Configuration relay board type R421A08 - RS485 MODBUS RTU

Luca_Gibin · December 24, 2018, 10:29am

Greetings to the community.

I opened this topic to ask you for help configuring the relay board R421A08

My configuration:
raspberry pi2,

and this USB to RS485 adapter

(This adapter works well with raspberry + hassio because I use it to read energy consumption data from an EASTRON SDM220-MODBUS.

)

I did some tests and I could not make the R421A08 relay card work.
I used “Modbus Switch” but I did not succeed.

On the web I found this that could help us:

https://forum.logicmachine.net/showthread.php?tid=1403

Some of you much more expert than me could help me, with the code to be written?
Thank you very much.

nickrout · December 25, 2018, 8:42am

Install the GitHub code
Control via command line component.

Luca_Gibin · December 25, 2018, 8:55am

Thanks for the reply but I still can not understand what I have to do. Could you help me?

c.man · December 26, 2018, 10:16pm

I follow…

Luca_Gibin · January 1, 2019, 9:45am

I tried to do a lot of tests.
I changed the register, but I’ve never been successful.

For the register I followed these links:

github.com

gianfrdp/SDM120C/blob/master/sdm120c.py

#!/usr/bin/python

import minimalmodbus

rs485 = minimalmodbus.Instrument('/dev/ttyUSB0', 1)
rs485.serial.baudrate = 9600
rs485.serial.bytesize = 8
rs485.serial.parity = minimalmodbus.serial.PARITY_NONE
rs485.serial.stopbits = 1
rs485.serial.timeout = 1
rs485.debug = False
rs485.mode = minimalmodbus.MODE_RTU
print rs485

Volts = rs485.read_float(0, functioncode=4, numberOfRegisters=2)
Current = rs485.read_float(6, functioncode=4, numberOfRegisters=2)
Active_Power = rs485.read_float(12, functioncode=4, numberOfRegisters=2)
Apparent_Power = rs485.read_float(18, functioncode=4, numberOfRegisters=2)
Reactive_Power = rs485.read_float(24, functioncode=4, numberOfRegisters=2)
Power_Factor = rs485.read_float(30, functioncode=4, numberOfRegisters=2)

This file has been truncated. show original

https://forum.logicmachine.net/showthread.php?tid=1403

Some registers are in the comments.

What am I doing wrong?
I saw that the communication LED sometimes flashes.
This is the last code loaded:

modbus:
  type: serial
  method: rtu
  port: /dev/ttyUSB0
  baudrate: 9600
  stopbits: 1
  bytesize: 8
  parity: N


switch:
  platform: modbus
  slave: 1
  coils:
    - name: R1
      slave: 1
      coil: 40101
    - name: R2
      slave: 1
      coil: 40002
  registers:
    - name: R3
      slave: 1
      register: 40002
      command_on: 1
      command_off: 0
    - name: R4
      slave: 1
      register: 40003
      command_on: 1280
      command_off: 0
    - name: R5
      slave: 1
      register: 40104
      command_on: 01
      command_off: 00
    - name: R6
      slave: 1
      register: 01
      command_on: 1
      command_off: 0

Please can someone help me?
Thank you very much.

ruiazevedo · February 5, 2019, 10:29am

I have the same problem.
Has anyone got the solution?
This equipment accect function Preset Multiple Registers (FC=16), but the HA write registers whith de function Preset Single Register (FC=06).
Has anyone know implement this function in HA?

ruiazevedo · February 19, 2019, 2:51pm

I found a solution that works but I do not get feedback from the relay module.

I wrote a script in python, which uses the mobuspy and is called by a button in the homeassistantt with command line.
My file calls 8O.py, and the id RS485 is 7.

My scripy in python:
#!/usr/bin/python

#---------------------------------------------------------------------------# 
# import the various server implementations
#---------------------------------------------------------------------------# 
from pymodbus.client.sync import ModbusTcpClient as ModbusClient
# from pymodbus.client.sync import ModbusSerialClient as ModbusClient
from pymodbus.transaction import ModbusRtuFramer as ModbusFramer
#---------------------------------------------------------------------------# 
# configure the client logging
#---------------------------------------------------------------------------# 
import logging
import sys

# parametros de entrada
relay = int(sys.argv[1])
value = int(sys.argv[2])

logging.basicConfig()
log = logging.getLogger()
log.setLevel(logging.DEBUG)
#Define Modbus Target Device
client = ModbusClient(host='192.168.1.10',port=502)
connection = client.connect()
print (connection)
# send write command to modbus server
#600= off 300 = on
register_value = client.write_register(relay, value, unit= 7)
client.close()

#---------------------------------------------------------------------------#

In configuration.yaml:

platform: command_line
switches:
switch_1:
command_on: ‘python3 /config/8O.py 1 300’
command_off: ‘python3 /config/8O.py 1 600’

nickrout · February 19, 2019, 9:14pm

Please please follow the instructions at he top of the page and format your code properly.

vornez · September 7, 2019, 2:04am

Windows application for STM8S103 & R421A085 module

Use this utility to toggle the relay settings. Ideal for Windows 7.

Written in MS Visual Studio WIN32 C++.

https://sourceforge.net/projects/rs485modbus/

nickrout · September 7, 2019, 2:07am

What has this to do with home assistant?

alleonname · January 25, 2020, 10:01am

For 4 channel 4CH Modbus RTU relay module 4 ch relay module rs485
In configuration.yaml:

modbus:
  - type: serial
    name: hubrelay
    method: rtu
    port: /dev/ttyUSB1
    baudrate: 9600
    stopbits: 1 
    bytesize: 8
    parity: N
    timeout: 1
    
switch:
  - platform: modbus
    registers:
      - name: Relay1 
        hub: hubrelay
        slave: 1
        register: 1
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay2 
        hub: hubrelay
        slave: 1
        register: 2
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay3 
        hub: hubrelay
        slave: 1
        register: 3
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay4 
        hub: hubrelay
        slave: 1
        register: 4
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0

Wupsman · December 12, 2020, 8:07pm

Thanks alleonname for sharing your configuration with us, it worked right away for me with the R4D3B16:

modbus:
  - type: serial
    name: hubrelay
    method: rtu
    port: /dev/ttyUSB0
    baudrate: 9600
    stopbits: 1 
    bytesize: 8
    parity: N
    timeout: 1
    
switch:
  - platform: modbus
    registers:
      - name: Relay1 
        hub: hubrelay
        slave: 1
        register: 1
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay2 
        hub: hubrelay
        slave: 1
        register: 2
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay3 
        hub: hubrelay
        slave: 1
        register: 3
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay4 
        hub: hubrelay
        slave: 1
        register: 4
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay5
        hub: hubrelay
        slave: 1
        register: 5
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay6
        hub: hubrelay
        slave: 1
        register: 6
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay7
        hub: hubrelay
        slave: 1
        register: 7
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay8
        hub: hubrelay
        slave: 1
        register: 8
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0 
      - name: Relay9
        hub: hubrelay
        slave: 1
        register: 9
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay10
        hub: hubrelay
        slave: 1
        register: 10
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay11
        hub: hubrelay
        slave: 1
        register: 11
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay12
        hub: hubrelay
        slave: 1
        register: 12
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay13
        hub: hubrelay
        slave: 1
        register: 13
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay14
        hub: hubrelay
        slave: 1
        register: 14
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay15
        hub: hubrelay
        slave: 1
        register: 15
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0
      - name: Relay16
        hub: hubrelay
        slave: 1
        register: 16
        command_on: 256
        command_off: 512
        state_on: 1
        state_off: 0

galle · December 18, 2020, 5:48pm

hi i bought a modbus RTU relay (WAVESHARE).
i installed usb adapter in a raspb (it should be recognized directly as i read in posts.
to activate realay 1 I have to send a hex: 01 05 00 06 FF 00 6C 3B.
How can I do?
thanks

nickrout · December 18, 2020, 7:06pm

galle · December 18, 2020, 8:42pm

I tried to read.
But how i send a hex 01 05 00 06 FF 00 6c 3b to activate the relay?

nickrout · December 18, 2020, 8:51pm

Are you sure this is modbus?

galle · December 18, 2020, 9:09pm

Yes.
I use “register” and “command on” but don’t work with 01 05 00 ecc.

galle · December 20, 2020, 3:14pm

I managed to activate the relays using the -call service- function:
modbus.write_coil
unit: 1
hub: hubrelay
address: 2
state: 1

but in my case -switch- and -binary sensor- of -modbus- don’t work
so I can’t read the status of the relays

nickrout · December 20, 2020, 6:49pm

What is your binary_sensor: yaml?

galle · December 20, 2020, 7:05pm

In configuratio.yalm…

binary_sensor:

platform: modbus
inputs:
- name: Sensor1
  hub: hubrelay
  slave: 1
  address: 3

a function as well as read coil?