Back to FBD referenceTypical FBD symbol for TP
Timers
TP
Pulse timer
The TP block starts a pulse on the rising edge of IN. While the pulse is active, Q remains TRUE for the configured duration.
Typical FBD symbol
IN
TP
Q
Inputs
| Name | Type | Required | Description |
|---|---|---|---|
| IN | BOOL | Yes | Pulse start signal on the rising edge. |
Outputs
| Name | Type | Required | Description |
|---|---|---|---|
| Q | BOOL | Yes | Pulse timer output. |
Parameters
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
| PT_SCANS | number | No | 1 | Pulse duration in scans. |
| PT | number | No | - | Pulse duration in milliseconds when a time preset is used. |
Stateful
Yes, the block keeps internal state between scans.
Behavior rule
On the rising edge of IN, emits Q = TRUE for the configured number of scans or time.
Scan table
Example for PT_SCANS = 2.
| Scan | IN | event | Q |
|---|---|---|---|
| 1 | FALSE | - | FALSE |
| 2 | TRUE | front | TRUE |
| 3 | TRUE | pulse | TRUE |
| 4 | TRUE | elapsed | FALSE |
Practical use
- short control pulse;
- starting a one-shot action.
What to watch
- Expecting a constant output while IN is held TRUE. TP starts from an edge.