View source for S7-SoftPLC:Setting the User SFC's/FC's within the PLC43.INI

In the section [SF] there is the possibility to add user defined SFC's/SFB's to ''S7-SoftPLC''. ''S7-SoftPLC'' allows the user to use up to 100 DLLs with user defined system functions (SFC) or functions (FC). Every DLL can contain multiple SFCs or FCs. These SFC/FC can be created by the user in C++, if a certain specification is kept.

By integrating own SFC/FC, the function pool can be expanded by own application specific code parts (technology functions, know-how protection, special hardware components). If the blocks are transferred with the PU to the PLC, the PLC keeps the C++ created internal blocks.

Examples for creating own SFC/FC-DLLs are available at the IBH''softec'' support.

{| class="wikitable"
|-
! Keyname !! Value area !! Default value !! Description
|-
|style="width: 5em"| SF00 ||style="width: 7em"| SFCnnn.DLL ||style="width: 5em"| --- ||style="width: 25em"| File name of user defined SFC/FC
|-
| SF01 || SFCnnn.DLL || --- || File name of user defined SFC/FCC
|-
| SF02 || SFCnnn.DLL || --- || File name of user defined SFC/FC
|-
| ... ||  ||  ||
|-
| SF99 || SFCnnn.DLL || --- || File name of user defined SFC/FC
|}

== Enable hardware ports ==

If a user SFC/FC accesses a hardware port of the PC directly, it has to be mentioned, that no direct access of the PC hardware is allowed with Windows<sup>®</sup> 2000 and Windows<sup>®</sup> XP. To allow direct hardware access, the drivers of ''S7-SoftPLC'' can obtain the permission from the operating system. To do so, the section [IO-PORTS] has to be added in the file PLC43.INI.

Below, beginning with the address 0x0378, normally the printer port, 4 ports are enabled for direct port access.

 [IO-PORTS]
 378=4

For the serial port COM1, normally at address 0x03F8 with a lenght of 8 bytes, the entry would look like this:

 [IO-PORTS]
 3F8=8

Alternatively the I/O-port driver (ioport.dll) can be used as well.