Technical data

SFBs for Compact CPUs
System Software for S7-300/400 System and Standard Functions - Volume 2/2
28-48 A5E00739858-01
28.9 Sending Data (512(R)) with SFB 63 "SEND_RK"
Description
You can send a data from a data block via SFB SEND_PTP (SFB 63).
The send operation is executed after the block is called and a positive edge on
control input REQ.
The range of data to be transmitted is determined in SD_1 (DB number and start
address). The length of the data block is determined in LEN.
In the SFB you also declare the receive range of the partner station. The CPU
enters this information in the message frame header (refer also to appendix F) and
transfers it to the partner.
The target is specified by the CPU number R_CPU (only relevant for
multiprocessor communication), the data type in R_TYPE (data blocks (DB) and
expanded data blocks (DX)), the data block number in R_DBNO and the offset in
R_OFFSET to where the first byte is to be written.
In R_CF_BYT and R_CF_BIT, declare the connection memory byte and bit on the
partner CPU.
In parameter SYNC_DB, declare the DB in which the data that you used in all
SFBs for the initialization during startup and synchronization is to be stored. The
DB numbers must be identical for all SFBs in your user program.
To enable the SFB to process the job, you must call it with R(Reset)=FALSE. At
the positive edge on control input R the current send operation is cancelled and the
SFB is reset to basic state. A cancelled job is terminated with an error message
(STATUS output).
For your submodule, you declare the I/O address, which you specified in "HW
Config", in LADDR.
DONE is set TRUE if the job was terminated without error, or ERROR is set TRUE
if the job was terminated with an error.
Once the job was processed with DONE = TRUE, the data are sent to the
communication partner that confirms them positively and passes them on to the
partner CPU.
In STATUS, the CPU indicates an error or, as a result of a warning, the respective
event ID.
DONE or ERROR/STATUS are also output when the SFB is RESET (R=TRUE).
The binary result BIE is reset if an error has occurred. The status of the binary
result is TRUE if the block was terminated without error.
Note
A parameter check is not included in the SFB. If the CPU is assigned the wrong
parameters it might jump to STOP mode.
Instance DB
The SFB SEND_RK operates in combination with an instance DB. The DB number
is passed on with the call. Access to the data in the instance DB is not allowed.