User manual

Publication LOGIX-AP010B-EN-P - May 2010 37
Software Conversions - Program Structure Chapter 2
In Step 5, OB1 is the first code executed. In RSLogix 5000 software, the first
routine executed can be selected by the programmer. It is indicated in the
project tree by the icon beside the Main Routine. When converting a PLC
application from Step 5 to RSLogix 5000 software, function calls originally in
S5 OB1, are commonly placed in the designated RSLogix 5000 Main Routine.
The following window shows how routines appear under the continuous task
in the RSLogix 5000 project tree. The Main Routine designated as the start-up
routine is indicated by the icon .
The following example shows how three PBs called in from OB1 could be
converted into RSLogix 5000 software.
In S5 the PBs are given symbol names and called from OB1. In RSLogix 5000
software, the routines are called from the Main Routine.