimeout":"2000","parallelUnitIdsAllowed":false}]

```

RTU-BUFFERED is not often supported on TCP it is more a Serial feature - mostly it should work with the default settings ...

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<div class="post-metadata">

**Author:** ![biancode](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/biancode/32/16700_2.png) [@biancode](https://discourse.nodered.org/u/biancode)\
**Post date:** [3 February 2020 07:47 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163/4 "2020-02-03T07:47:25Z")

</div>

to start playing with modbus local you can use Menu -\> Import ...

 ![grafik](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/9/1/91a1c8085e474443f8f5cd663c567175484fe9bd.png)

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<div class="post-metadata">

**Author:** ![iTzMentats](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@iTzMentats](https://discourse.nodered.org/u/iTzMentats)\
**Post date:** [4 February 2020 09:49 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163/6 "2020-02-04T09:49:12Z")

</div>

Sorry, I was without internet.  
Anyway I tried your flow, and it doesn't work anyway...  
I'm really stuck with this.

Thank you so much for the reply.

---

<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:** [4 April 2020 10:03 UTC](https://discourse.nodered.org/t/modbus-contrib-tcp-ip-fails/21163/7 "2020-04-04T10:03:45Z")

</div>

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