How Enter key handshaking works at runtime
When an object’s
Enter
button is pressed, the object writes a value to the data source. Use Enter
key handshaking to hold the value at the data source for a specific period of time to ensure it is read before the object overwrites the value.You can use
Enter
key handshaking with these objects:- String input enable button
- Control list selector
- Numeric input enable button
- Numeric input cursor point
Use objects in the graphic display
- Before the Enter connection is reset to 0, the operator can provide input to other objects in the graphic display.
- If the operator presses theEnterkey (using a key button or external keyboard or keypad) for an object whose Enter connection has not yet been reset , the application logs an error.
Graphic display changes
If the graphic display is closed, the Enter connection is reset to 0 and any handshake timing is also reset. In effect, the handshaking is canceled.
To set up an object for handshaking
Enter key handshaking works by setting the object's Enter connection to 1. Until the Enter connection is reset to 0, no new values can be sent to the Value connection.
There are two ways of using
Ente
r key handshaking:- Hold the value at the data source for a specified period of time,
- Hold the value at the data source until the data source notifies FactoryTalk View that the value has been read.
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