hi i am getting modbus poll pc application timeout error Could you please help me

[paxsipornax]

#include <ModbusSlave.h>
#include <SoftwareSerial.h>
SoftwareSerial RS485Serial(10, 11); // RX, TX

Modbus slave(RS485Serial, 1, 2);

int led = 12;

int dl_ro = 2;

void setup() {

pinMode(dl_ro, OUTPUT);
pinMode(led, OUTPUT);

slave.cbVector[CB_WRITE_COILS] = writeDigitalOut;

RS485Serial.begin(9600);
slave.begin(9600);

}

void loop() {
slave.poll();
}

uint8_t writeDigitalOut(uint8_t fc, uint16_t address, uint16_t length) {
Serial.print("FC=05: ");
Serial.println(fc);
Serial.println(address);
Serial.println(length);

if (address == led) {
digitalWrite(12, slave.readCoilFromBuffer(0));
}

return STATUS_OK;

}

[Erfan12699]

use arduino?