Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 91
4.4 Contacts
A contact is used to monitor the state of a reference address. Whether the contact passes power
flow depends on positive power flow into the contact, the state or status of the reference address
being monitored, and the contact type.
A reference address is ON if its state is 1; it is OFF if its state is 0.
Contact Passes Power to Right...
if the preceding continuation coil is set ON
if its associated BOOL or WORD variable has a point fault
if the high alarm bit associated with the analog (WORD) reference is
ON
if the low alarm bit associated with the analog (WORD) reference is
ON
if its associated BOOL or WORD variable does not have a point fault
if associated BOOL variable is OFF
if associated BOOL variable is ON
(negative transition contact) if BOOL reference transitions from ON
to OFF. Updated every time it is called.
(negative transition contact) if BOOL reference transitions from
ON to OFF. Updated once per scan.
(positive transition contact) if BOOL reference transitions from OFF
to ON. Updated every time it is called.
(positive transition contact) if BOOL reference transitions from OFF
to ON. Updated once per scan.
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