Watlow LogicPro Manual do Utilizador descarregar pdf (Página 128)

Chapter 9: Function Block Diagrams LogicPro User’s Guide

112 Watlow Anafaze Doc.# 28002-00 Rev 3.00

4. Fill in the Execution Order field. An execution order

is automatically assigned to the function blocks

(determined by the order in which you created them) but

it is also possible to change the execution order of the

function blocks at any time.

Execution order is not bound by the apparent layout of the

program. In the example shown in Figure 9.5, the function

block named two is assigned to be first in the execution order,

then three, and then one. While the CTU function block

called two depends on one it can be executed first because all

values are saved from the last cycle during which the program

ran and those values are applied again. So, while it might seem

strange that two runs first, being dependent upon input from

one, the last value that was passed to two from one is used

instead of new data.

Figure 9.5 Execution Order in FBD

Cutting, Copying, Pasting, and Deleting

When cutting or copying a function block, it is necessary to

make sure that all the function block’s input and output

Variables are also selected. You can tell that they are selected

if they appear with “handles” around them, as shown in

Figure 9.6 on page 113.

1 2 ... 123 124 125 126 127 128 129 130 131 132 133 ... 295 296

Sem comentários

Watlow LogicPro Manual do Utilizador Página 128