Type casting operation - arduino

Question

I am using NodeMCU & Energy meter. Energy meter is Modbus RTU device which display parameter in 32 bit. With below piece of code I could able to read the data from slave but need method to type cast from into 32 bit floating & display
When I change the value to unsigned decimal in ModScan software the values showing properly. But I need to display value in 32 bit floating point.
#include <ModbusMaster232.h>
#include <SoftwareSerial.h>
float data[100];
ModbusMaster232 node(1);
// Define one address for reading
#define address 1
// Define the number of bits to read
#define bitQty 70
void setup()
{
Serial.begin(9600);
// Initialize Modbus communication baud rate
node.begin(9600);
}
void loop()
{
int result = node.readHoldingRegisters(address, bitQty);
data[0] = (float)node.getResponseBuffer(0);
data[1] = (float)node.getResponseBuffer(1);
data[2] = (float)node.getResponseBuffer(2);
data[3] = (float)node.getResponseBuffer(3);
data[4] = (float)node.getResponseBuffer(4);
data[5] = (float)node.getResponseBuffer(5);
for (int i = 0; i < 100; i++)
{
//data[i] = node.getResponseBuffer(i);
Serial.println(data[i]);
}
Serial.println("............");
}
I would like to display the reading as shown in Modbus with type casting.
Actual Modbus device output from salve:
Arduino output while read data from energy meter:

Answer 1

You are casting a 16-bit word into a float. Check the slave documentation to find how they map a 32-bit floating point into two Modbus registers. Basically you need to know where the least significant word is (first or second register), load them into memory (shift if necessary) and cast to float.

Answer 2

I am looking and trying to solve exact same problem (with same results). This may help:
function read() {
client.readHoldingRegisters(0000, 12)
.then(function(d) {
var floatA = d.buffer.readFloatBE(0);
console.log("Total kWh: ", floatA); })
.catch(function(e) {
console.log(e.message); })
.then(close);
}
This is NodeJS and javascript version, which works and Arduino does not. Complete example can be found here and it works on Raspberry Pi https://github.com/yaacov/node-modbus-serial/blob/master/examples/buffer.js