Allen-Bradley MicroLogix 1200 Reference Manual page 79

User Interrupt Pending (UIP)
Description Address Data Format
UIP - User HSC:0/UIP bit
Interrupt
Pending
(1) For Mode descriptions, see HSC Mode (MOD) on page 5-16.
The UIP (User Interrupt Pending) is a status flag that represents an
interrupt is pending. This status bit can be monitored or used for logic
purposes in the control program if you need to determine when a
subroutine cannot be executed immediately.
This bit is maintained by the controller and is set and cleared
automatically.
User Interrupt Lost (UIL)
Description Address Data Format HSC Modes
UIL - User HSC:0/UIL bit
Interrupt Lost
(1) For Mode descriptions, see HSC Mode (MOD) on page 5-16.
The UIL (User Interrupt Lost) is a status flag that represents an interrupt
has been lost. The controller can process 1 active and maintain up to 2
pending user interrupt conditions.
This bit is set by the controller. It is up to the control program to utilize,
track if necessary, and clear the lost condition.
Low Preset Mask (LPM)
Description Address
LPM - Low HSC:0/LPM bit
Preset Mask
(1) For Mode descriptions, see HSC Mode (MOD) on page 5-16.
The LPM (Low Preset Mask) control bit is used to enable (allow) or
disable (not allow) a low preset interrupt from occurring. If this bit is clear
(0), and a Low Preset Reached condition is detected by the HSC, the HSC
user interrupt is not executed.
This bit is controlled by the user program and retains its value through a
power cycle. It is up to the user program to set and clear this bit.
(1)
HSC Modes
0 to 7
(1)
0 to 7
Data Format HSC Modes
2 to 7
Using the High-Speed Counter
Type User Program Access
status read only
Type User Program Access
status read/write
(1) Type User Program Access
control read/write
Publication 1762-RM001C-EN-P
5-9