Exchanging data using the SIMATIC FB’s
ASCII | 3964R | RK512
16
Parameters for data transfer for SIMATIC S5
The control data or user data to be exchanged is copied to a special PLC memory area
– the data block (DB) – from where the PLC writes the data to the SPI 3 through the DP
master. The data block consists of several data words, whereby data words 0 to 5 (DW0
to DW5) are reserved for internal use. User data always starts at DW6.
The following parameters must be specified when calling the FB’s. The tables indicate
which of the parameters are required for each of the FB’s:
Parameters for address information:
specify the location and length of the address array in the PLC address space.
Parameters for user data:
specify the location of the send/receive data blocks used for exchanging telegrams.
Parameters for processing RK512 telegrams:
specify the send and receive data blocks used for RK512 telegrams.
DW0
Internal use only
DW5
Internal use only
Start of user data
DW6
User data
DW-L
DWX
End of user data
Name Type
Description / Function
present in:
FB200
FB201
FB203
A-A
KF
Starting address of send data area
X
X
X
E-A
KF
Starting address of receive data area
X
X
X
EA-L
KF
Length of I/O area of the SPI 3 (in bytes)
X
X
X
Name Type
Description / Function
present in:
FB200
FB201
FB203
DB
B
Data block for sending/receiving telegrams
X
X
DW-L
W
Length of data to send/receive (in bytes)
X
X
Name Type
Description / Function
present in:
FB200
FB201
FB203
DB-Q
B
Data block for received RK512 telegrams
X
DB-Z
B
Data block for RK512 telegrams to be sent
X
