com.langner.jmatic2
Class SxPLC

java.lang.Object
  com.langner.jmatic2.SxPLC

public class SxPLC

extends java.lang.Object

This class is used for communication with SIMATIC S5® and S7® PLCs utilizing the S7Functions or the FETCH/WRITE protocol over a TCP or ISO-On-TCP connection. The behaviour of this class is to simplify the access to the data of a PLC. SxPLC is a high-level counterpart to S7Functions of FetchWrite. Data is accessed only through PLCAlias objects rather than binary buffers. These PLCAlias objects are proxies for the real-world process variables.

To use this class, you have to do just a few simple steps:

1. Create an instance of a SxPLC class.

2. Create aconnection to be used by the SxPLC class. If utilizing the S7Functions use the CreateConnection with an instance of a S7FunctionsSettings object. If utilizing a TCP connection use the CreateConnection with an instance of a FetchWriteTCPSettings object. If utilizing a ISO-On-TCP connection use the CreateConnection with an instance of a FetchWriteRFC1006Settings object.

3. Register one or more PLCAlias objects to this instance.

4. Register a SxPLCListener implementation to be informed about value changes.

4. Call the method start to roll the dices. At this point, the SxPLC object will connect to the PLC and call your listener for all variables that have changed since last read. At startup, all values will be initialized. SxPLC reads the data from the PLC in the interval specified with the pollrate and takes care about changes of the values read. If the connection is lost or dropped, the SxPLC object will try to reconnect to the PLC.

5. To write a variable on the PLC, just use the method setValue.

Version:

2.0

Author:

Langner Communications AG

Copyright:

Langner (c) 2001-2005

Constructor Summary

SxPLC()
Creates a new instance of SxPLC

Method Summary

void	addListener(SxPLCListener listener) Adds a listener.
void	CreateConnection(FetchWriteRFC1006Settings settings, PLCModel model) Creats a connection using FetchWrite over ISO-on-TCP.
void	CreateConnection(FetchWriteTCPSettings settings, PLCModel model) Creats a connection using FetchWrite over TCP.
void	CreateConnection(S7FunctionsSettings settings) Creats a connection using S7Functions.
PLCAlias	getAlias(java.lang.String aliasName) Get a previously registered PLCAlias object by name.
PLCAlias[]	getAliases() Get all registered PLCAlias objects.
long	getPollrate() Retrieves the pollrate of this SxPLC object.
IPLCValue	getValue(java.lang.String aliasName) Gets the current value of an PLCAlias object.
void	registerAlias(PLCAlias alias) Register a new PLCAlias object.
void	registerFromFile(java.lang.String filename) RegisterFromFile uses an Excel CSV file to specify the PLC memory layout.
void	removeListener(SxPLCListener listener) Remove a previously added Listener.
void	setPollrate(long ms) Sets the pollrate for this SxPLC object.
void	setValue(java.lang.String aliasName, byte[] value) Sets a value into a PLCAlias object.
void	setValue(java.lang.String aliasName, java.lang.Object value) Sets a value into a PLCAlias object.
void	start() This method starts the communication with the PLC.
void	stop() This method stops the communication with the PLC.
void	unregisterAlias(java.lang.String aliasName) Unregister a previous registered PLCAlias.
void	unregisterAllAliases() Unregisters all previous registered PLCAliases.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SxPLC

public SxPLC()

Creates a new instance of SxPLC

Method Detail

CreateConnection

public void CreateConnection(S7FunctionsSettings settings)
                      throws JMaticException

Creats a connection using S7Functions. This constructor initializes the properties with the supplied values.

Parameters:

settings - Object with the connection settings

Throws:

JMaticException

CreateConnection

public void CreateConnection(FetchWriteTCPSettings settings,
                             PLCModel model)
                      throws JMaticException

Creats a connection using FetchWrite over TCP. This constructor initializes the properties with the supplied values.

Parameters:

settings - Object with the connection settings

model - Specifies the model of the PLC to be connected to.

Throws:

JMaticException

CreateConnection

public void CreateConnection(FetchWriteRFC1006Settings settings,
                             PLCModel model)
                      throws JMaticException

Creats a connection using FetchWrite over ISO-on-TCP. This constructor initializes the properties with the supplied values.

Parameters:

settings - Object with the connection settings

model - Specifies the model of the PLC to be connected to.

Throws:

JMaticException

addListener

public void addListener(SxPLCListener listener)

Adds a listener.

Parameters:

listener - The listener to be added.

removeListener

public void removeListener(SxPLCListener listener)

Remove a previously added Listener.

Parameters:

listener - The listener to be removed.

setPollrate

public void setPollrate(long ms)

Sets the pollrate for this SxPLC object.

Parameters:

ms - The pollrate in milliseconds.

getPollrate

public long getPollrate()

Retrieves the pollrate of this SxPLC object.

Returns:

The pollrate in milliseconds.

start

public void start()
           throws JMaticException

This method starts the communication with the PLC.

Throws:

JMaticException - in case of an unrecoverable error.

stop

public void stop()
          throws JMaticException

This method stops the communication with the PLC.

Throws:

JMaticException - in case of an unrecoverable error.

getAlias

public PLCAlias getAlias(java.lang.String aliasName)

Get a previously registered PLCAlias object by name.

Parameters:

aliasName - The alias name of the object. See registerAlias

Returns:

The PLCAlias object or null if not found.

getAliases

public PLCAlias[] getAliases()

Get all registered PLCAlias objects.

Returns:

Array of all registered PLCAlias objects.

registerFromFile

public void registerFromFile(java.lang.String filename)
                      throws JMaticException

RegisterFromFile uses an Excel CSV file to specify the PLC memory layout.
Every line specifies one plc variable (operand). Syntax is

# Comment
Operand.Offset.[Count.]Data_type, Variable_name

• Offset is always byte offset
• Number of elements (Count) is required only for STRING (S5-String) variables
• Comments must begin with '#'

Operand types

Operand	Meaning
DBn	Data block. "n" is the DB number
O	Output
I	Input
M	Memory Byte
C	Counter
T	Timer

Data types

Data type	Meaning	Possible operands
BOOL0-BOOL7	Boolean with offset X.0-X.7 (X represents the byte offset)	DB, O, I
BYTE	Byte	DB, O, I
CHAR	ASCII character	DB, O, I
INT	Signed integer	DB, O, I
DINT	Signed long integer	DB, O, I
WORD	Unsigned short	DB, O, I
DWORD	Unsigned long integer	DB, O, I
REAL	Float	DB, O, I
S7STRING	String (only S7 plc)	DB
STRING	String	DB
DATE	IEC Date	DB
DATE_AND_TIME	Date and Time (8 Byte)	DB
TIME	IEC Time	DB
S5TIME	Time type of S5 plc	DB
TIME_OF_DAY	Daytime	DB

Creating a configuration file
There are three ways to create the configuration file.

1. Using the Langner tool S7-Projectimport which is part of the JMatic distribution. This is the easiest and most relieable way because it eliminates errors. In order to use the Step7 project import, you must have access to the Step7 files as created with SIMATIC manager. In this project you must open the S7 project file "*.s7p".
2. Create the file with MS Excel.
3. Create the file in a simple text editor.

Created with text editor	Created with Excel
#Var address, var name DB1.O0.BOOL0, boolVar_0 DB1.O0.BOOL1, boolVar_1 DB1.O0.BOOL2, boolVar_2 DB1.O10.L96.S7STRING, errormessage DB2.O0.INT, Pump_1 DB3.O0.INT, Pump_2 DB12.O2.INT, Yield DB12.O4.INT, TargetQuantity I.O8.WORD, InputWord 8 O.O8.WORD, OutputWord 8 M.O1.BYTE, MB_1 C.O2.WORD, counter_1 T.O2.WORD, timer_2

Parameters:

filename - The path and name of the csv file to be used as input.

Throws:

JMaticException

registerAlias

public void registerAlias(PLCAlias alias)
                   throws JMaticException

Register a new PLCAlias object. If a PLCAlias object with the same name is already registered, it will be overwritten.

Parameters:

alias - The PLCAlias object to register.

Throws:

JMaticException - in case of an unrecoverable error.

unregisterAlias

public void unregisterAlias(java.lang.String aliasName)
                     throws JMaticException

Unregister a previous registered PLCAlias.

Parameters:

aliasName - The name of the PLCAlias.

Throws:

JMaticException

unregisterAllAliases

public void unregisterAllAliases()
                          throws JMaticException

Unregisters all previous registered PLCAliases.

Throws:

JMaticException

getValue

public IPLCValue getValue(java.lang.String aliasName)

Gets the current value of an PLCAlias object. It's a shortcut for getAlias().getValue().

Parameters:

aliasName - The name of the PLCAlias.

Returns:

IPLCValue object that contain the value or null if not found.

setValue

public void setValue(java.lang.String aliasName,
                     byte[] value)
              throws JMaticException

Sets a value into a PLCAlias object. This function must be used only to a PLCAlias object of type PLC_BINARY.

Parameters:

aliasName - The name of the PLCAlias object.

value - The value to set/write.

Throws:

JMaticException - in case of an error.

setValue

public void setValue(java.lang.String aliasName,
                     java.lang.Object value)
              throws JMaticException

Sets a value into a PLCAlias object.

Parameters:

aliasName - The name of the PLCAlias object.

value - The value to set/write.

Throws:

JMaticException - in case of an error.