2008

Table Of Contents
Generate PLC layout modules
AutoCAD Electrical can generate any of hundreds of different PLC I/O modules
on demand, in a variety of different graphical styles, all without a single,
complete I/O module library symbol resident on the system. Modules
automatically adapt to the underlying ladder rung spacing, whatever that
value might be, and can even be stretched or broken into two or more pieces
at insertion time. This is all possible because AutoCAD Electrical generates
PLC I/O modules through a parametric generation technique driven by a PLC
database (ACE_PLC.MDB).
The PLC database contains not just the stack sequence but also text values to
annotate onto each symbol in the stack. As AutoCAD Electrical builds the
module, it reads the underlying ladder rung spacing and spreads the stack out
or compresses it to match the rung spacing. During the insertion process, in
AutoCAD Electrical, you can interrupt it to break the module and then restart
it at a different location.
Parametric PLC symbols vs. Full Units
Parametric PLC symbols are stored in the \Program Files
[(x86)]\Autodesk\Acade {version}\libs\jic1\ subdirectory (or \Program Files
[(x86)]\Autodesk\Acade {version}\libs\jic125\ for 0.125 height version) along
with all of the other AutoCAD Electrical component symbols. Their file names
begin with the characters "HP" (Horizontal ladder rungs / PLC) or "VP" (Vertical
ladder rungs) followed by a digit that corresponds to a PLC I/O style number.
Each symbol is a building block with a different arrangement of attributes and
wire connection points. AutoCAD Electrical selects the appropriate symbols
to use, stacks them together in the order defined by the data file, and produces
a completed I/O module.
The PLC database file (ace_plc.mdb) is used to drive the PLC I/O module
generation process. You can modify the PLC database file manually or using
the PLC Database File Editor (page 232)(recommended method). The AutoCAD
Electrical PLC database file (ace_plc.mdb) is installed in the C:\Documents
and Settings\{username}\My Documents\Acade {version}\AeData\Plc
subdirectory.
Each Parametric PLC symbol is a building block with a different arrangement
of attributes and wire connection points. AutoCAD Electrical selects the
appropriate symbols to use, stacks them together in the order defined by the
parametric data file, and produces a completed I/O module. AutoCAD Electrical
inserts the symbols based upon the underlying ladder's rung spacing, explodes
218 | Chapter 5 PLC