Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller FLEXIBLE CONTROL STRATEGIES - Manual (Page 9)

module can not be connected to the numeric input of another (black output circles connect only to
black input diamonds and open output circles connect only to open input diamonds).
In the illustration shown, the Logic A module can accept only logical (0/1) input values at A and B.
If a 2 were entered into B129, it would cause the logic module to execute the A AND B function on
the inputs. The A AND B function is listed in the
Logic Functions table after the function code 2.
Depending on the inputs A, B, the output value would be a logical 0 or 1 value in datapoint L097.
This value can be accessed by other FCS modules that are wired to it. The value to a module in-
put can only be single sourced (coming from only one output); however, the output value may be
accessed by several other modules as their inputs.
2.3 MODULE EXECUTION ORDER
Figures 2–1, 2–2, and 2–3 on the following pages show the execution order of the modules for con-
trol strategies with one loop, two loops, and four loops. In each figure, the order of execution is top
to bottom, left to right.
Also, on Figure 2-1, there are three output modules: Assign ANOs, Assign CCOs, and Assign
Status. These three modules are last in the execution order irrespective of the number of loop se-
quences (one, two, or four loop sequences). Notice there is an empty block before them that is an
entry point from the outputs of the two and four loop execution sequences in Figures 2-2 and 2-3.
As each module executes, it generates new output values based on the inputs supplied. If an input
signal is obtained from an output that is calculated later in the sequence, the input value will reflect
the output calculated in the previous scan, thus introducing a delay into the current module calcula-
tion. In most cases the delay of one input relative to the other inputs of a module is not significant
because the numeric signals are continuous; however, signal backtracking should be avoided
whenever possible.
FCS 53MC5000 Flexible Control Strategies
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