Connection

These methods allow controlling the behaviour a Client Object.

Function	Purpose
ConnectTo	Connects a S7Client object to a PLC
Connect	Connects a S7Client object to a PLC with implicit parameters
Disconnect	Disconnects a S7Client
SetConnectionType	Sets the connection type (PG/OP/S7Basic)
SetConnectionParams	Sets Address, Local and Remote TSAP for the connection

ConnectTo

Description

Connects the client to the hardware at (IP, Rack, Slot) Coordinates.

Declaration

public int ConnectTo(String Address, int Rack, int Slot)

Parameters

Name	Type	Note
Address	string	PLC IPV4 Address e.g.: "192.168.1.10"
Rack	int	see table
Slot	int	see table

Return value

• 0 : The Client is successfully connected (or was already connected).

• Other values : see the Errors Code List.

Rack and Slot

In addition to the IP Address, that we all understand, there are two other parameters that index the unit : Rack (0..7) and Slot (1..31) that you find into the hardware configuration of your project, for a physical component, or into the Station Configuration manager for WinAC.

There is however some special cases for which those values ​​are fixed or can work with a default as you can see in the next table.

PLC	Rack	Slot
S7 300 CPU	0	2	almost always, but according to the hw config
S7 400 CPU	not fixed	not fixed	according to the hw config
WinAC CPU	not fixed	not fixed	according to the hw config
S7 1200 CPU	0	0 or 1
S7 1500 CPU	0	0 or 1
WinAC IE	0	0	according to the hw config

Connect

Description

Connects the client to the PLC with the parameters specified in the previous call of ConnectTo() or SetConnectionParams().

Declaration

public int Connect()

Return value

• 0 : The Client is successfully connected (or was already connected).
• Other values : see the Errors Code List.

Remarks

This function can be called only after a previous of ConnectTo() or SetConnectionParams() which internally sets Address and TSAPs.

Disconnect

Description

Disconnects “gracefully” the S7Client from the PLC.

Declaration

public void Disconnect()

Remarks

This function can be called safely multiple times. After calling this function LastError = 0 and Connected = false.

SetConnectionType

Sets the connection resource type, i.e. the way in which the Clients connects to a PLC.

Declaration

public void SetConnectionType(short ConnectionType)

Parameters

Name	Type	Note
ConnectionType	short	See the table

Connection type table

Connection Type	Value	Helper Const
PG	0x01	S7.PG
OP	0x02	S7.OP
S7 Basic	0x03..0x10	S7.S7_BASIC

SetConnectionParams

Description

Sets internally (IP, LocalTSAP, RemoteTSAP) Coordinates.

Declaration

public void SetConnectionParams(String Address, int LocalTSAP, int RemoteTSAP)

Parameters

Name	Type	Note
Address	string	PLC IPV4 Address e.g.: "192.168.1.10"
LocalTSAP	int	Local TSAP (PC TSAP)
RemoteTSAP	int	Remote TSAP (PLC TSAP)

Remarks

This function must be called just before Connect().