Introduction.

Workshop PG5
Project management
6.7 Transitions
In a transition you put program parts which only have to run until a certain
situation occurs.
For example, you could read the characters from a serial port until a special
character arrives, or you heat-up the dryers of a machine until they are
warm enough to start the installation.
The transition is always finished by an ETR command. The transition is repeated
endlessly as long as the ETR is low.
Example: The Flag 2 is toggled with each program cycle until the input 0 is
high.
FUPLA:
IL:
The " “End Transition"
FBox is called here
The STH instruction sets the ACCU to
a high state, once the input I 0 goes
high. The transition is considered finished
as soon as the ACCU is high at
the end of the transition.
• You don't have to insert a program in every transition. A transition without a
program is always true and will be skipped.
• Transitions written in Instruction List: The ACCU is always high at the beginning
of a transition or a step.
• 2000 steps and transitions can be used to build up to 32 Sequential Blocks.
PG5-06-E.doc © Saia-Burgess Controls Ltd. Page 6-9