hello friends i have a teensy 4.1 with use of native ethernet over TCP IP protocol to communicate with DELTA HMI 100 series DOP-107WV . so when i try with teensy4.1 etherent to PC ethernet communication working . When i try DOP-107WV HMI ethernet to PC ethernet is working but when i DIrect connect Teensy4.1 Ethernet to HMI ethernet than communoication is not established . please help me if any solution .
above is code and below is the HMI setiing image
Code:
#include <NativeEthernet.h>
byte mac[] = { 0x04, 0xE9, 0xE5, 0x12, 0x34, 0x56 };
IPAddress ip(192, 168, 1, 20);
IPAddress subnet(255, 255, 255, 0);
EthernetServer server(502); // Modbus TCP standard port
bool coil0 = false; // LED coil
void setup() {
pinMode(13, OUTPUT);
digitalWrite(13, LOW);
Serial.begin(115200);
while (!Serial && millis() < 3000);
Ethernet.begin(mac, ip, subnet);
Serial.print("Teensy IP: ");
Serial.println(Ethernet.localIP());
server.begin();
Serial.println("Modbus TCP Server READY");
}
void loop() {
EthernetClient client = server.available();
if (!client) return;
uint8_t req[260];
uint8_t res[260];
while (client.connected()) {
if (!client.available()) continue;
int len = client.read(req, sizeof(req));
if (len < 8) continue;
uint16_t transId = (req[0] << 8) | req[1];
uint8_t unitId = req[6];
uint8_t fc = req[7];
// ---------------- FC05 : Write Single Coil ----------------
if (fc == 0x05) {
uint16_t coilAddr = (req[8] << 8) | req[9];
uint16_t value = (req[10] << 8) | req[11];
Serial.print("FC05 received, coil=");
Serial.print(coilAddr);
Serial.print(" value=");
Serial.println(value == 0xFF00 ? "ON" : "OFF");
if (coilAddr == 0) {
coil0 = (value == 0xFF00);
digitalWrite(LED_BUILTIN, coil0);
}
memcpy(res, req, 12);
client.write(res, 12);
}
// ---------------- FC03 : Read Holding Register ----------------
else if (fc == 0x03) {
uint16_t regAddr = (req[8] << 8) | req[9];
uint16_t qty = (req[10] << 8) | req[11];
uint16_t adc = analogRead(A0);
res[0] = req[0]; // Transaction ID
res[1] = req[1];
res[2] = 0x00; // Protocol ID
res[3] = 0x00;
res[4] = 0x00;
res[5] = 0x05 + qty * 2; // Length
res[6] = unitId;
res[7] = 0x03;
res[8] = qty * 2;
for (int i = 0; i < qty; i++) {
uint16_t val = (regAddr + i == 0) ? adc : 0;
res[9 + i * 2] = val >> 8;
res[10 + i * 2] = val & 0xFF;
}
client.write(res, 9 + qty * 2);
}
}
client.stop();
}
