ISPSoft User Manual

ISPSoft User Manual
12.2.2 Transitions
When a transition is true, the active step immediately before the transition becomes inactive and the
step immediately after the transition becomes active. A transition can be true anytime, but for a
transition to activate the step following it, the step preceding it must be active when the transition is
true.
In ISPSoft, a transition can be a Boolean device or symbol, or a program code. If a transition is a
logical operation, users can create a transition program, and assign the program to the transition.
The transition programs which are created are listed in the project management area.
The programming languages which can be used to create transition programs include ladder
diagrams, instruction lists, function block diagrams, and structured texts. The Boolean state in a
transition program must be sent to a symbol name which is the same as the transition program
name, whether the programming language used to create the transition program is a ladder diagram,
an instruction list, a function block diagram, or a structured text. The symbol does not need to be
declared. However, if there is a symbol name in a symbol table which is the same as a transition
program name, an error occurs when the program is compiled. Besides, applied instructions and
function blocks can not be used in a transition program, but comparison contacts and block logic
instructions (NP, PN, and INV) can be used in a transition program.
If the programming language used to create a transition program is a ladder diagram, the program
code of the transition program must be composed of one network, and the output contact must be
assigned a symbol name which is the same as the transition program name. Besides, multiple
outputs are not allowed in a transition program created by means of a ladder diagram.
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