ArduinoModbus : Modbus Client class
Perform a "Read Input Registers" operation for a single input register.
long inputRegisterRead(int address);
long inputRegisterRead(int id, int address);
id (slave) - id of target, defaults to 0x00 if not specified
Address - address to use for operation
input register value on success, -1 on failure.
ModbusClient Class
