Modbus TCP Connector | X4Documentation

This adapter connects to devices via the Modbus TCP protocol.

Properties

Operation

Defines the operation executed by the adapter

Possible values:

Read: Reads data from the Modbus server
Write: Writes data to the Modbus server

Parameters

ip

Server IP

port

Server port

Possible values:

any port number
502 (default)

Status values

`1`	The operation was executed successfully
`-1`	Any error occurred during the operation's execution

Input

The adapter expects a specific XML structure for the different operations:

Operation Read:

Sample input for operation READ

XML

<?xml version="1.0" encoding="UTF-8"?>
<Request>
	<InputRegisters count="2" ref="0"/>
	<InputRegisters count="1" ref="3"/>
	<HoldingRegisters count="2" ref="0"/>
	<HoldingRegisters count="1" ref="3"/>
	<Discretes count="2" ref="0"/>
	<Discretes count="1" ref="3"/>
	<Coils count="2" ref="0"/>
	<Coils count="1" ref="3"/>
</Request>

Operation Write:

Sample input for operation WRITE

XML

<?xml version="1.0" encoding="UTF-8"?>
<Request>
	<HoldingRegister ref="11">14</HoldingRegister>
	<Coil ref="20">true</Coil>
	<Coil ref="000E1">TRUE</Coil>
</Request>

Output

The adapter outputs different structures depending on the executed operation:

Operation Read:

Sample output for operation READ

XML

<?xml version="1.0" encoding="UTF-8"?>
<Request>
	<InputRegisters count="2" ref="0">
		<Result>
			<InputRegister ref="0">0</InputRegister>
			<InputRegister ref="1">0</InputRegister>
		</Result>
	</InputRegisters>
	<InputRegisters count="1" ref="3">
		<Result>
			<InputRegister ref="0">0</InputRegister>
		</Result>
	</InputRegisters>
	<HoldingRegisters count="2" ref="0">
		<Result>
			<HoldingRegister ref="0">0</HoldingRegister>
			<HoldingRegister ref="1">0</HoldingRegister>
		</Result>
	</HoldingRegisters>
	<HoldingRegisters count="1" ref="3">
		<Result>
			<HoldingRegister ref="0">0</HoldingRegister>
		</Result>
	</HoldingRegisters>
	<Discretes count="2" ref="0">
		Result>
			<Discrete ref="0">false</Discrete>
			<Discrete ref="1">false</Discrete>
		</Result>
	</Discretes>
	<Discretes count="1" ref="3">
		Result>
			<Discrete ref="0">false</Discrete>
		</Result>
	</Discretes>
	<Coils count="2" ref="0">
		Result>
			<Coil ref="0">false</Coil>
			<Coil ref="1">false</Coil>
		</Result>
	</Coils>
	<Coils count="1" ref="3">
		Result>
			<Coil ref="0">false</Coil>
		</Result>
	</Coils>
</Request>

Operation Write:

Sample output for operation WRITE

XML

<?xml version="1.0" encoding="UTF-8"?>
<Request>
	<HoldingRegister ref="11">14</HoldingRegister>
	<Coil ref="20">true</Coil>
	<Coil ref="000E1">TRUE</Coil>
</Request>

Sample output in case of an error

XML

<?xml version="1.0" encoding="UTF-8"?>
<listErrors description="Wrong Input values for the elements of this list">
	<HoldingRegister ref="11">xx</HoldingRegister>
	<Coil ref="xxxxx">true</Coil>
	<Coil ref="000B">45</Coil>
</listErrors>