A CALL PROCESS (process) can be used to update the interprocess variables located on a form displayed from another process. In addition, if the On Outside Call event in the Form Properties is enabled and a process reference number is set in the process parameter, the form displayed in the target process receives an On Outside call event. This event must be enabled for that form in the Design environment Form Properties window, and you must manage the event in the form method. If the event is not enabled or if it is not managed in the form method, nothing happens. If you pass -1 instead of a process reference number in the process parameter, 4th Dimension does not call any process or trigger an On Outside Call event. Instead, it redraws all the interprocess variables currently displayed in all windows of any process running on the same machine.
Note: CALL PROCESS only works between processes running on the same machine.