1766-RM001A-EN-P MicroLogix 1400 Programmable Controllers ...

Using Interrupts 319Selectable Time Interrupt (STI) Function File Sub-Elements SummarySelectable Timed Interrupt Function File (STI:0)Sub-Element Description Address Data Format Type User ProgramAccessPFN - Program File Number STI:0.PFN word (INT) control read only 319ER - Error Code STI:0.ER word (INT) status read only 319UIX - User Interrupt Executing STI:0/UIX binary (bit) status read only 320UIE - User Interrupt Enable STI:0/UIE binary (bit) control read/write 320UIL - User Interrupt Lost STI:0/UIL binary (bit) status read/write 320UIP - User Interrupt Pending STI:0/UIP binary (bit) status read only 321TIE - Timed Interrupt Enabled STI:0/TIE binary (bit) control read/write 321AS - Auto Start STI:0/AS binary (bit) control read only 321ED - Error Detected STI:0/ED binary (bit) status read only 322SPM - Set Point Msec STI:0.SPM word (INT) control read/write 322For MoreInformationSTI Function File Sub-ElementsSTI Program File Number (PFN)Sub-Element Description Address Data Format Type User ProgramAccessPFN - Program File Number STI:0.PFN word (INT) control read onlyThe PFN (Program File Number) variable defines which subroutine iscalled (executed) when the timed interrupt times out. A valid subroutinefile is any program file (3…255).The subroutine file identified in the PFN variable is not a special filewithin the controller; it is programmed and operates the same as anyother program file. From the control program perspective it is unique, inthat it is automatically scanned based on the STI set point.STI Error Code (ER)Sub-Element Description Address Data Format Type User ProgramAccessER - Error Code STI:0.ER word (INT) status read onlyError codes detected by the STI sub-system are displayed in this register.The table below explains the error codes.Publication 1766-RM001A-EN-P - October 2008