CTD

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IEC / CEI 1131-3 Compliant

ctd

 

The CTD object represents a DOWN COUNTER. A rising-edge on CD input will decrement the counting by one. The Q output become TRUE when the current counting value is equal  or less than zero.  Applying a TRUE signal on LD (LOAD)  input will load the counter with the value present at input PV ( Asyncronous load ).

The CV output pin reports the current counting value.

 

Net plugs

 

Plug

Description



CD

A rising-edge on this input will decrement the counter by one

 

 

LD

Applying a TRUE signal on this input will load the counter with the value present at input PV

 

 

PV

When the LD pin is asserted, the value applied to this pin will be loaded as current count value. User should use a CONST or  IDENT object to enter numerical constant

 

 

Q

This output become TRUE when the counting is less or equal than zero

 

 

CV

This output reports the current counting value

 

See also : COUNTER , CTU , CTUD , IDENT , CONST