Watlow LogicPro - Manual (Page 101)

LogicPro User’s Guide Chapter 8: Ladder Diagrams
Doc.# 28002-00 Rev 3.00 Watlow Anafaze 85
On To Off Transitional Contact
The [On to Off Transitional Contact] tool allows you to
insert on to off transitional contacts into the program window.
The On To Off Transitional Contact is sometimes known as
the Negative Transitional Contact.
During a single evaluation of the Ladder diagram, if the
Variable associated with this contact changes from True to
False, then the contact will close for this cycle only. Thus
allowing electricity to flow to the next element on the rung.
For all other conditions this contact remains in the Open state.
To use On to Off Transitional Contact:
1. Select the [On to Off Transitional Contact] tool .
2. Position the pointer where you want the contact placed
and click.
Normal Coil
The [Normal Coil] tool allows you to insert normal output
coils into the program window.
The Normal Coil is set to On when all of the contacts on the
Ladder rung pass power to the coil from the left power rail.
This coil or Function Block remains On until one of the
contacts opens and stops sending power to the coil.
To use the Normal Coil:
1. Select the [Normal Coil] tool.
2. Position the pointer where you want the coil placed and
click.
Latched Coil
The [Latched Coil] tool allows you to insert latched coils
into the program window
The Latched Coil, sometimes known as a Set coil, is set to On
when all of the contacts or Function Blocks on the Ladder
rung pass power to the coil from the left power rail. This coil
remains latched On until it is reset by a Reset (Unlatched)
coil.