ISPSoft User Manual

Chapter 8 Ladder Diagram
(b)
‣ Boolean value:
AH500: SM400 (normally-open contact), or SM401 (normally-closed contact) is used.
DVP: M1000 (normally-open contact), or M1001 (normally-closed contact) is used.
If users want to use a symbol whose data type is ARRAY, the expression format is
Identifier[Index]. Generally speaking, an index is a decimal constant. The indexes in a ladder
diagram can not be symbols. The minimum index value for a symbol whose data type is
ARRAY must be 0, and the maximum index value for a symbol whose data type is ARRAY can
not be larger than the number of elements in the array.
8.2.3 Typing Instructions
Users can add devices, applied instructions and function blocks to a ladder diagram in ISPSoft by
typing instructions.
(1) Select a position in which an object will be inserted in a working area.
(2) Type an instruction. As soon as the instruction is typed, a box which can be edited appears.
After the typing of the instruction is complete, users can press Enter on the keyboard or click
OK at the right side of the box. (The instruction is case-insensitive.)
Besides, contacts and coils can be created by typing simple instructions. Please refer to the
following figures. (The instructions typed are case-insensitive.)
• Inserting a normally-open contact (contact A): “A Device address”
• Inserting a normally-closed contact (contact B): “B Device address”
• Inserting an output coil (OUT): “O Device address”
8.2.4 Inserting Applied Instructions and Function Blocks
The applied instructions and function blocks in a ladder diagram in ISPSoft are represented by
blocks. The pins of a block representing an applied instruction include the pins corresponding to the
operands specified in the applied instruction and an En pin. The pins of a block representing a
function block include the pins corresponding to the symbols declared in the function block and an
En pin. The En pin of a block representing an applied instruction or a function block is connected to
the logic state preceding the En pin. If the logic state connected to the En pin of a block representing
an applied instruction or a function block is ON, the applied instruction or the function block will be
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