Showing results 1 to 2 of 2

Thread: Problem in reading 64Bit Modbus register of type 'Double' with MODRTU32

  1. #1
    karim Gast

    Ausrufezeichen Problem in reading 64Bit Modbus register of type 'Double' with MODRTU32

    We have a problem with the Modbus driver MODRTU32, our client has to perform a pre-FAT of the project tomorrow,

    This project is a DPM application (Diagnostic Performance and monitoring application); we have already succeeded with a previous project.

    But for this project they changed the flow-computer (Modbus slave device); the flow computer which is Flow boss model (Emerson) is using 64 bit for ‘DOUBLE’ registries

    I was not aware of it till now where I get the client’s test result;

    Those registries are located at registry: 7000 / 7004 / 7008 / 7012

    Could you advice us what to do to read those registries?

    I will really appreciate a quick answer as the client is at this moment waiting from my suggestion to close those unexpected issues before tomorrow.

    Thank you

    Karim

  2. #2

    Default Re: Problem in reading 64Bit Modbus register of type 'Double' with MODRTU32

    As you probably already have seen in the driver documentation, the Modbus RTU driver currently does not support LREAL or ULINT datatypes.


    * Do you have a specification sheet or a manual for these Emerson flow computer?
    * What exactly does this "DOUBLE" represent?
    * Is it a Double precision Float variable? (LREAL)


    The registry 7000 / 7004 / 7008 / 7012 seem to me be a little odd, at least if this should be the offset for the zenon variable.

    For the modbus protocol, a holding register is 16 bit long. This means, that Offset "7000" reads the first INT (16 bit), Offset "7001" reads the second INT (16 bit), Offset "7002" reads the third INT and Offset "7003" reads the fourth INT of a total of 64 bit.

    If the customer can read the data with INT variables with the offets above from the device, these INT variables somehow then need to be put together into a LREAL. (double float). straton should be able to help here.

Similar Threads

  1. variable type time didn't appear in zenon
    By johnny in forum Engineering Studio Logic & Logic Service (former zenon Logic Workbench & Runtime)
    Replies: 3
    Last Post: 16th January 2009, 12:11
  2. Replies: 2
    Last Post: 3rd April 2008, 12:24
  3. Processor type
    By sebastiank in forum zenon Service Engine Operator
    Replies: 0
    Last Post: 19th September 2007, 16:15
  4. more than one driver of same type
    By sebastiank in forum zenon Service Engine Operator
    Replies: 0
    Last Post: 18th September 2007, 07:36

Posting Rules

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •