Modbus communication error

Forum Home Forums Communicating with Devices Modbus Modbus communication error

This topic contains 3 replies, has 2 voices, and was last updated by Mikhail Mikhail 4 months, 1 week ago.

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #5779
    Avatar
    dineshkumargowd
    Participant

    Dear Mikhail,

    I am trying to communicate with Modbus Data acquisition module whose address is 1, baud rate is 9600, parity = No, stop bit = 1. I have assigned holding registers in modbus template. When i am starting the communicator i am receiving the communication error. Kindly help in this regard.

    Initially i was using another version of Rapidscada, i was able to read those registers with the old version. But i am unable to read them from the new version of 5.7.

    Following is the communication log for your reference

    2019-08-01 18:29:28 Communication session with the Device 61 “E830_DAQ”, type: ScadaCommCommon, address: 1
    Request element group
    Send (8): 01 03 00 01 00 08 15 CC
    Receive (0/5):
    Communication error!
    Request element group
    Send (8): 01 03 00 01 00 08 15 CC
    Receive (0/5):
    Communication error!
    Request element group
    Send (8): 01 03 00 01 00 08 15 CC
    Receive (0/5):
    Communication error!

    #5780
    Mikhail
    Mikhail
    Moderator

    Hello,

    Working with Modbus devices was not changed in Rapid SCADA 5.7. From the log we can see that the device doesn’t respond. You should check serial connection.

    #5782
    Avatar
    dineshkumargowd
    Participant

    Dear Mikhail,

    It worked Now.

    Device was not responded, since i have assigned the Holding registers(one register – 02 bytes) as Unsigned(16) initially. Later on changing them all to Signed(16), it worked well.

    Serial connection was good, since it worked with other Modbus Master software.

    Thanks for your immediate response.

    #5785
    Mikhail
    Mikhail
    Moderator

    Thank you for the info.

Viewing 4 posts - 1 through 4 (of 4 total)

You must be logged in to reply to this topic.