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Modbus TCP

Ignore AC input over modbus / dbus?

I am looking for a way to just ignore the AC input.

I have modbus tcp and access to the dbus thru nodered, but I dont see how i would change that setting.

Currenlty i overwrite the settings manually every day with VEConfigure, but that is pretty painfull. :)

How can I achieve this and make some nice flows in nodered?

betz asked
jacola answered ·

3 Answers

VenusGX + Node-RED - Modbus TCP Communication Issues

Hello,

I have installed the recent VenusGX v2.42 FW build with integrated Node-RED from https://github.com/victronenergy/venus/issues/378.

I am trying to communicate with an external device via Modbus TCP (a My PV AC Thor - which is a modulated AC heater power control unit) and control it via logic developed within Node-RED.

I have successfully installed the additional contrib node 'node-red-contrib-modbustcp' https://flows.nodered.org/node/node-red-contrib-modbustcp and am able to communicate with the unit.

However I'm unable to setup a flow to BOTH write to the unit (with a power request) at regular intervals AND read from any registers (such as temperature) at regular intervals.


For example;

Write only - connects/works fine

[image]


Write & Read - no connection

[image]

[image]


Write & Read after a few minutes - write connects/works but read doesn't

[image]


Read only (write node deleted) - connects/works fine

[image]


I do know that a Modbus TCP read and write event can't occur exactly simultaneously (and it doesn't need to), but I'm not sure how to sequence the read/write requests or what I can change to get this working with the Modbus TCP node-set that I'm currently using...


My next step was to attempt installing a different / mode advanced Modbus contrib node 'node-red-contrib-modbus' https://flows.nodered.org/node/node-red-contrib-modbus (I have seen examples of write and read nodes successfully coexisting with this node-set) but unfortunately I get a bunch of installation errors - see below;

[image]


I have also tried to install https://flows.nodered.org/node/node-red-contrib-modbus manually via Putty using the npm install command (including the suggested variations) but still get the similar errors.

[image]


My programming/Linux skills are very limited, so troubleshooting this myself is a bit beyond me.


If anyone is able to offer some advice on how I can possibly get write and read communication working with the current Modbus node-set I'm using (https://flows.nodered.org/node/node-red-contrib-modbustcp) or how to get the more advanced Modbus node-set (https://flows.nodered.org/node/node-red-contrib-modbus) successfully installed on the VenusGX it would be greatly appreciated.


PS. I do know that my other option is to run node-red externally to the VenusGX unit (such as on a RPi), but I want to leave this as a last option for now.


Thanks in advance, Mark.

Mark asked
shaun commented ·

1 Answer

Get data from my Victron Venus to my Node-Red ...

Hi all,

I would really like to get any kind of data from my Venus GX into my RPi Node-Red Installation.


What I tried so far:

Modbus ... unfortunately it is not possible to read data from Node-Red using the Modbus Nodes like that:

[image]

[image]

Although the reference guide tells me: Address 800 - length 6 --> Serial number



Second I tried to use the existing Victron Nodes - I added the Environment line as explained in the instructions:

                  
  1. Environment="NODE_RED_DBUS_ADDRESS=10.0.0.169:78"

But still the Victron-Nodes are empty ... no connection to my Venus seem to be possible:

[image]

[image]


and thats a pitty, because I really would like to see at least ANYTHING :( :( :(

Please help me ...

BR

Gawan

gawan asked

0 Answers

Controlling TriStar diversion controller over Modbus

Hi,

I'm planning my off-grid system. The main issue I have is the AC coupled wind inverter which doesn't support frequency shifting.

[image]

In order to protect the batteries from overcharging my plan is to use Morningstar Tristar PWM in diversion mode.

Unfortunately it doesn't support communication with BYD's BMU. I hope it's possible to use Modbus communication and send to it charging parameters from the Venus OS (node-red).

It will allow TriStar to dynamically divert excess power and keep the batteries happy ;)


Do you think it's possible?

Thanks for your help ;)

dyju711 asked
dyju711 answered ·

1 Answer

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