How to communicate between NodeMCU and PC via MAX485?

hello ,am new to this forum.so any mistake happen please don't mind.
my question is how to make communicate with nodemcu with pc via max485.i just tried a simple program but that's not worked.any one please help me.
one more thing for sending data to nodemcu am using serail lab in my pc.
here is my code

#include <ModbusMaster.h>
#include <SoftwareSerial.h>
ModbusMaster node;

void setup()
{
pinMode(7, INPUT_PULLUP);

Serial.begin(9600);
delay(100);
node.begin(1,Serial);
delay(100);
}
void loop()
{

node.writeSingleRegister(4,digitalRead(7));
Serial.print("[4] ");
Serial.print(digitalRead(7));
delay(20);
Serial.print(" ");
node.readHoldingRegisters(5,1);
Serial.print("[5] ");
Serial.println(node.getResponseBuffer(0));
delay(20);
node.clearResponseBuffer();
}

if anybody have knowledge about this please help me.thanku