CTD ( Down Counter )
| Function name | CTD_010 |
|---|---|
| Function version | 1.0 |
| Function state | stable |
| Compatibility with IEC61131-3 | compatible |
Graphic symbol :
Input / Output :
| Name | Belonging Group | Access | Types of data | Description |
|---|---|---|---|---|
| EN | Left Power Flow | IEC1131-3 enable input | ||
| CD | Normal | R , RW | F , B , W , L , S | Decrease counter on the raising front |
| LD | Normal | R , RW | F , B , W , L , S | Loading counter |
| PV | Normal | R , RW | B , W , L , S | Preset counter |
| Q | Normal | W , RW | F , B , W , L , S | Counter state |
| CV | Normal | W , RW | B , W , L , S | Present value of the counter |
| ENO | Right Power Flow | IEC1131-3 enable output |
Description :
The counter block Down Counter counts backward from the current value preset on the raising front of the count down input (CD). When the current value (CV) is equal to zero, the output bit of the counter (Q) is activated. The counter resets the current value (CV) with the preset value (PV) when the loading counter (LD) is active and stops counting when it reaches the zero.