ABB REG670 Applications Manual page 615

1MRK 502 071-UEN -
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
Execution of functions as defined by the configurable logic blocks runs according to
a fixed sequence with different cycle times.
For each cycle time, the function block is given an serial execution number. This is
shown when using the ACT configuration tool with the designation of the function
block and the cycle time, see example below.
IEC09000695 V2 EN
Figure 304: Example designation, serial execution number and cycle time for
logic function
IEC09000310 V2 EN
Figure 305: 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
Section 16
Logic
609