Allen-Bradley MicroLogix 1200 Reference Manual page 238

18-18 Using Interrupts
Publication 1762-RM001C-EN-P
EII Function File Sub-Elements
EII Program File Number (PFN)
Sub-Element Description
PFN - Program File Number
PFN (Program File Number) defines which subroutine is called (executed)
when the input terminal assigned to EII:0 detects a signal. A valid
subroutine file is any program file (3 to 255).
The subroutine file identified in the PFN variable is not a special file
within the controller. It is programmed and operated the same as any
other program file. From the control program perspective it is unique, in
that it is automatically scanned based on the configuration of the EII.
EII Error Code (ER)
Sub-Element Description Address
ER - Error Code
Any ER (Error Code) detected by the EII sub-system is displayed in this
register. The table below explains the error codes.
Table 18.13 EII Error Codes
Error Recoverable Fault
Code (Controller)
1 Invalid Program File
Number
2 Invalid Input
Selection
3 Input Selection
Overlap
EII User Interrupt Executing (UIX)
Sub-Element Description
UIX - User Interrupt Executing EII:0/UIX
The UIX (User Interrupt Executing) bit is set whenever the EII mechanism
detects a valid input and the controller is scanning the PFN. The EII
mechanism clears the UIX bit when the controller completes its
processing of the EII subroutine.
The EII UIX bit can be used in the control program as conditional logic to
detect if an EII interrupt is executing.
Address Data Format
EII:0.PFN word (INT)
Data Format
EII:0.ER word (INT)
Description
Program file number is less than 3, greater than 255, or does not
exist
Valid numbers must be 0, 1, 2, 3, 4, 5, 6, or 7.
EIIs cannot share inputs. Each EII must have a unique input.
Address Data Format
binary (bit)
Type User Program
Access
control read only
Type User Program
Access
status read only
Type User Program
Access
status read only