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TRS3122E: RS232 transfer "00"

Part Number: TRS3122E

When the RS232 is powered on, why  the output transfers the character of "00"?

  • I'm sorry, the transfer data is "0x00" when the RS232 module powered up.

  • Hi,

    When the TRS3122E is powered with an idle voltage at the inputs, it will drive a constant voltage on the TX lines. Are you attempting to send data using the device and receiving nothing on a receiving device?

    Regards,

    Eric

  • Hi, Eric,

           You may misunderstanding my description.

           When the RS2322 module powered, the receiving device  automaticly received the string "0x00" but this string "0x00" is not actively triggered sending by the RS232.

          After powered up, when actively send some data, the receiveing device can normally these transfer data.

    Thanks,

  • Hi,

    Apologies, the RS232 standard only specifies a Physical layer. Since data interpretation can vary based on implementation, knowing only the data being received by a controller makes it difficult to know how the transceiver is behaving. Would you be able to specify what communication format is being used? 8-N-1 is one that is common for RS232.

    When the device is disabled (/FORCEOFF = L), the ROUT pin is high impedance. Once the device is enabled, it will output logic H or L depending on the state of the bus. If the bus is open, it will output a constant logic HIGH. It is also possible that a line held idle at >-3v is interpreted as a string of 0s. Could this be what you are interpreting at a data string of 0x00?

    The /INVALID pin will also output a logic LOW when it detects both RIN1 and RIN2 are open. It will then go HIGH when it detects a valid input condition on either RIN pin. Are you using this pin to trigger the start of a data frame?

    Regards,
    Eric

  • Hi Eric,

     Got you,thanks for your support.

    B&R