RS485 3Relay boards and PI

L

lnap

New member
Running into a bit of a problem, and assume it's something I've missed or misconfigured. Any help or guidance on this would be greatly appriciated.

I have a fresh install on a PI 4, one 3Relay HAT directly on the GPIO with the RX and TX dip switches turned on, I2C turned on, Serial off for shell and on for hardware. Basic 3relind install as per the wiki:
git clone https://github.com/SequentMicrosystems/3relind-rpi.git
cd 3relind-rpi/
sudo make install
Click to expand...

Configured the master HAT with:
3relind 0 cfg485wr 0 38400 1 0 1
3relind cfgmbwr 38400 0 1
Click to expand...

Slave HAT with:
3relind 1 cfg485wr 1 38400 1 0 1
Click to expand...

Slave HAT as the terminator turned on as well as ID 1 (I've also tried ID 2) without any love.

However I can only see the directly attached HAT when I list out devices through 3relind:
1727276483761.png
I'm showing the serial devices expected as well, just unsure of what to try or do now.
1727276569066.png

Thanks in advance
 
alexburcea

alexburcea

Moderator
Staff member
How did you try to communicate with the external cards? I hope you use the modbus command options like "3relind <address> mtest"
The -list command will list only the cards connected to I2C (plugged directly into the Raspberry).
The modbus Address (for the slave) is computed by adding the address settings with the dipswitch value so if you set the address to 1 and the dipswitches are configured to 1, the modbus address will be 2.
 
L

lnap

New member
alexburcea said:
How did you try to communicate with the external cards? I hope you use the modbus command options like "3relind <address> mtest"
The -list command will list only the cards connected to I2C (plugged directly into the Raspberry).
The modbus Address (for the slave) is computed by adding the address settings with the dipswitch value so if you set the address to 1 and the dipswitches are configured to 1, the modbus address will be 2.
Click to expand...
Thanks Alex! So I wasn't aware that the address needed to be added together for mtest to function correctly. That was all it is. Looks like com is working as expected, just a mistake on my part. Thanks for the clarification on the -list command too.
 
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