Siemens SIMATIC S7-400 Configuration And Use Manual page 80

Interfaces, Networks and Data Communication for the S7-400
SFC
FB 3 READ
FB 6 WRITE
FB 4 REPORT
FB 2 IDENTIFY
FB 5 STATUS
SFBs for Point-to-Point Connections
Using the point-to-point connection via CP 441, you can link to all communication
partners that can handle the 3964(R), RK 512 or ASCII procedures. Non-Siemens
protocols are implemented with loadable drivers.
The communication SFBs require a point-to-point connection configured with
STEP 7. This connection runs from the CPU to the CP.
The communication SFBs that you can use are listed in the following table:
SFC
SFB 12 BSEND
SFB 13 BRCV
SFB 14 GET
SFB 15 PUT
SFB 16 PRINT
SFB 22 STATUS
Function blocks for specific CPs are also supplied with the respective CPs.
5-16
This FB can be used to read a variable from a communication partner
without having to place a corresponding FB in the communication
partner.
This FB can be used to write a variable to a communication partner
without having to place a corresponding FB in the communication
partner.
Sends a structured variable to the communication partner
without acknowledgment.
Reads the identification of a non-Siemens system.
Reads the status of a remote device on request.
Transfer of a data block to the communication partner. The
point-to-point CP acknowledges receipt of the data.
Reads data from a communication partner.
Writes data to a communication partner.
Sends a message containing up to four variables to a printer.
Provides the status of the CPs and the RS 232 interface.
Description
Description
Automation System S7-400 Configuration and Use
A5E00442711-02