Lenze DDS v2.3 - Manual (Page 59)

Drive PLC Developer Studio
Programming languages
4-21
l
DDS EN 2.3
4.7.3 Set/ Reset coil
A coil can also be defined as set or reset coil.
•
A variable of a set coil becomes TRUE if the network result is TRUE.
•
A variable of a reset coil becomes FALSE if the network result is FALSE.
•
If the conditions are not fulfilled, the variable does not change.
A set coil (” S” in the coil symbol) can assume ” ON” status, but can then no longer be reset to ” OFF” .
A Reset coil (” R” in the coil symbol) can assume ” OFF” status, but can then no longer be reset to
” ON” .
4.7.4 Function blocks in LD
In addition to contacts and coils, LD allows the input of function blocks and programs.
In the network, function blocks and programs must have an input and output with Boolean values
and can be used at the same locations as contacts, i.e. on the left-hand side of the LD network.
4.7.5 LD as FBD
Use global variables or direct calls if the result of a circuit in LD is to be used to control other
organization units.
Global variable
The result of a circuit can be saved with the help of the coils in a global variable that is then further
used otherwise.
Direct call
The call can be directly installed into your LD network. For this purpose, insert an EN organization
unit (” EN” stands for ” Enable” ).
•
EN organization units are normal operators, functions, programs or function blocks that have
an additional input labelled EN. This input is a BOOL-type input.
•
An EN organization unit will only be evaluated if its EN input is TRUE.
•
An EN organization unit is switched in parallel to the coils, with the EN input being linked to
the connection line between the contacts and the coils. If the status ” ON” is transmitted via
this line, the organization unit will be evaluated normally.
•
Based on such an EN organization unit, networks can be generated as in FBD.
Show/Hide Bookmarks