YME Engineering Course

J. SEQUENCE CONTROL FUNCTION
Figure: Sequence Table Processing Flow
♦ Input Processing
The true/false status of the condition signal is determined by performing
condition testing based on the input signal.
♦ Condition Rule Processing
The true/false status of the rule condition is determined by comparing the
true/false status of the condition signal with the Y/N pattern of the
condition rule described in the sequence table.
♦ Action Rule Processing
The action signal output is determined by the Y/N pattern of the action rule
when the status of condition is true.
♦ Output Processing
Status manipulation of the action target is performed based on the
description of the action signal. The status manipulation, start command
transmission, data setting, and status change can be performed to the
contact outputs and other function blocks. There are two types of
sequence tables: step and non-step. Rule processing differs by the type of
sequence table.
J.2.4 ACTION OF STEP SEQUENCE
In a step sequence table, the process control sequence of a phase-step process
is divided into the smallest phase units (steps) of the condition monitoring and
operation, and then these steps are executed one by one. In a step sequence
table, only step label 00 and the rule corresponding to the current step number
are subject to condition testing and operation. The following shows the action of
a step sequence table.
YME Training Center J-6
CS3KR3-ENG 1 ST Edition Jan 2002