.. _get_input_register_bit:

get_input_register_bit
------------------------------------------
This function reads a **single bit** from the controller **input register**  
using the specified **register address**.  
It is typically used for PLC I/O register monitoring in Ethernet-based environments.

**Definition** |br|
``DRFLEx.h`` within class `CDRFLEx`, public section

.. code-block:: cpp

   bool get_input_register_bit(unsigned short address, int& out_val, int timeout_ms = 300) {
       return _get_input_register_bit(_rbtCtrl, address, &out_val, timeout_ms);
   };

**Parameter**

.. list-table::
   :widths: 20 20 20 55
   :header-rows: 1

   * - **Parameter Name**
     - **Data Type**
     - **Default Value**
     - **Description**
   * - address
     - unsigned short
     - -
     - **Input register address** (bit index, 0~63)
   * - out_val
     - int&
     - -
     - **Input bit value** to read |br|
       `0` : OFF |br|
       `1` : ON
   * - timeout_ms
     - int
     - 300
     - Timeout in milliseconds

**Return**

.. list-table::
   :widths: 25 75
   :header-rows: 1

   * - **Value**
     - **Description**
   * - 0
     - Error: failed to read input register bit
   * - 1
     - Success: input register bit read

**Example**

.. code-block:: cpp

   #include "DRFLEx.h"
   #include <iostream>

   using namespace DRAFramework;

   int main() {
       CDRFLEx robot;

       const char* ip = "192.168.137.120";
       if (!robot.open_connection(ip)) {
           std::cout << "Failed to connect: " << ip << std::endl;
           return 1;
       }

       // Read bit (timeout 300 ms)
       // Initialize to -1 to indicate “not read yet” if the call fails.
       int out_bit = -1;
       robot.get_input_register_bit(0, out_bit, 300);
       std::cout << "addr=0, out_bit=" << out_bit << std::endl;

       robot.close_connection();
       return 0;
   }

This example reads the input register bit at **address 0 (Bit_Input_Register[0])**.