CTUD
The function block CTUD is an up and down counter.
Inputs
VAR_INPUT
CU : BOOL; (* Count Up *)
CD : BOOL; (* Count Down *)
RESET : BOOL; (* Reset Counter to Null *)
LOAD : BOOL; (* Load Start Value *)
PV : WORD; (* Start Value / Counter Limit *)
END_VARName | Type | Description |
|---|---|---|
CU | BOOL | Counting up |
CD | BOOL | Counting down |
RESET | BOOL | Reset the counter to 0. |
LOAD | BOOL | Load start value. |
PV | WORD | Start value/counter limit |
Outputs
VAR_OUTPUT
QU : BOOL; (* Counter reached Limit *)
QD : BOOL; (* Counter reached Null *)
CV : WORD; (* Current Counter Value *)
END_VARName | Type | Description |
|---|---|---|
QU | BOOL | QU returns TRUE if CV has become greater than or equal to PV. |
QD | BOOL | QD returns TRUE if CV has become less than or equal to 0. |
CV | WORD | If RESET applies, the count variable CV is initialized with 0. If LOAD applies, CV is initialized with PV. If CU has a rising edge from FALSE to TRUE, then CV is increased by 1 as long as CV does not cause an overflow. If CD has a rising edge from FALSE to TRUE, then CV is decremented by 1 as long as CV does not cause an underflow. |
Requirements
Development environment | Target platform | PLC library to include |
|---|---|---|
TwinCAT v3.0.0 | PC or CX (x86) | Tc2_Standard |