Modbus 485 no connection

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wstarzl
Posts: 5
Joined: 18 Jan 2022, 15:40

Modbus 485 no connection

Post by wstarzl »

The problem is that we have no connection from the RS 485 bus to the Revolution PI 32GB with the PIctory (v2.0.4) configuration file.
For the older version of pictory (such as v1.4.x),
, we usually set the “action interval(ms)” to 2000 ms, and works well, but in this version (v2.0.4), 2000ms cannot work, then I modified it back to 1000ms , now it can work, is this a bug?
or how can i find the perfect working Action Intervall time (ms)?

Thanks and best regards!
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nicolaiB
KUNBUS
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Joined: 21 Jun 2018, 10:33
Location: Berlin
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Re: Modbus 485 no connection

Post by nicolaiB »

Hi wstarzl,

do you see any error messages in Pictory? Do you use a modbus master or slave? Are there any error messages in the pimodbus logs?

Nicolai
wstarzl
Posts: 5
Joined: 18 Jan 2022, 15:40

Re: Modbus 485 no connection

Post by wstarzl »

nicolaiB wrote: 18 Jan 2022, 16:57 Hi wstarzl,

do you see any error messages in Pictory? Do you use a modbus master or slave? Are there any error messages in the pimodbus logs?

Nicolai
Hello Nicolai, thanks for your quick reply, we use virtual modbus-rtu master module, I haven't seen any errors in pictory, could you please tell me how to check pimodbus log?
we have 4 revpi modules in this project, yesterday I modified the interval time of No. 1 revpi from 2000 to 1000 and it worked well, but today it failed again, and another module with 2000 works very well, their configurations are almost the same, it seems that the interval time is not the problem.
btw: the OS we use for revpi is the latest Buster.
Best regards!
wstarzl
Posts: 5
Joined: 18 Jan 2022, 15:40

Re: Modbus 485 no connection

Post by wstarzl »

nicolaiB wrote: 18 Jan 2022, 16:57 Hi wstarzl,

do you see any error messages in Pictory? Do you use a modbus master or slave? Are there any error messages in the pimodbus logs?

Nicolai
Hello Nicolai,
I found the problem: after reboot, seems pictory cannot start-up automatically, only when I run the command "piTest -x", we can get the data from slaves.
My appreciation if you can teach me how to solve this.

Best regards!
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nicolaiB
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Joined: 21 Jun 2018, 10:33
Location: Berlin
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Re: Modbus 485 no connection

Post by nicolaiB »

Hi,

This is a known bug and we're about to release a fix for this. For now you can apply the fix manually as described here viewtopic.php?f=10&t=3242&p=11687#p11687

Nicolai
wstarzl
Posts: 5
Joined: 18 Jan 2022, 15:40

Re: Modbus 485 no connection

Post by wstarzl »

nicolaiB wrote: 19 Jan 2022, 08:51 Hi,

This is a known bug and we're about to release a fix for this. For now you can apply the fix manually as described here viewtopic.php?f=10&t=3242&p=11687#p11687

Nicolai
problem's fixed, thank you so much!
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