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,

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.

[Andrew Neil]

It's not clear what "UART communication" you're talking about here?

Is it:

• between the two STM32 boards? 
• between the STM32 boards and something else? 
• Over the PLC link?

 

A diagram would provide a much clearer description...

 

PS:

Also, what boards are your STM32s on, etc?

 

How to write your question to maximize your chances to find a solution

[Midhul_Pk]

Let me clarify the issue more precisely.

I am using two identical setups, each consisting of:

• One STM32 board

• One X-NUCLEO-PLM01A1 (ST7580 PLC modem)

• On the transmitting side, UART communication between the STM32 and the ST7580 works initially, but data transmission is not continuous. After some packets, transmission stops.

• On the receiving side, the STM32 does not receive any data at all from its local ST7580 modem.

[TDK]

This is a duplicate of your previous question:

STM32C092 + X-NUCLEO-PLM01A1: UART TX works interm... - STMicroelectronics Community

 

Please don't repost the same question. You got engagement there, perhaps follow up to add more relevant details.

[Midhul_Pk]

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

[Andrew Neil]

---

@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.

How to write your question to maximize your chances to find a solution

Getting faster and better answers in the community

 

Note that ST have recently added an AI chatbot - might be worth giving it a try:

STM32 Sidekick: the AI-powered tool that accelerates your design journey

How to use STM32 Sidekick

In this situation the most common causes are incomplete ST7580 initialization and line-coupling issues rather than the MCU families themselves. TX_ON/RX_ON staying LOW usually means the modem never enters TX/RX state, which happens if mandatory ST7580 registers (mode, channel, modulation, AFE enable) or the reset-to-calibration timing sequence are missed; SPI/UART working alone isn’t enough. Also double-check the X-NUCLEO-PLM01A1 coupling network and impedance, as poor coupling will block PLC transmission entirely—much like how progress stalls without properly structured online learning programs, even when the tools themselves seem to work.