[Modbus]
The Modbus86 Master enables the 86Duino to emulate a Modbus Master and send packets to the Slave node on the channel.
Example
Example of Modbus Master with RS485 enabled and using Modbus RTU as the communication method.
#include <Modbus86.h>
ModbusMaster bus;
ModbusMasterNode node1;
ModbusMasterNode node2;
int led = 0;
uint32_t value = 0;
void setup()
{
Serial485.begin(115200);
/* Modbus RTU Mode via RS485. */
bus.begin(MODBUS_RTU, Serial485);
/* Slave node 1 with ID 11. */
node1.attach(11, bus);
/* Slave node 2 with ID 12. */
node2.attach(12, bus);
}
void loop()
{
uint16_t reg[2];
/* Write 1 coil to address 0 of the slave with ID 11. */
node1.writeSingleCoil(0, led);
/* Write 2 word to holding registers address 16 of
the slave with ID 11. */
reg[0] = value & 0xFFFF;
reg[1] = (value >> 16) & 0xFFFF;
node1.setTransmitBuffer(0, reg[0]);
node1.setTransmitBuffer(1, reg[1]);
node1.writeMultipleRegisters(16, 2);
/* Read 2 word from holding registers address 16 of
the slave with ID 11. */
node1.readHoldingRegisters(16, 2);
Serial.print("From Node 1 Holding Register: ");
value = node1.getResponseBuffer(0)
| (node1.getResponseBuffer(1) << 16);
Serial.println(value);
/* Read 1 word from input registers address 2 of
the slave with ID 11. */
node1.readInputRegisters(2, 1);
Serial.print(" Input Register: ");
Serial.print(node1.getResponseBuffer(0));
Serial.println();
/* Write 1 coil to address 0 of the slave with ID 12. */
node2.writeSingleCoil(0, led);
/* Write 2 word to holding registers address 16 of
the slave with ID 12. */
reg[0] = value & 0xFFFF;
reg[1] = (value >> 16) & 0xFFFF;
node2.setTransmitBuffer(0, reg[0]);
node2.setTransmitBuffer(1, reg[1]);
node2.writeMultipleRegisters(16, 2);
/* Read 2 word from holding registers address 16
of the slave with ID 12. */
node2.readHoldingRegisters(16, 2);
Serial.print("From Node 2 Holding Register: ");
value = node2.getResponseBuffer(0)
| (node2.getResponseBuffer(1) << 16);
Serial.println(value);
/* Read 1 word from input registers address 2 of
the slave with ID 12. */
node2.readInputRegisters(2, 1);
Serial.print(" Input Register: ");
Serial.print(node2.getResponseBuffer(0));
Serial.println();
led = !led;
value++;
delay(1000);
}Example of a Modbus Master using Ethernet and Modbus TCP as the communication method.
#include <Ethernet.h>
#include <Modbus86.h>
ModbusMaster bus;
ModbusMasterNode node;
byte mac[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
IPAddress localIp(192,168,1,101);
IPAddress serverIp(192,168,1,102);
int led = 0;
uint32_t value = 0;
void setup()
{
Ethernet.begin(mac, localIp);
/* Modbus TCP Mode via Ethernet. */
bus.begin(MODBUS_TCP, serverIp);
/* Slave node initialize. */
node.attach(11, bus);
}
void loop()
{
uint16_t reg[2];
/* Write 1 coil to address 0 of the slave with ID 11. */
node.writeSingleCoil(0, led);
/* Write 2 word to holding registers address 16 of
the slave with ID 11. */
reg[0] = value & 0xFFFF;
reg[1] = (value >> 16) & 0xFFFF;
node.setTransmitBuffer(0, reg[0]);
node.setTransmitBuffer(1, reg[1]);
node.writeMultipleRegisters(16, 2);
/* Read 2 word from holding registers address 16 of
the slave with ID 11. */
node.readHoldingRegisters(16, 2);
Serial.print("From Node 1 Holding Register: ");
value = node.getResponseBuffer(0)
| (node.getResponseBuffer(1) << 16);
Serial.println(value);
/* Read 1 word from input registers address 2 of
the slave with ID 11. */
node.readInputRegisters(2, 1);
Serial.print(" Input Register: ");
Serial.print(node.getResponseBuffer(0));
Serial.println();
led = !led;
value++;
delay(1000);
}Libraries Reference Home
The text of the 86Duino reference is a modification of the Arduino reference and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.



