How to send command to rs485 Relay board

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Viewing 15 posts - 16 through 30 (of 37 total)
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  • #6363
    Avatarmanjey73
    Participant

    This relay works on Modbus RTU, just the author tried to connect it first through an Ethernet – RS485 Converter and got confused.

    • This reply was modified 6 months ago by Avatarmanjey73.
    #6365
    Avatarhethongscada62
    Participant

    Hi Mikhail,
    Yes, that is a screenshot in the last time that it was configured Modbus TCP. There are some parameters bellow
    1.Description:
      R421A08 8 channel Modbus relay module equipped with mature and stable 8-bit MCU and RS485 level communication chip,adopt standard MODBUS RTU format RS485 communication protocol. It can realize 8bit input signal detection and 8bit relay output. It can be used for digital detection or power control occasions.
     2.Features:
      1>.Support Modbus RTU protocol
      2>.Support RS485/TTL UART interface
      3>.Output indicator in multi mode
      4>.Address can be set
      5>.Support input reverse connection protection
      6>.Relay switch output
      7>.Support parameter memory function
     
    3.Parameters:
      1>.Item name: 8CH Modbus Relay Module 
      2>.Work voltage:DC 12V
      3>.Baud rate:9600bps
      4>.Set address:0x01~0x3F
      5>.Delay time: 0~255s 
      6>.Load: AC 250V 10A or DC 28V 10A
      7>.Protocol:Modbus RTU
      8>.Interface:RS485/TTL UART
      9>.Control channel: 8channel
      10>.Operating Temperature:-20℃~85℃
      11>.Operating Humidity:5%~95%RH
      12>.Module Size:90*62*19mm
    I hope these parameters can help you and me in the further.
    Thanks
    Han Hoang

    #6366
    MikhailMikhail
    Moderator

    Could you send communication line log again? Resize the application window to show more information.

    What converter do you use to connect the module to a computer?

    #6367
    Avatarmanjey73
    Participant

    https://ibb.co/zGwRPtc

    Where did you get this template ?

    #6368
    Avatarhethongscada62
    Participant

    Dear manjey73,
    That template was created by me.
    Thanks a lot

    #6369
    Avatarhethongscada62
    Participant

    Dear Mikhail,
    What converter do you use to connect the module to a computer?
    RS485-RS232-USB converter. This converter connects to a computer. The relay board R421A08 was tested by Modbus Poll – MbPoll1 using this converter. Send commands from Mbpoll1, the relay works perfectly. You can see the screenshot:
    https://ibb.co/c67893j
    Now connecting a converter to computer using Communicatore to send commands. Configurations were sent to you. The relay can not work. Some screenshots were taken again:
    https://ibb.co/dKLFqHP
    https://ibb.co/FWLkvG6
    Thank you so much
    Han Hoang

    #6372
    Avatarmanjey73
    Participant

    Why didn’t you use my template ? It is checked since I used this relay Board

    can’t you see the difference between what ModbusPoll sends and yours ? ModbusPoll adds the calculated Checksum to the query. You do not add a binary command when you send it. The relay works with HoldingRegisters requests, you are trying to work with Coils

    • This reply was modified 6 months ago by Avatarmanjey73.
    #6374
    Avatarmanjey73
    Participant

    Once again I offer my template for this relay

    In the Communicator, disable the binding to the Server (Bounds), download my template and start the Communicator

    Online Modbus Parser

    Check Request Modbus RTU from ModbusPoll

    01 06 00 01 01 00 D9 9A

    and other

    • This reply was modified 6 months ago by Avatarmanjey73.
    #6376
    Avatarhethongscada62
    Participant

    Dear manjey73,
    Thank you so much. I was tried again to use your template. The result get better. The communication between communicator and relay board was set up. But the status of relay is not changed when i send the commands (standard, binary, string, hexdecimal). Some screenshot are bellowing:
    https://ibb.co/prXbJ5g
    https://ibb.co/d2H2G5M
    https://ibb.co/DwgNpQz
    https://ibb.co/Kxq8z0t
    https://ibb.co/JcDhnGH
    Where is wrong? I did not understand. Can you check it again?
    Thank you again
    Han Hoang

    #6377
    Avatarmanjey73
    Participant

    https://ibb.co/JcDhnGH – Here you send the string again

    https://ibb.co/DwgNpQz – Here in the first two lines you can see that the line went to ASCII-31 character code 1, 20-the code of the space character

    https://ibb.co/d2H2G5M – Here you are trying to send a command with the wrong CRC, try 01 06 00 01 02 00 D9 6A

    #6378
    Avatarmanjey73
    Participant

    Show part of the log Communication Line State

    Also try sending a Standard command, command number 1-8, value 256, 512 or 768

    • This reply was modified 6 months ago by Avatarmanjey73.
    #6382
    Avatarhethongscada62
    Participant

    Hi manjey. Because it did not work so I tried to test all types. Not at all
    Thinking now.
    Thank you again

    #6383
    Avatarmanjey73
    Participant

    So you were able to turn on and off the relay ?

    #6384
    Avatarhethongscada62
    Participant

    Hi manjey.
    Stil can not. Where is wrong i can not find.
    Very tried

    #6385
    Avatarhethongscada62
    Participant

    Dear manjey73,
    The problem was resolved. I can to control On-Off of relay now. The rapid Scada was great.
    Thank you very much.
    Han Hoang

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