Help Needed: RS485 Communication with Hexing Meter

Hi!

Thank you for the quick response. I was able to connect to the meter using GXDLMSDirector and Python. For anyone having issues with this manufacturer (which is quite notorious for the lack of support), these are the settings that worked for me:

Optical probe:

Interface: HDLCWithModeE

Authentication: High

Client Address: 1

Password: 00000000

ASCII: Disabled

Address Type: Default

Logical Server: 0

Physical Server: 1

Serial Port: YOUR PORT (Baud rate: 300, Data bits: 7, Parity: Even, Stop bits: 1, Flow control: None)

RS485:

Interface: HDLC

Authentication: High

Client Address: 1

Password: 00000000

ASCII: Disabled

Address Type: Default

Logical Server: 0

Physical Server: 1

Serial Port: YOUR PORT (Baud rate: 9600, Data bits: 8, Parity: None, Stop bits: 1, Flow control: None)

And here are the readings I obtained:

--------------------------------------------------
Siguiente desconexión en 13 lecturas.
--------------------------------------------------
Leyendo valor, lectura N° 28/500...
Tensión instantanea L1: 227.9 V
Corriente instantanea L1: 0.0 mA
Frecuencia de la red: 50.02 Hz
Factor de Potencia: 1.0
Energía Activa Total: 0.0 kWh
Potencia activa instantanea L1: 0 W
Tensión instantanea L2: 227.7 V
Tensión instantanea L3: 227.7 V
Corriente instantanea L2: 0.0 mA
Corriente instantanea L3: 0.0 mA

Now i have to convert my code to something i can program my ESP.

Again, thank you so much.

Hi,

I’m working with an ESP32 and I’m having some trouble with the code. Specifically, I’m trying to figure out where I can define the OBIS codes I want to read. Could I get some guidance on this?

Hi,

Sorry to bother again, but I'm not capable of stablish connection with the meter using ESP32 with HIGH authentication and the 00000000 password, in python i had no problem, using the password 0x00000000. If I use authentication NONE with no password and client 16 i can connect but not read anything.

Client.init(true, 1, 1,DLMS_AUTHENTICATION_HIGH, 0000000, DLMS_INTERFACE_TYPE_HDLC);

Hi,

Thank you for your help and patience. I tried several variations using quotes, like "00000000" and 0x00000000, but had no luck. Do you have any other suggestions? I am stuck with this.

Hi,

I double-checked, and both the Client and Server settings are the same.

In Python I have:

main.py -S COM3:9600:8None1 -i HDLC -c 1 -s 1 -a High -P 0x00000000

and it works.

In Arduino I’m using:

Client.init(true, 1, 1, DLMS_AUTHENTICATION_HIGH, "00000000", DLMS_INTERFACE_TYPE_HDLC);

and nothing.

However, if I use:

Client.init(true, 16, 1, DLMS_AUTHENTICATION_NONE, NULL, DLMS_INTERFACE_TYPE_HDLC);

I can connect to the meter. So I assume the issue is related to the password.

Since I’m using a MAX485 transceiver, I had to add custom read/write functions to handle the direction control pin (RS485_DIR). Otherwise, communication was impossible. Maybe this is also related to why it’s not working properly:

int rs485Write(const void* data, size_t len) {
// Cambiar a modo TX
digitalWrite(RS485_DIR, HIGH);
delay(1); // Pequeña pausa para estabilizar

// Enviar datos
int written = Serial.write((const uint8_t*)data, len);
Serial.flush(); // Esperar hasta que se envíen todos los datos

// Volver a modo RX
delay(1); // Pequeña pausa para asegurar transmisión completa
digitalWrite(RS485_DIR, LOW);

// Depuración
Serial1.print("TX: ");
for(int i=0; i<len; i++) {
Serial1.printf("%02X ", ((uint8_t*)data)[i]);
}
Serial1.println();

return written;
}

int rs485Read(uint8_t* buffer, size_t len, unsigned long timeout) {
size_t i = 0;
unsigned long start = millis();

while (i < len && (millis() - start) < timeout) {
if (Serial.available()) {
buffer[i++] = Serial.read();
start = millis(); // Resetear timeout con cada byte recibido
}
}

// Depuración
Serial1.print("RX: ");
for(int j=0; j<i; j++) {
Serial1.printf("%02X ", buffer[j]);
}
Serial1.println();

return i;
}

Hi,

Thank you so much for your response. Yesterday, late in the day, I finally managed to authenticate using basically the same method you updated in the repository. Your help has been incredible, and I now have a functional prototype running on an ESP32.

If at any point you or someone need a hand or some collaboration, feel free to reach out.

Best regards!