Hi,

I need urgent help. 

I'm trying to move a flow that is running on a linux pc to IOT2040. 

This flow uses the "node-red-contrib-modbus" nodes to read some data from a Siemens Pac3100.

When the flow runs on IOT's node-red, the node keep trying to reconnect after a timeout.

If I change the node to the "Modbus-Serial In" node I have got an active status but no data.

How can I make the modbus comm work with node red?

What I already did:

0 - Created a new flow on linux pc to test 10 holding registers with a modbus slave simulator

1 - Migrated this new flow to siemens iot2040

3 - As the flow is not working I changed the ports mode to Rs232 on iot2000setup and checked with switchserialmode, so I may  test it with a modbus simulator with a pc and a usb/serial converter.

4 - reinstalled the nodes using --build-from-source

5-changed the "node-red-contrib-modbus" to "Modbus-Serial-In"

There are some prints on file.

Thank you.

Yes.

I've followed this link:

https://support.industry.siemens.com/tf/WW/en/posts/how-to-establish-node-red-rs-485-modbus-rtu-to-connect-to-energy-meter/181907?page=0&pageSize=10

This morning I've tested also with Python serial. Iot was running the python script writing on x30 (/dev/ttryS2 - forever loop) the value 41.

Using a Usb/Rs232 cable with putty as hyperTerminal sniffing the port I could see nothing.

I'm asking myself if there is something wrong with my image (2.2.0) or something wrong with the hardware.

update: I've downgrade the so image from 2.2 to 2.1, now at least the modbus tcp is working. The modbus tcp was not working on 2.2. 

update 2: I've received the bad news that Siemens does not support IOT from hot line, even if your doubt is about hardware. I oppened a support call to make sure how to verify my x30 port, on hardware level, and will not receive an answer.

Hi,

Sorry I did not see your answer on that date. In contact with Siemens's hotline the suspect is that could be something wrong with the hardware. There was about 2.7V ac between pin 5 from IOT's ports and my usb/serial cable.

As I could not wait on that date I used a serial/eth converter to make the connection.