Chapter 6. Service Request Function280 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C6.3 SVC_REQ 2: Read Window Modes and Time ValuesUse SVC_REQ 2 to obtain the current window mode and time values for the controllercommunications window and the backplane communications and the background task window.The parameter block has a length of three words. All parameters are output parameters. It is notnecessary to enter values in the parameter block to program this function.OutputAddress Window High Byte Low ByteAddress Controller Communications Window Mode Value in msAddress + 1 Backplane Communications Window Mode Value in msAddress + 2 Background Window Mode Value in msNote: A window is disabled when the time value is zero.Mode ValuesMode Name Value DescriptionLimited Mode 0 The execution time of the window is limited to its respective default valueor to a value defined using SVC_REQ 3 for the controller communicationswindow or SVC_REQ 4 for the systems communications window. Thewindow will terminate when it has no more tasks to complete.Constant Mode 1 Each window will operate in a Run to Completion mode, and the CPU willalternate among the three windows for a time equal to the sum of eachwindow's respective time value. If one window is placed in Constant mode,the remaining two windows are automatically placed in Constant mode. Ifthe CPU is operating in Constant Window mode and a particular window'sexecution time is not defined using the associated SVC_REQ function, thedefault time for that window is used in the constant window timecalculation.Run to CompletionMode2 Regardless of the window time associated with a particular window,whether default or defined using a service request function, the window willrun until all tasks within that window are completed.SVC_REQ 2 ExampleWhen %Q00102 is set, the CPU places the current time values of thewindows in the parameter block starting at location %R0010.
