Symbol Name
Description
Output for
TRUE
input
Normally open
contact
The output of the normally open contact is the same as the activation status.
A normally open contact can represent a normally open switch or a pressure
switch.
TRUE
Normally
closed contact
The output of the normally closed contact is the opposite of the activation status.
A normally closed contact can represent a normally closed switch or a
pressure switch.
FALSE
Rising edge
contact
The output of the rising edge contact is the same as the activation status for one
scan of the contact. After the contact has been scanned the output will change to
FALSE until it is activated again.
A rising edge contact can represent a one shot push-button.
TRUE (one
scan)
Falling edge
contact
The output of the falling edge contact is the opposite of the activation status for
one scan of the contact. After the contact has been scanned the output will change
to TRUE until it is activated again.
A falling edge contact can represent a one shot push-button.
FALSE
Coils
Coils, also referred to as outputs, are always next to the right vertical rail. The table below summarises the different coils
available in CustomLogic:
Symbol Name
Description
Output for
TRUE input
Normally
open coil
The output of the normally open coil is the same as the input.
A normally open coil can activate a relay to start a pump or start an
internal system element.
TRUE
Normally
closed coil
The output of the normally closed coil is the opposite of the input.
A normally closed coil can activate a relay, start a pump or start an internal
system element.
FALSE
Set coil
The output of the set coil changes to TRUE when the input is TRUE. The
output will remain TRUE until a reset coil is activated (even if the input is no
longer TRUE).
A set coil can activate an overhead light or start a pump.
TRUE
(continuously)
Reset coil
The output of the reset coil changes to FALSE when the input is TRUE. The
output will remain FALSE until a reset coil is activated (even if the input is no
longer TRUE).
A reset coil can deactivate an overhead light or stop a pump.
FALSE
Jump coil
This type of coil jumps to another block in the ladder logic. The remainder of
the vertically scanned rung block, in which the jump coil appears and all the
rung blocks up until the destination rung block, are not executed.
TRUE
Function blocks
The table below summarises the different function blocks available in CustomLogic:
PPM 300 PICUS manual 4189341080 UK
www.deif.com
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