Hi
I’m attempting to control a ventilation system which supports modbus communication. I have a cheap rs485 to USB adaptor and the following configuration:
modbus:
name: mvhr
type: serial
method: rtu
port: /dev/serial/by-id/usb-FTDI_FT232R_USB_UART_AG0KB7RX-if00-port0
baudrate: 9600
stopbits: 1
bytesize: 8
parity: N
and
- platform: modbus
registers:
- name: mvhr_outside_temp
hub: mvhr
unit_of_measurement: °C
slave: 1
register: 11
and this is the modbus description from the user manual:
- Properties
Control board uses Modbus RTU protocol via RS485 connection. The unit works as Slave and the information can be taken
from an external Master module.
Connection information of the unit is listed as below:
Connection Type: Modbus RTU Slave
Standard Address: 1
Link speed: 9600
Party: None
Data Bits: 8
Stop Bit: 1
I’m not having any luck getting readings from the sensor though. It just displays unknown.
After doing a bit of reading I’ve found out that not all rs485 usb adaptors are compatible, maybe this is the problem.
Also the wall controller for the ventilation system runs on modbus too so maybe there is an address conflict. I cant find any info on the standard address for the wall controller.
Unfortunately I’m trying to do this remotely as the system isn’t at my house which makes it hard to do too much physical testing but any ideas would be much appreciated!