iqrok / modbus.helper

Modbus helper. Reading and writing via modbus-serial package

modbus-serial Helper

Helper for modbus-serial package in async/await.

USAGE

const modbusHelper = require('@iqrok/modbus.helper');
const modbus =new modbusHelper({
		ip: '127.0.0.1',
		port: 502,
		id: 1,
		byteOrder: [1,0,3,2],
		decimalDigits: null,
		debug: true,
		timeout: 1000,
    });

new modbusHelper ({ip, port, baud, byteOrder, decimalDigits, nullable, timeout, debug})

Parameters:

Name	Type	Attributes	Default	Description
ip	string			IP destination for modbus TCP
port	number|string			Port number for modbus TCP or path to serial port for modbus RTU
baud	number			Baud Rate for modbus RTU
byteOrder	Array.<number>	<optional>	[1,0,3,2]	byte order of modbus register
decimalDigits	number	<optional> <nullable>		number of decimals for floating point
timeout	number	<optional>	100	timeout in ms
debug	boolean	<optional>	false	Print debug message

byteLength (type) → {number}

Size of data type in bytes

Parameters:

Name	Type	Description
type	"UINT16" | "INT16" | "UINT32" | "INT32" | "FLOAT" | "FLOAT32" | "DOUBLE" | "FLOAT64"	number data type

Returns:

• data type size in bytes

numToWords (number, type) → {Array.\<number\>}

Convert number into array of unsigned integer 16-bits numbers

Parameters:

Name	Type	Description
number	number	number to be converted
type	"UINT16" | "INT16" | "UINT32" | "INT32" | "FLOAT" | "FLOAT32" | "DOUBLE" | "FLOAT64"	number data type

Returns:

• array of uint16 numbers

readCoils (addr, len) → {Promise.<Array.<Boolean>>|Promise.<Boolean>}

Read Coils (FC=1)

Parameters:

Name	Type	Attributes	Default	Description
addr	number			address to read from
len	number	<optional>	1	number of addresses to read

Returns:

• resolve false if reading is failed, otherwise resolve array of coils status

readDiscreteInputs (addr, len) → {Promise.\<Array.\<Boolean\>\>|Promise.<Boolean>}

Read Discrete Inputs (FC=2)

Parameters:

Name	Type	Attributes	Default	Description
addr	number			address to read from
len	number	<optional>	1	number of addresses to read

Returns:

• resolve false if reading is failed, otherwise resolve array of discrete inputs status

readHoldingRegisters (addr, len) → {Promise.<Buffer>|Promise.<Boolean>}

Read Holding Register (FC=3)

Parameters:

Name	Type	Attributes	Default	Description
addr	number			address to read from
len	number	<optional>	1	number of addresses to read

Returns:

• resolve false if reading is failed, otherwise resolve read Buffer

readInputRegisters (addr, len) → {Promise.<Buffer>|Promise.<Boolean>}

Read Input Register (FC=4)

Parameters:

Name	Type	Attributes	Default	Description
addr	number			address to read from
len	number	<optional>	1	number of addresses to read

Returns:

• resolve false if reading is failed, otherwise resolve read Buffer

wordsLength (type) → {number}

Size of data type in words

Parameters:

Name	Type	Description
type	"UINT16" | "INT16" | "UINT32" | "INT32" | "FLOAT" | "FLOAT32" | "DOUBLE" | "FLOAT64"	number data type

Returns:

• data type size in words

wordsToNum (words, type, digits, nullable) → {number}

Convert Words received from modbus to number

Parameters:

Name	Type	Attributes	Description
words	Buffer	Array.<uint16>
type	"UINT16" | "INT16" | "UINT32" | "INT32" | "FLOAT" | "FLOAT32" | "DOUBLE" | "FLOAT64"		number data type
digits	number	<optional> <nullable>	number of decimal digits for float, will be default to set decimalDigits in config if left undefined

Returns:

• converted number

writeCoil (addr, values) → {Promise.<Object>|Promise.<boolean>}

Write Single Coil (modified FC=15)

Parameters:

Name	Type	Description
addr	number	address to write
values	boolean	array of values to write

Returns:

• resolve false if reading is failed, otherwise resolve address and length of written registers

writeCoils (addr, values) → {Promise.<Object>|Promise.<boolean>}

Write multiple Coils (FC=15)

Parameters:

Name	Type	Description
addr	number	address to write
values	Array.<boolean>	array of values to write

Returns:

• resolve false if reading is failed, otherwise resolve address and length of written registers

writeRegister (addr, value) → {Promise.<Object>|Promise.<Boolean>}

Write single Holding Register (FC=6)

Parameters:

Name	Type	Description
addr	number	address to write
value	number	value to write

Returns:

• resolve false if reading is failed, otherwise resolve address and length of written registers

writeRegisters (addr, values) → {Promise.<Object>|Promise.<Boolean>}

Write multiple Holding Registers (FC=16)

Parameters:

Name	Type	Description
addr	number	address to write
values	Array.<number>	array of valuess to write

Returns:

• resolve false if reading is failed, otherwise resolve address and length of written registers