CommFB Library Documentation¶
- Company
3S - Smart Software Solutions GmbH
- Title
CommFB
- Version
3.5.17.10
- Categories
Application|Fieldbus
- Namespace
CommFB
- Author
3S - Smart Software Solutions GmbH
- Placeholder
CommFB
Description 1¶
**Communication Function Blocks on PROFIBUS DP and PROFINET IO**
For PROFIBUS DP and PROFINET IO sets of communication services are defined in IEC 61158. The representation of these services in the application program is dependent of the various controllers and devices provided by different manufactures.
This library implements a set of Communication Function Blocks for communication among programmable controllers and Field Devices over PROFIBUS DP and PROFINET IO respectively.
The following figure gives an overview of the PNO profiles and the placement of this library in the context of the other PNO specifications.

The Communication Function Blocks implemented in this library have a universal interface for PROFIBUS DP as well as PROFINET IO.
Parameters:
Parameters of different Communication Function Blocks with the same or a similar meaning have the same name and data type according the following Table:
Parameter |
Data Type |
Meaning |
REQ |
BOOL |
Request function |
ID |
DWORD |
Identification of a Field Device or a slot / subslot of it |
INDEX |
INT |
Identifier of a process data object |
OFFSET |
INT |
Count of the first byte within IO Data object |
LEN |
INT |
Actual data length of a process data record |
DONE |
BOOL |
Flag that the function has finished successfully |
VALID |
BOOL |
Flag that the function has finished successfully and the received output data are valid |
BUSY |
BOOL |
Flag that the function is still performing its task, its not ready to perform a new task |
ERROR |
BOOL |
Flag that the function has finished with an error |
STATUS |
DWORD |
Completion or error code |
Note
The actual value of ID
should never be manipulated or created,
only use the values created from theses sources described here (see: ID).
The value of ID
can differ depending on the project structure or the driver version !
The INDEX
input addresses a process data record, the LEN
parameter contains the length of a process data record.
Note
The data type INT
is used for both the INDEX
and LEN
parameter though the value range of the parameters
in the IO subsystems may cover 0..65535. The data type INT
is supported by all PLC im-plementations,
the better fitting UINT
is not always supported. The value range of 0..32767 is sufficient for nearly all applications.
The data type INT
was already used in earlier versions of the library specification, and it is kept for compatibility
reason. Nevertheless an INDEX > 32767 may be given on the interface using a negative number or a hexadecimal constant.
The DONE
and the ERROR
outputs pulses only from one invocation of the instance of the Com-munication Function Block.
Contents:¶
- CommFB
- AINFO_TYPE (Union)
- AddressConcept (GVL)
- Addresses
- CNCT (FunctionBlock)
- Constants (GVL)
- DP Address
- DP_AINFO (Struct)
- DP_DIAG (Struct)
- ErrorCode (Enum)
- ErrorCode1_RW (Enum)
- FieldDevice
- GETIO_PART (FunctionBlock)
- PN_AINFO (Struct)
- RALARM (FunctionBlock)
- RALARM_MODE (Enum)
- RDIAG (FunctionBlock)
- RDREC (FunctionBlock)
- SETIO_PART (FunctionBlock)
- WRREC (FunctionBlock)