Specifications

Appendix A: Troubleshooting Positive Transition Contact ( Rise )
VisiLogic: Getting Started 105
At the end of a scan, the Positive Transition Contact is reset to ON (logic 1).
The Positive Transition Contact is re-activated when the linked signal turns
from OFF to ON.
Note
•
Execution time for Positive and
Negative Transition contacts is
considerably greater than the execution time for direct and
indirect contacts. However, you can decrease the amount of
transitional contacts in your program.
Decreasing the Number of Transitional Contacts
You can use
the coil of a
bit operand
to save the
positive
transition of
a contact,
and then use
the direct
contact of
the operand
in your
program.
You can use the Direct Contact of SB 13 instead of using the
Positive Transition Contact of SB 3, and the Direct Contact of SB
15 instead of using the Positive Transition Contact of SB 7.
SB 3 is a pulse generator, with a cycle time of 1 second and a
duty cycle of 50% (0.5 seconds ON, 0.5 seconds OFF).
SB 13 is the Positive Transition (rising edge) contact of SB 3.
SB 7 is a also a pulse generator, with a cycle time of 0.1 second.
SB 15 is the Positive Transition (rising edge) contact of SB 7.
Rise/Fall Usage Summary
The
maximum number of
Rise/Fall elements that
is allowed in a
project depends on the controller model. To ascertain how many
elements of each type are in the project, use the Rise/Fall utility on
the View menu.
The sum of the results must not exceed:
V570 – 1024 (0...1023)