CONTROLLINO Library

When synchronizing Modbus data with physical Controllino pins, the pin assignments depend on the hardware model being used. Ensure both Server and Client use the same definitions to maintain synchronization.

Controllino MAXI

• Digital Coils/Inputs: Uses NUMBER_INPUTS_COILS (5).
• Analog Registers: Uses NUMBER_IN_HOLD_REGISTERS (5).
• Analog Start Pin: CONTROLLINO_A5.

Controllino MEGA

• Digital Coils/Inputs: Uses NUMBER_INPUTS_COILS (11).
• Analog Registers: Uses NUMBER_IN_HOLD_REGISTERS (5).
• Analog Start Pin: CONTROLLINO_A11.

Pin Initialization Pattern

To map Modbus data to pins, iterate through the configured counts and use pinMode or analogWrite to initialize the hardware state.

// Example for MAXI digital pin setup
for (int i = 0; i < NUMBER_INPUTS_COILS; i++) {
  pinMode(CONTROLLINO_A0 + i, INPUT);
  pinMode(CONTROLLINO_R0 + i, OUTPUT);
  digitalWrite(CONTROLLINO_R0 + i, LOW);
}

// Example for Analog pin setup
for (int i = 0; i < NUMBER_IN_HOLD_REGISTERS; i++) {
  pinMode(FIRST_ANALOG_INPUT_PIN + i, INPUT);
  pinMode(CONTROLLINO_D0 + i, OUTPUT);
  analogWrite(CONTROLLINO_D0 + i, 0);
}

In a Modbus TCP setup, two Controllino devices act as a Server and a Client to synchronize physical I/O points over an Ethernet network.

The Server (Data Holder)

• Manages physical inputs and outputs.
• Listens on a specific IP address and port (typically 502) for incoming requests.
• Provides the current state of its inputs and executes commands to change its outputs.

The Client (Controller)

• Connects to the Server's IP address.
• Retrieves the current state of the Server's inputs.
• Sends commands to the Server to update the Server's outputs based on its own control logic.

Synchronization Logic

• Digital I/O: The Client reads Discrete Inputs from the Server (to monitor sensors/switches) and writes to the Server's Coils (to control relays/LEDs).
• Analog I/O: The Client reads Input Registers from the Server (to monitor sensors like temperature) and writes to the Server's Holding Registers (to control analog outputs like motor speeds).

To implement a Modbus RTU Master using a Controllino Mega, you must use the ArduinoModbus and ArduinoRS485 libraries. The master device acts as a client that reads from and writes to a slave device's registers and coils.

Key synchronization logic in this pattern:

1. Digital Synchronization: Read discrete inputs from the slave and write them to the master's digital outputs. Simultaneously, read the master's digital inputs and write them to the slave's coils.
2. Analog Synchronization: Read input registers from the slave and write them to the master's analog outputs. Simultaneously, read the master's analog inputs and write them to the slave's holding registers.

Required libraries:

• Controllino.h
• ArduinoRS485.h
• ArduinoModbus.h

#include <Controllino.h>  
#include <ArduinoRS485.h>  
#include <ArduinoModbus.h>  

#define CONTROLLINO_MEGA_SLAVE  1  
#define NUMBER_INPUTS_COILS  11    
#define NUMBER_IN_HOLD_REGISTERS 5 

void setup() {
  Serial.begin(9600);
  // Initialize Modbus RTU Client
  if (!ModbusRTUClient.begin(9600)) {
    while (1); // Halt on error
  }
}

void loop() {
  // Example: Reading discrete inputs and writing coils
  for (int i = 0; i < NUMBER_INPUTS_COILS; i++) {
    int val = ModbusRTUClient.discreteInputRead(CONTROLLINO_MEGA_SLAVE, i);
    if (val >= 0) {
      digitalWrite(CONTROLLINO_R0 + i, val);
    }
    ModbusRTUClient.coilWrite(CONTROLLINO_MEGA_SLAVE, i, digitalRead(CONTROLLINO_A0 + i));
  }
}

To install the bootloader on a CONTROLLINO MAXI, use an ISP programmer (such as an Atmel-ICE) connected to the X1 pin header. Follow these steps:

1. Hardware Connection: Connect the ISP programmer to the CONTROLLINO X1 header using the following pin mapping:
   • TCK $\rightarrow$ SCK
   • GND $\rightarrow$ GND
   • TDO $\rightarrow$ MISO
   • VTref $\rightarrow$ VCC (5V!)
   • nSRST $\rightarrow$ Reset
   • TDI $\rightarrow$ MOSI
2. PC Connection: Connect the ISP programmer to your computer.
3. Power: Provide power to the CONTROLLINO via USB or an external power supply.
4. Software Setup: Open Atmel Studio and navigate to Tools $\rightarrow$ Device programming.
5. Device Configuration: Set the Device to ATmega2560 and the Interface to ISP. Verify the signature and voltage.
6. Flash Bootloader: Navigate to Tools $\rightarrow$ Device programming $\rightarrow$ Memories. In the Flash section, select the path to the Bootloader_CONTROLLINO_MAXI.hex file (downloaded from GitHub) and click Program.

Note: The current bootloader version (1.0) is a modified ATmega2560 bootloader that removes the requirement to use LEDONBOARD while uploading new sketches.

### Pin Mapping for X1 Header
- TCK -> SCK
- GND -> GND
- TDO -> MISO
- VTref -> VCC (5V!)
- nSRST -> Reset
- TDI -> MOSI