How to establish Node Red RS 485 Modbus RTU to connect to Energy Meter?

Step 1

I change the Serial Port from Default RS232 to RS485 in iot2000setup 

Step 2

In Node Red

I add the Serial Input and set Baud Rate, But  I cannot get any input at all.

Please Suggest.

Thank you.

Nitasana

Hi iSanto,

Modbus is a master /slave communication and in this instance you are the master and as such you have to initiate the communication.

You will need to install a Modbus node in Node-Red set that up and should then be able to communicate.

If you have already done the above provide more detail on the problem and it might be easier to get an answer.

Kind Regards,

Johann

Dear Nitasana,

Modbus RTU  can not be achieve with simple node red serialport library.

Plz follow the below steps

1) Connect X2 P1 port to internet line to install below node red nodes.

Make sure you have a working internet connection (LAN or WIFI).

Open commandline and enter:

2) npm install node-red-node-serialport

after successful installation of serial port install node-gyp

3) npm -g install node-gyp

Sets IOT2000 actual date and time (important for compiling)

4) date -s "21 DEC 2017 17:00:00"

After changing date and time install Mobdus node globally.

5) npm install -g node-red-contrib-modbus

after successful installation of Modbus RTU then reboot the system

6) reboot

Open commandline and enter:

7) " IOT2000Setup " to assign X30 COm as RS485 port and use pin 1 & 2 for connector 

Start the node red server and open the web page for modbus configuration.

Follow the steps as per attached video.

Good luck!!!!!!!!!!!!

 Hie to all 

 I am also trying to do the modbus RTU communication  with IOT 2040, 

I have done all settings as described but still i am not getting Modbus RTU block as shown in the video.

Can any one can guide me how to get it or how to establish the communication.

Thanks in advance

Javed Akhtar

DJ_1

Dear Nitasana,

Modbus RTU  can not be achieve with simple node red serialport library.

Plz follow the below steps

1) Connect X2 P1 port to internet line to install below node red nodes.

Make sure you have a working internet connection (LAN or WIFI).

Open commandline and enter:

2) npm install node-red-node-serialport

after successful installation of serial port install node-gyp

3) npm -g install node-gyp

Sets IOT2000 actual date and time (important for compiling)

4) date -s "21 DEC 2017 17:00:00"

After changing date and time install Mobdus node globally.

5) npm install -g node-red-contrib-modbus

after successful installation of Modbus RTU then reboot the system

6) reboot

Open commandline and enter:

7) " IOT2000Setup " to assign X30 COm as RS485 port and use pin 1 & 2 for connector 

Start the node red server and open the web page for modbus configuration.

Follow the steps as per attached video.

Good luck!!!!!!!!!!!!

Hie

Now i have formatted the MMC card and install all libraries once again.

Now mod bus related libraries are visible , and i used the same in my program but its continuously giving  error as

"TypeError: Cannot read property 'registerForModbus' of null"

From a clean install of the V2.2 image, I found the following worked:

npm install -g node-red-contrib-modbus@3.6.1 --unsafe-perm --build-from-source

(I don't know if --unsafe-perm --build-from-source are really needed)

I think there was a change in later versions of contrib-modbus that are incompatible with node.js V6 which the image currently has. I believe this will be updated in the V2.4 image.

Steve

 Worked like a charm. Much thanks!

squirest

From a clean install of the V2.2 image, I found the following worked:

npm install -g node-red-contrib-modbus@3.6.1 --unsafe-perm --build-from-source

(I don't know if --unsafe-perm --build-from-source are really needed)

I think there was a change in later versions of contrib-modbus that are incompatible with node.js V6 which the image currently has. I believe this will be updated in the V2.4 image.

Steve

I am probably just being silly but I couldn't find any video in your answer to check how I will use the tools installed. The only attachment I found was a .exe file since I am using Debian I wasn't able to open it... but anyway, it is not a video file. Where is the video that is mentioned in the answer, could you help me with this silly problem?

Thank you so much in advance!