# Modbus serial port msg : PortNotOpenError "PortNotOpenError: Port Not Open"

**URL:** <https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899>\
**Category:** General\
**Created:** [8 April 2019 12:12 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899 "2019-04-08T12:12:32Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![hathemi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hathemi/32/3792_2.png) [@hathemi](https://discourse.nodered.org/u/hathemi)\
**Post date:** [8 April 2019 12:12 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/1 "2019-04-08T12:12:32Z")

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i'am trying to read data using serial port, but i always get this error "msg : PortNotOpenError "PortNotOpenError: Port Not Open" ". How can i fix it ??

[{"id":"fadac826.dbf338","type":"modbus-flex-getter","z":"ab90743a.06b9b8","name":"Modbus Flexible Read","showStatusActivities":false,"showErrors":true,"logIOActivities":false,"server":"afde9269.cbd15","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":618,"y":406,"wires":[["797c5709.714ef8","a550ca71.058e88","cc5f74e3.a11198"],["ecb30d00.d549d","515a9f89.d9c41"]]},{"id":"e8a6de28.e63fb","type":"inject","z":"ab90743a.06b9b8","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":238,"y":346,"wires":[["15af9210.916a6e"]]},{"id":"15af9210.916a6e","type":"function","z":"ab90743a.06b9b8","name":"FC1","func":"msg.payload = { 'fc': 1, 'unitid': 1, 'address': 0 , 'quantity': 16 }\nreturn msg;","outputs":1,"noerr":0,"x":388,"y":346,"wires":[["fadac826.dbf338"]]},{"id":"797c5709.714ef8","type":"debug","z":"ab90743a.06b9b8","name":"","active":false,"console":"false","complete":"payload","x":868,"y":306,"wires":},{"id":"ecb30d00.d549d","type":"debug","z":"ab90743a.06b9b8","name":"","active":false,"console":"false","complete":"true","x":848,"y":446,"wires":},{"id":"515a9f89.d9c41","type":"modbus-response","z":"ab90743a.06b9b8","name":"","registerShowMax":20,"x":888,"y":486,"wires":},{"id":"cc5f74e3.a11198","type":"debug","z":"ab90743a.06b9b8","name":"","active":true,"console":"false","complete":"true","x":848,"y":386,"wires":},{"id":"a550ca71.058e88","type":"debug","z":"ab90743a.06b9b8","name":"","active":false,"console":"false","complete":"responseBuffer","x":898,"y":346,"wires":},{"id":"eaf14b08.129128","type":"inject","z":"ab90743a.06b9b8","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":238,"y":386,"wires":[["5e8b0622.f6b668"]]},{"id":"5e8b0622.f6b668","type":"function","z":"ab90743a.06b9b8","name":"FC2","func":"msg.payload = { 'fc': 2, 'unitid': 1, 'address': 0 , 'quantity': 8 }\nreturn msg;","outputs":1,"noerr":0,"x":388,"y":386,"wires":[["fadac826.dbf338"]]},{"id":"730c158f.78f8ec","type":"inject","z":"ab90743a.06b9b8","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":238,"y":426,"wires":[["accaf902.ef2de8"]]},{"id":"accaf902.ef2de8","type":"function","z":"ab90743a.06b9b8","name":"FC3","func":"msg.payload = { 'fc': 3, 'unitid': 1, 'address': 0 , 'quantity': 8 }\nreturn msg;","outputs":1,"noerr":0,"x":388,"y":426,"wires":[["fadac826.dbf338"]]},{"id":"15363396.cc2b6c","type":"inject","z":"ab90743a.06b9b8","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":238,"y":466,"wires":[["695b87a1.e4c808"]]},{"id":"695b87a1.e4c808","type":"function","z":"ab90743a.06b9b8","name":"FC4","func":"msg.payload = { 'fc': 4, 'unitid': 1, 'address': 0 , 'quantity': 10 }\nreturn msg;","outputs":1,"noerr":0,"x":388,"y":466,"wires":[["fadac826.dbf338"]]},{"id":"83991e00.6596a","type":"comment","z":"ab90743a.06b9b8","name":"Flexible Read and Write","info":"","x":258,"y":286,"wires":},{"id":"afde9269.cbd15","type":"modbus-client","z":"","name":"","clienttype":"tcp","bufferCommands":true,"stateLogEnabled":false,"tcpHost":"127.0.0.1","tcpPort":"502","tcpType":"C701","serialPort":"COM6","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"7","serialStopbits":"2","serialParity":"even","serialConnectionDelay":"100","unit\_id":"11","commandDelay":"1","clientTimeout":"30000","reconnectTimeout":"2000"}]

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [8 April 2019 12:19 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/2 "2019-04-08T12:19:31Z")

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> [@hathemi](#):
>
> PortNotOpenError

Have you tried googling the error message?

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<div class="post-metadata">

**Author:** ![hathemi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hathemi/32/3792_2.png) [@hathemi](https://discourse.nodered.org/u/hathemi)\
**Post date:** [8 April 2019 13:28 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/3 "2019-04-08T13:28:54Z")

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yeah i have search alot but i get nothing useful... now i'am getting new error wich is  
" fsm reset on state empty ". How can i fixe this problem and open serial port ?

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [8 April 2019 13:31 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/4 "2019-04-08T13:31:56Z")

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If I google that error I find this page [https://github.com/biancode/node-red-contrib-modbus/issues/62](https://github.com/biancode/node-red-contrib-modbus/issues/62) .Did you not find this or have you followed the advice and it didn't make a difference?

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<div class="post-metadata">

**Author:** ![hathemi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hathemi/32/3792_2.png) [@hathemi](https://discourse.nodered.org/u/hathemi)\
**Post date:** [8 April 2019 13:36 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/5 "2019-04-08T13:36:43Z")

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> [@ukmoose](#):
>
> [Modbus connection between my PLc and node-red · Issue #62 · BiancoRoyal/node-red-contrib-modbus · GitHub](https://github.com/biancode/node-red-contrib-modbus/issues/62)

i have seen it and it didn't make a difference.

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [8 April 2019 13:45 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/6 "2019-04-08T13:45:04Z")

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So when you added the catch node it didn't display anything?

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<div class="post-metadata">

**Author:** ![hathemi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hathemi/32/3792_2.png) [@hathemi](https://discourse.nodered.org/u/hathemi)\
**Post date:** [8 April 2019 13:48 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/7 "2019-04-08T13:48:19Z")

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> [@ukmoose](#):
>
> it didn't display anything

yes exactly.

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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:** [8 April 2019 20:20 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/8 "2019-04-08T20:20:42Z")

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Have you checked the node red log to see if anything useful there? Run

```bash
node-red-stop
node-red-start

```

and post the result, starting with the node red Welcome message.

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<div class="post-metadata">

**Author:** ![hathemi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hathemi/32/3792_2.png) [@hathemi](https://discourse.nodered.org/u/hathemi)\
**Post date:** [8 April 2019 21:23 UTC](https://discourse.nodered.org/t/modbus-serial-port-msg-portnotopenerror-portnotopenerror-port-not-open/9899/9 "2019-04-08T21:23:44Z")

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ok i will try that and send you log back.  
Could be a possible way that i have to address DM200 of Omron PLC ? if so, how could i address it ?