Nematron Pointe Controller - Manual (Page 346)

Appendix C: Ladder Diagram Block Reference Pointe Controller User Guide
344
Configuration Reference
Any Memory Bit (%MX) or Output Bit (%QX) tag may be associated with the
block.
C.1.11 Falling Edge Detector (F_TRIG)
When used in a Ladder Diagram, the F_TRIG block waits for an input bit to
change from 1 to 0 and triggers an output bit when it does.
Select the tool (from the Relays and Coils toolbar) and click on a ladder rung
to insert the following block:
Once the block is inserted, you can double-click on it to configure it.
Functional Description
This block always passes the Enable input state (EN) through to the Enable Out
output state (ENO) without change; when EN becomes on, ENO is turned on, and
when EN becomes off, ENO is turned off.
When EN becomes on, the block function is executed: the Clock input (CLK) is
monitored for a transition from 1 to 0. When a transition is detected, the Output
(Q) is triggered; i.e., Q is set to 1 for a single execution of the block, after which it
is immediately reset to 0.
The block function is executed every time the ladder is scanned , so long as EN
remains on. However, Q is triggered only when a transition in CLK is detected.
After Q has been triggered, CLK must be reset to 1 and transition again to 0
before Q can be triggered again.
Configuration Reference
The parameters of this block are described in the following table:
Param Name Config Var Type Description
EN Enable no - The state of the rung (off/on)
received from the left.
ENO Enable
Out no - The state of the rung (off/on)
passed to the right.