RaspberryPi and Arduino Modbus RTU

2020-02-27T15:28:10.693000Z

Bifogad hat geschrieben:
I added this.
[SysCom]
Linux.Devicefile=/dev/ttyACM
There is some command to see the name of the com port but I can't remember. In my case it wasn't ttyUSB.
I also didn't need to add "portnum := COM.SysCom.SYS_COMPORT1;"
/Martin

Did you have a problem with the loss of communication between Raspberry and Arduino after the reboot?

RaspberryPi and Arduino Modbus RTU

2020-02-27T15:28:09.991000Z

I added this.

[SysCom]
Linux.Devicefile=/dev/ttyACM

There is some command to see the name of the com port but I can't remember. In my case it wasn't ttyUSB.
I also didn't need to add "portnum := COM.SysCom.SYS_COMPORT1;"

/Martin

RaspberryPi and Arduino Modbus RTU

2020-02-27T15:28:09.321000Z

I used this code

sudo nano /etc/CODESYSControl.cfg

[SysCom]
Linux.Devicefile=/dev/ttyUSB
portnum := COM.SysCom.SYS_COMPORT1;

sudo /etc/init.d/codesyscontrol restart

try it

also make sure that in the point of updating the variables you have a mode (always in the task of the bus cycle) number 2.

But this will not be the only problem with the modbus rtu

After the reboot, you will have a loss of communication between Arduino and Raspberry

I have not been able to solve this problem yet.

If you find solutions please let me know

Good luck

RaspberryPi and Arduino Modbus RTU

2020-02-27T15:28:07.364000Z

Hi everyone,

I'm using the following setup:
- Raspberrry Pi 3 as Modbus RTU Master (MODBUS_COM_Port_1)
- Arduino UNO as Modbus RTU Slave
both are connected via USB
I use ModbusSerial library for Arduino from here:

https://github.com/andresarmento/modbus ... /libraries

I tested the Arduino with qModMaster on my Windows-PC via USB port. This worked well as you can see in the screenshots. Therefore I assume that the Arduino setup and code are correct.
Further, I also assigned the RaspberryPi USB Com Port described here:

l viewtopic.php?f=21&t=6755&p=14284&hilit=modbus+rtu#p14284 l

But as you can see in the screenshot, the Modbus slave is not running (red triangle) and status of Modbus Slave is 'Bus error'.
Thank you for your help!

rKtiC

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