CTD
The function block CTD is a down counter.
Inputs
VAR_INPUT
CD : BOOL; (* Count Down on rising edge *)
LOAD : BOOL; (* Load Start Value *)
PV : WORD; (* Start Value *)
END_VARName | Type | Description |
|---|---|---|
CD | BOOL | Counting down on rising edge |
LOAD | BOOL | Load start value. |
PV | Word | Start value |
Outputs
VAR_OUTPUT
Q : BOOL; (* Counter reached 0 *)
CV : WORD; (* Current Counter Value *)
END_VARName | Type | Description |
|---|---|---|
Q | BOOL | If LOAD = TRUE, the counter variable CV is initialized with the upper limit PV. If CD has a rising edge from FALSE to TRUE, CV is decremented by 1 as long as CV is greater than 0. (i.e. if no underflow is caused) |
CV | WORD | Q returns TRUE if CV is less than or equal to 0. |
Requirements
Development environment | Target platform | PLC library to include |
|---|---|---|
TwinCAT v3.0.0 | PC or CX (x86) | Tc2_Standard |