Technical data

Table Of Contents
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
14-1
14 SFCs and SFBs for Updating the Process
Image and Processing Bit Fields
14.1 Updating the Process Image Input Table with SFC 26
"UPDAT_PI"
Description
With SFC 26 "UPDAT_PI" (update process image), you update the OB1 process
image input table ( = process image section 0) or a process image input section
defined with STEP 7.
If you configured the repeated signaling of I/O access errors for the system process
image table update, the selected process image table will be updated constantly by
SFC 26.
Otherwise, SFC 26 will only update the process image table when the selected
process image section is not updated by the system, in other words:
When you have not assigned this process image section to an interrupt OB,
or
When you selected process image section 0 and have disabled updating of the
OB1 process image section in the configuration.
Note
Each logical address you assign to an input process image partition with STEP 7
no longer belongs to the process image input table of OB 1.
When you update an input process image partition with SFC 26, you may not
update it with SFC 126 "SYNC_PI" as well.