Why does the ComboBox overwrite my string?

DavidR

Hi everyone!

I have an issue when a ComboBox and the RAPID program writes to the same PERS string.

Let's say a string called sStationStatus has been assigned by the RAPID program, sStationStatus:="Station empty". When the the app (created in ScreenMaker) is opened the string sometimes will go back to "".

Is it suppose to be this way?

Bigger problem on a real controller than in a virtual one. RobotWare 6.03.02.

/David

DavidR

This seems to be a known issue. I got this answer from ABB robotics support:

"The combobox behavior is due to Windows Compact Framework event handling design. Which works fine when data bindings are local, but which introduces a lot of issues when the Value property has a Binding to a Controller value.

When the Screen loses focus no events are generated which means the value binding doesn't update properly, and then when the Screen gains focus it triggers Change events on the combobox, pushing down the same value to the controller.

The workaround solution is to avoid Value property Binding, and instead use Buttons to trigger Refresh and Write from/to the controller.

From a Usability perspective this is not ideal, but it avoids the Focus / Event issues completely."

I did what they recommended and created application variables for each RAPID data and transferred data between them with two buttons for read and write. The ComboBox then used the application variable for "Selected value", the "items" was still a RAPID array.

/David