AdvancedHMI Software

General Category => Support Questions => Topic started by: neptun2002 on September 22, 2014, 08:57:11 AM

Title: how to deal withe many MODBUS devices on the same Com Port ?
Post by: neptun2002 on September 22, 2014, 08:57:11 AM

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

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: Archie on September 22, 2014, 09:07:11 AM

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.

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: pk on December 21, 2022, 01:12:11 AM

Hi

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

Thanks

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: frank222 on September 26, 2023, 01:53:55 PM

Hi Archie

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

Thanks

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: Archie on September 26, 2023, 03:07:23 PM

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.

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: tecnico_ably_it on February 28, 2024, 08:14:01 AM

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.

Title: Re: how to deal withe many MODBUS devices on the same Com Port ?
Post by: Archie on February 28, 2024, 08:44:13 AM

Quote from: tecnico_ably_it on February 28, 2024, 08:14:01 AM

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.