beautypg.com

Rising edge detector (r_trig), C.1.12 rising edge detector (r_trig) – Nematron Pointe Controller User Manual

Page 347

background image

Pointe Controller User Guide

Appendix C: Ladder Diagram Block Reference

345

Param

Name

Config

Var Type

Description

CLK

Clock

req

%IX

%MX

%QX

T_DONE

The input value.

Q

Output

req

%IX

%MX

%QX

The output value that is triggered
when the input value transitions
from 1 to 0.

C.1.12 Rising Edge Detector (R_TRIG)

When used in a Ladder Diagram, the R_TRIG block waits for an input bit to
change from 0 to 1 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 0 to 1. 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 0 and transition again to 1
before Q can be triggered again.