how to deal withe many MODBUS devices on the same Com Port ?

[neptun2002]

Dear Archie I am trying to read tow MODBUS devices one with Station ID=100 the other one   with Station ID=101

Connected to Rs485 Bus and connected to the PC Via USB to Rs485 Converter to com5

how can I read each device with a different Station ID ??

I tried to add another ModbusRTUCom2 Driver on the same com5 with a different Station ID But always I can read the one connected to ModbusRTUCom1

it seems like the com is open and not closed after the reading / writing so the second device never get any packet is there any thing wrong that I did ??


what is your suggestion to solve this ?


Thank you so much

[Archie]

You are doing the right thing, but I never tested the driver in this scenario. I will have to try it to see if there is a bug that needs fixed.

[pk]

Hi

Any solution to read two modbus devices on the same com port?

Thanks

[frank222]

Hi Archie

Any solution to read two modbus devices on the same com port?

Thanks

[Archie]

Have you tried with the latest version 3.99y Beta ? I think using two drivers pointing to the same COM port that is an RS485 port should work.

[tecnico_ably_it]

Hi Archie,
I have tested the driver with two devices connected via a usb-Rs485 converter with polling time 100ms and time out 300;
the stable 3.99x version works correctly,
the new version (3.99xbeta4), on the other hand, always generates TimeOut errors on the controls.

[Archie]

Hi Archie,
I have tested the driver with two devices connected via a usb-Rs485 converter with polling time 100ms and time out 300;
the stable 3.99x version works correctly,
the new version (3.99xbeta4), on the other hand, always generates TimeOut errors on the controls.

This is on the list to be looked into.