Testing Functions And Diagnostics - Siemens SIMATIC S7-300 Series Reference Manual

1.3 Test Functions and Diagnostics
The CPUs provide you with:
S Testing functions for commissioning
S Diagnostics via LEDs and STEP 7.
1.3.1 Testing Functions
The CPUs offer you the following testing functions:
S Monitor Variables
S Modify Variables
S Forcing (note the differences between CPUs)
S Monitor block
S Set Breakpoint
Details on the testing functions are found in the STEP 7 Online Help.
Important for the Status FB!
The STEP 7 function "Status FB" increases CPU cycle time!
In STEP 7 you can specify a maximum permissible increase in cycle time (not
CPU 318-2). In this case, in STEP 7 you must specify process mode for the CPU
parameters.
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
A5E00111190-01
CPUs
1-19