Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller Bedienungsanleitung PDF herunterladen (Seite 67)

3.2 EXAMPLE 1 - LOGICAL ONESHOT

A logical oneshot can be used to toggle a Contact Closure Output (CCO) or reset a totalizer. As

shown in Figure 3-1, a oneshot pulsed output can be generated from a Logic module. Generating

a pulsed output from a Logic module requires comparing a logical input from the previous scan

with a second logical input from the current scan. This is possible because the individual modules

are executed in the fixed order given in Figures 2-1 through 2-3. This means that those modules

not yet processed in the current scan time still contain outputs from the previous scan iteration.

Therefore, if one input to a Logic module references the output from a subsequent module in the

execution order, it will receive that input value delayed one execution scan. The low-to-high output

pulse transition occurs when the current scan and previous scan inputs are true for the logic func-

tion being performed. The pulse remains high until the previous scan input from the subsequent

module changes. When that module is executed in the current scan the high-to-low pulse transi-

tion occurs.

Figure 3-1. Logical Oneshot

FCS 53MC5000 Flexible Control Strategies

3-2

EX1

1 2 ... 62 63 64 65 66 67 68 69 70 71 72 ... 200 201

Keine Kommentare

Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller Bedienungsanleitung Seite 67