ABB RER670 Applications Manual page 372

Section 14
Logic
366
IEC09000695 V2 EN-US
Figure 155: Example designation, serial execution number and cycle time for
logic function
IEC09000310 V2 EN-US
Figure 156: Example designation, serial execution number and cycle time for
logic function that also propagates timestamp and quality of input
signals
The execution of different function blocks within the same cycle is determined by
the order of their serial execution numbers. Always remember this when
connecting two or more logical function blocks in series.
Always be careful when connecting function blocks with a fast
cycle time to function blocks with a slow cycle time.
Remember to design the logic circuits carefully and always check
the execution sequence for different functions. In other cases,
additional time delays must be introduced into the logic schemes to
prevent errors, for example, race between functions.
IEC09000695_2_en.vsd
IEC09000310-2-en.vsd
Railway application RER670 2.2 IEC
1MRK 506 375-UEN A
Application manual