RadioButtons and outputs

I have a screen that is based on section 4.6 of the release notes. I have put radio buttons in a group box as described in that section. Works OK. I have added action events to the buttons to turn on and off the output. This works OK. I have 2 problems. Verify using I/O Simulator.
1) When the screen is opened on the VFP the output is always set high. Even if it were set low before opening.

2) If the output is set low via the I/O simulator, it will remain low for only a fraction of a second and then be forced high by the screen. I have a program that pulses the output so that the output is set high for 1 second and low for 1 second. This works OK with the screen closed. If the screen is opened the the output only goes off for a fraction of a second.

Please, any comments on using radio button controlling an output.




  • Hello,

    There are 2 problems with the setup you have:


    1)  The buttons must have different "Checked" properties,  it is practical to set the "Checked" property of the On button to "True" and the Off button to "False".


    2)  There should not be any Events and actions associated with the buttons.  (It is these events that are causing part of the problem).   You currently have actions assigned to the "CheckedChar" event of both the radio buttons that reset the I/O signals.

     There are two ways to remove events, the first is to go to the Events Manager (Right-click on the radio button on the screen) and delete the events.  Then make sure that the "CheckedChar" event in the Events property page is empty (select the blank event).


    The second way is simply to delete the radio buttons and add new ones.
    Using Radio buttons is deceptively simple.   One button with Checked set to True, and bound to the digital output, the other button with Checked set to False.


    Kind Regards,





  • Hi,

    In this version of ScreenMaker, deleting a control will only delete the associated events which which are empty (no actions defined). If an event has at least one action, that event will not be deleted; it must be deleted by hand by using the Events Manager Form (available in the context menu after a right click in the Screen).


    Carlos Martinez