Open ttyr0 port under linux

[John245]

beerygaz

I can read the data on port /dev/ttyS0 using Node-RED, Modpoll. However your plug-in indicates unreachable.

As this is a test environment migrated from Windows nothing is changed.

Any idea how to fix?

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John

[John245]

Curious what are you using the Moxa serial servers for?

3 x PV inverter
Heating Pump
audio and video equipment

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John

[Pete]

Curious what are you using the Moxa serial servers for?

[John245]

I am not familiar with the ModBus-Pi and never have utilized a Moxa serial server.

Thinking I paid some $20 for the 1 watt LoRa serial modems mentioned above (from China) which appear to be similiar to the Moxa serial server.

Each modem has an RS-232 port on it.

The Moxa's one are good. Even better than the VSCOM devices. Issues that I had with the VSCOM devices I did never see after the switch to Moxa.

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John

[Pete]

I am not familiar with the ModBus-Pi and never have utilized a Moxa serial server.

Thinking I paid some $20 for the 1 watt LoRa serial modems mentioned above (from China) which appear to be similiar to the Moxa serial server.

Each modem has an RS-232 port on it.

[John245]

How are you connecting the hardware serial device to the RPi? Are you connecting directly to the RPi pins to a TTL to RS-232 device?

Googling read that a Rocket Port modem RS-232 connection would appear as a ttyRX connection under dev.

To be clear.

I i'm running Ubuntu 20.04 LTS in a VM. Hardware connected using a Moxa Serial server.

Moxa solved the ttyr0 ttyS0 issue.

At least it is working in Node-Red, but not in the Modbus-PI.

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John

[Pete]

How are you connecting the hardware serial device to the RPi? Are you connecting directly to the RPi pins to a TTL to RS-232 device?

Googling read that a Rocket Port modem RS-232 connection would appear as a ttyRX connection under dev.

[John245]

Testing the PI under Linux. The serial interfaces that I can select for example is /dev/ttyS0. However the data is on Port ttyr0.

Running under Ubuntu 20.04 LTS.

How can this be solved?

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John