R_TRIG: Recognize positive edge and trigger impulse
The R_TRIG (FB402) block recognizes the positive slope.
Functionality
For a positive slope of input [In], output [Out] is set to [Out] = 1 for the program cycle.
Inputs
Pin | E | Description |
In | pa | Input |
Outputs
Pin | E | Description |
Out | a | Output |
Input values
Pin | Description | Data Type | Default value | E.g. Engineering unit or Text group | Min. | Max. |
In | Input | Boolean | 0 (No) | No, Yes |
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Output values
Pin | Description | Data Type | Default value | E.g. Engineering unit or Text group | Min. | Max. |
Out | Output | Boolean | 0 (Off) | Off, On |
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Application
The R_TRIG block is used for various kinds of control tasks such as to recognize the initial use of a button.
Process response
Initialization before running the function:
- The old status of the input value is assumed to be [In] = No.
From the third cycle in the process, the block is processed with the value at the input, as it is only at this stage that the value at the input is considered to be valid. During the first two cycles in the process, the value at the output is the default value.
Note: During start-up, a continuous signal [In] = Yes at the input is identified as a leading edge. The corresponding pulse at the output [Out] = On occurs in the third cycle in the process.
Troubleshooting
Standard (see General rules and information).