Hi!
I'm trying to communicate with my GoodWe inverter using the meter port, [this document ] (https://forum.iobroker.net/assets/uploads/files/1666333836822-goodwe_modbus_protocol_hybrid_et_eh_bh_bt__arm205-hv__v1.7-_-read-only_20200226-1.pdf), [this document] (https://downloads.vodnici.net/uploads/wpforo/attachments/483/4349-1GoodweModbusPROTOCOLHybrid-ENV1-3EMseries.pdf),
, an ESP32-WROOM-32S, the modbusmaster library and a XY-017 rs485 ttl converter. But, I can't get it to work. The only id not showing error "Invalid slave ID" is 3, so I assumed that is probably the id I'm looking for. But using id 3 gives me timeout issues.
the XY-017 RS485 side GND is connected to the GND of the inverter (tried it without gnd too, didn't make a difference)
RX -> RX
TX--> TX
The code looks like this;
#include <ModbusMaster.h>
ModbusMaster node;
int i;
int winningId = -1;
void setup() {
Serial.begin(9600);
Serial1.begin(9600, SERIAL_8N1, 16, 17);
// Serial1.setTimeout(2000);
node.begin(3, Serial1);
//node.begin(85, Serial1);
//node.begin(193, Serial1);
int i = 0;
}
void loop() {
// node.begin(i, Serial1);
uint8_t result;
uint16_t data[1];
result = node.readHoldingRegisters(36044, 1); //Meter protocol version
// result = node.readHoldingRegisters(0x050E, 1); // Battery SOC
// result = node.readHoldingRegisters(306, 38); // Inverter request
if (result == node.ku8MBSuccess) {
data[0] = node.getResponseBuffer(0);
Serial.println("Protocol version: ");
Serial.println(data[0]);
winningId = i;
} else {
Serial.println("Error code: ");
Serial.println(result);
switch(result) {
case node.ku8MBIllegalFunction:
Serial.println("Illegal function");
break;
case node.ku8MBIllegalDataAddress:
Serial.println("Illegal data address");
break;
case node.ku8MBIllegalDataValue:
Serial.println("Illegal data value");
break;
case node.ku8MBSlaveDeviceFailure:
Serial.println("Slave device failure");
break;
case node.ku8MBInvalidSlaveID:
Serial.println("Invalid slave ID");
break;
case node.ku8MBInvalidFunction:
Serial.println("Invalid function");
break;
case node.ku8MBResponseTimedOut:
Serial.println("Response timed out");
break;
case node.ku8MBInvalidCRC:
Serial.println("Invalid CRC");
break;
default:
Serial.println("Unknown error");
break;
}
i += 1;
Serial.print("new i: ");
Serial.println(i);
Serial.print("winning id: ");
Serial.println(winningId);
}
// delay(2000);
delay(1);
}
I logged the master request from the inverter via the meter port using the following code;
#include <SoftwareSerial.h>
SoftwareSerial rs485(16,17);
void setup() {
Serial.begin(9600);
rs485.begin(9600);
}
void loop() {
while ( rs485.available() > 0 ) {
Serial.print(rs485.read());
Serial.print(" ");
}
}
I found that the inverter is sending the following request to the smart meter: 3 3 1 50 0 38 101 193 which would indicate that it is trying to reach the smart meter with slave id 3, using function code 03H at address 306 expecting 38 bytes right? I tried sending this exact request.
The goal is to simulate the GM1000D smart meter so I can be in control of the data being sent to the inverter. Any help is appreciated!