Problems with function modbus_strerror(errno).

[Camilo Andrés]

Hello everyone. 

I'm using libmodbus with "Visual Studio 2013". I have a problem. When I use the "modbus_strerror (errno)" method to print the error message, I always get the message "No error", because the value of "errno" is not updated.

The library functions "LibModbus" are executed correctly; the downside is when there is an error (in connection or polling), the message I get is: "No error"

I've used in the following examples in C ++:

_______............._______________

modbus_t * channel;

...

this-> statusChannel = modbus_connect (this-> channel);

if (this-> statusChannel == -1)

{

msg.clear ();

msg = "Connection failed:" + (string) modbus_strerror (errno);

cout << std :: endl << msg;

modbus_free (this-> channel);

}

___________........................___________

uint8_t * tab_rp_bit = new uint8_t [numberAddresses];

int rc = modbus_read_bits (channel, StartAddress, numberAddresses, tab_rp_bit);

if (rc == -1)

{

msg.clear ();

msg = "Error reading" + to_string (numberAddresses) + "Coil Status from address" + to_string (StartAddress) + ":" + (string) modbus_strerror (errno);

cout << std :: endl << msg;

}

___________________.....................__________

I always use en my files:

#include <stdio.h>

#ifndef _MSC_VER

#include <unistd.h>

#endif

#include <string.h>

#include <stdlib.h>

#include <errno.h>