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EVM430F6779 electric meter interface to serial terminal

Vijay Anand22
Prodigy 80 points

I want to interface EVM430F6779 electric meter to serial terminal.

I have already interfaced with the GUI using rs232 to my computer and i am  getting the desired results

I then did some research on DL/T645 and i am able to communicate with meter for getting phase1, phase2 and phase3 readings through serial terminal.

STEP1: I open GUI and wait for the signal to turn green

STEP2: I colse GUI and open serial terminal, configure COM and baudrate and then i send the code for phase1,phase2 and phase3 readings

The problem i am facing is i am not able to communicate directly by opening the serial terminal. First i have to open GUI and once the signal is green i close GUI, open serial terminal and then communicate for meter readings. 

If i bypass STEP1 and directly go to STEP2 i dont get any response from the meter. I guess there is some password set in the meter for enabling the communication and when i open GUI the password is sent by GUI and communication is triggered.

Do we really have any password? if yes please let me know the initial command that should be given to trigger communication.

If there is no password then how should i bypass step1?

My goal is to open serial terminal and start communication with the meter without any dependency of GUI.

Please solve my above problems. Thanks in advance.

  • 0
    TI__Guru**** 208927 points
    Here is the related thread: e2e.ti.com/.../545698

    Try looking in the log file (cal-log.txt) where you should see reports of the messages being sent to and from the meter. I believe there is some form of calibration or initialization command that must be sent before communication can commence. A logic analyzer would also be helpful in this case.

    Regards,
    Ryan
  • 0 in reply to Ryan Brown1
    Prodigy 80 points

    Thank You for your reply Ryan

    I went through the log file and i didnt get any hex code that is in DL/T -645 protocol

    I read the code and i got to know that the calibration password is 0x1234 0x5678 0x9abc and 0xdef0.

    I tried many format but i am unable to crack the initialization command.

    I guess i am doing some mistake in byte format formation

    Below mentioned are the details regarding my byte formation 

    Try: Below mentioned code are in Hex format. 

    68 99 99 99 99 99 99 68 23 0A 60 00 12 34 56 78 9A BC DE F0 EB 16

    Response: I didnt get any response, i doubted my checksum part and instead of EB i tried 05 23, I added all the hex code between 60 and EB and got 05 23, then i replaced EB with 05 23. Still i didnt get any response.

    From the code its pretty clear that my byte positions are correct but i doubt my checksum part. 

    Can you please aid me with this issue. Please correct my byte array if i am missing some thing.

    If you want more details or more explanation please feel free to ask.

    Thank You

  • 0 in reply to Vijay Anand22
    TI__Guru**** 208927 points

    Found a related thread confirming our assumptions: e2e.ti.com/.../1865553

    The issue may be related to the order in which the bytes from the packet are sent/received, please view the following threads and see if their suggestions help alleviate your issue:

    e2e.ti.com/.../468624
    e2e.ti.com/.../520026

    I notice that you are missing the four 0xFE bytes that should start the data packet.  The checksum involves summing all code starting at the first 0x68 and ending with the last byte of the message followed by ANDing that value with 0xFF.

    Regards,
    Ryan

  • 0 in reply to Ryan Brown1
    Prodigy 80 points

    Hi Ryan

    Thanks a lot.  I got the output.

    Thanks a lot for your reply and help.

    Cheers!

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