X-NUCLEO-PLM01A1: ST7580 TX/RX not continuous, no data reception, TX_ON/RX_ON LEDs not blinking

[Midhul_Pk]

Hello,

I am working with two X-NUCLEO-PLM01A1 PLC expansion boards, each connected to a different STM32 MCU board.

Hardware setup:

• Transmitter MCU: STM32C092CBT6

• Receiver MCU: STM32G070CBT6

• PLC modem: ST7580 on both X-NUCLEO-PLM01A1 boards

• Both boards are connected over the same power line

Problem description:

• I am trying both DL mode and physical data transmission.

• Data transmission is not continuous.

• The receiver board does not receive correct data (data is corrupted or not received).

• The TX_ON and RX_ON LEDs on both X-NUCLEO-PLM01A1 boards remain LOW and do not blink during transmission or reception.

• The ST7580 IC replies on SPI/UART, but no proper PLC data transfer occurs.

Additional observation:

• I also tried using the ST-provided API / middleware available on the ST website, but the transmission gets stuck with a transmission error and does not complete successfully.

Observations:

• SPI/UART communication between MCU and ST7580 is working.

• T_REQ behavior has been checked.

• Despite transmission attempts, TX_ON and RX_ON LEDs never indicate activity.

Questions:

1. What are the possible reasons for TX_ON and RX_ON LEDs staying LOW?

2. Are there any mandatory ST7580 configuration registers that must be set for continuous transmission?

3. Are there known issues or differences when using different MCU families (STM32C0 vs STM32G0) with X-NUCLEO-PLM01A1?

4. Is there any recommended initialization or timing sequence required before starting DL or physical data transmission?

5. Could this be related to line coupling, impedance, or hardware configuration on the X-NUCLEO-PLM01A1?

6. Are there any known limitations or required adaptations when using the ST7580 API on non-reference MCU boards?

Any guidance, reference designs, or example configurations would be very helpful.

Thank you in advance.

[Midhul_Pk]

Merged threads for the same subject.

Hello st Community,

I would like to ask for your support regarding an issue I am facing with the ST7580 power line communication IC.

I am using two STM32 boards:

STM32C092CBT6 (Board 1)

STM32G072CBT6 (Board 2)

Both boards are configured with the same ST7580 configuration settings. All configuration commands are acknowledged correctly, and I receive both ACK and Confirm messages for each configuration step.

For data communication:

I am using the DL method to send data

I am transmitting 10 bytes of data

The transmitter receives the ACK and Confirm successfully

However, on the reception board, the received data is not appearing on the RX_IN power line interface. No data is observed even though:

Both boards share the same power line and common ground

Power line and hardware connections are verified and appear correct

Configuration ACK and Confirm responses are received correctly

RX_ON / TX_ON behavior:

Both RX_ON and TX_ON signals remain at logic low

Even when these pins are pulled up by the MCU, they still remain low

As a result, the corresponding RX/TX status LEDs never turn ON

Additional observation (Sniffer indication):

Occasionally, the reception board receives sniffer indication packets

However, this occurs only intermittently

In the transmit case, since ACK and Confirm are received consistently, I am unsure why the reception board sometimes reports sniffer indications instead of normal RX data

I would like to understand under what conditions the ST7580 generates sniffer indication packets and why this might happen when DL transmission appears successful

Based on this, my concerns are:

Why the reception board is not forwarding or outputting the received data on RX_IN, despite successful configuration and DL transmission acknowledgment

Whether an additional command or request is required for the reception board to output received data

Whether the constant low state of RX_ON and TX_ON indicates a configuration, pin-mux, or hardware-related issue

Why sniffer indication packets are received intermittently on the RX board even though the TX board receives ACK and Confirm messages

Could you please advise if there are any required initialization steps, operating modes, or known conditions that could cause this behavior?

Any guidance or recommendations would be greatly appreciated.

Thank you for your time and support.

Best regards,
Midhul Pk

[Andrew Neil]

This looks like a duplicate of your previous thread:

https://community.st.com/t5/stm32-mcus-products/x-nucleo-plm01a1-st7580-tx-rx-not-continuous-no-data-reception/td-p/864874

where you've already been asked not to duplicate threads.

[mƎALLEm]

Three threads were created for almost the same subject.:

https://community.st.com/t5/others-stm32-mcus-related/x-nucleo-plm01a1-st7580-tx-rx-not-continuous-no-data-reception/td-p/864550

https://community.st.com/t5/others-stm32-mcus-related/x-nucleo-plm01a1-st7580-tx-rx-not-continuous-no-data-reception/td-p/864874

https://community.st.com/t5/others-stm32-mcus-related/st7580-power-line-communication-issue/td-p/865629

Could you please keep the discussion in the same thread for the same question?

[Andrew Neil]

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@Midhul_Pk wrote:

 I couldn’t get proper replies. That’s why I posted it again.

---

You haven't answered questions, and haven't provided details requested:

1. A diagram of your setup.
2. Full part numbers of the stuff you are using.
3. Details of what investigation/debugging you have done.
4. Have you tried known-good examples

Just repeating the same question without providing requested information isn't going to get better answers.

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