Technical data

Table Of Contents
SFCs for Distributed I/Os or PROFINET IO
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
16-17
Input Parameter RECORD
The CPU evaluates the actual length of the diagnostic data that were read as
following:
If the length specified for RECORD is less than the number of data bytes
supplied, the data are discarded and a corresponding error code is entered in
RET_VAL.
If the length specified for RECORD is greater than or equal to the number of
supplied data bytes, the data are accepted in the destination area and the
actual length is entered in RET_VAL as a positive value.
Note
You must make sure that the actual parameters of RECORD match in all calls belonging to
a job.
A job is uniquely identified by the LADDR input parameter.
Standard Slaves with more than 240 Bytes of Diagnostic Data
With standard slaves on which the number of standard diagnostic data is between
241 and 244 bytes, note the following points:
If the length specified for RECORD is less than 240 bytes, the data are
discarded and the corresponding error information is entered in RET_VAL.
If the length specified for RECORD is greater than or equal to 240 bytes, the
first 240 bytes of the standard diagnostic data are transferred to the destination
area and the overflow bit is set in the data.
Output Parameter RET_VAL
If an error occurs while the function is being executed, the return value contains
an error code.
If no error occurs during the data transfer, RET_VAL contains the length of the
data read in bytes as a positive number.
Note
The amount of data read in a DP slave depends on its diagnostic status.
Error Information
How to evaluate the error information of the RET_VAL parameter is explained in
Evaluating Errors with the Output Parameter RET_VAL. This chapter also contains
the general error information for the SFCs. The error information specific to SFC 13
is a subset of the error information for SFC 59 "RD_REC," see Reading a Data
Record with SFC 59 "RD_REC"