R_EDGE (Attribute)

R_EDGE is an attribute that can be used on the BOOL variables that are declared in a VAR_INPUT section. By using this attribute, the variable it is used on will only be TRUE when there is a rising edge detected on the input value.

Please also have a look at F_EDGE for a falling edge attribute.

All variables with the R_EDGE attribute will only be updated when BEGIN or UPDATEIO() is executed.

Example:

For an example of the R_EDGE, please have a look at the CTD function block.