Falling Edge (One-Shot) Contact - LDF
Connection Requirements
Supported PLC Series
| XPnA/1R | XPnB | XPnE | XPnF | CP3A/B/P/U CP4A~D/U | CPnE | CPnF | BP | PLC-S |
|---|---|---|---|---|---|---|---|---|
| ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
Supported Data Registers
| M | X | Y | K | L | F | T | C | S | Z | R | Q | D | @D | Constant | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| S | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - | - | ✓ | ✓ | - | - |
Supported Flags
| Flag | Bit | Support |
|---|---|---|
| Error | F11.0 | - |
| Zero | F11.1 | - |
| Carry | F11.2 | - |
Number of Steps
| Steps |
|---|
| 1 |
Operands
| Operand | Description |
|---|---|
| S | This is the BOOL data register. This is the bit number to toggle the contact ON/OFF. When the bit is 0, the contact is OFF. When the bit is 1, the contact is ON. |
Notice
Contact Orientation
The LDF falling edge (one-shot) contact orientation behaves as follows:
- The LDF falling edge (one-shot) contact orientation is ON for 1 scan only.
- The one-shot contact is ON at the falling edge of the assigned BOOL data register.
- The one-shot contact turns ON when the assigned BOOL data register goes from OFF to ON.
tip
The one-shot contact turns ON on the falling edge of an input signal or condition.