Allen-Bradley MicroLogix 1200 Reference Manual page 235

STI User Interrupt Pending (UIP)
Sub-Element Description
UIP - User Interrupt Pending
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 execute immediately.
This bit is automatically set and cleared by the controller. The controller
can process 1 active and maintain up to 2 pending user interrupt
conditions before it sets the lost bit.
STI Timed Interrupt Enabled (TIE)
Sub-Element Description
TIE - Timed Interrupt Enabled
The TIE (Timed Interrupt Enabled) control bit is used to enable or disable
the timed interrupt mechanism. When set (1), timing is enabled, when
clear (0) timing is disabled. If this bit is cleared (disabled) while the timer
is running, the accumulated value is cleared (0). If the bit is then set (1),
timing starts.
This bit is controlled by the user program and retains its value through a
power cycle.
STI Auto Start (AS)
Sub-Element Description
AS - Auto Start
The AS (Auto Start) is a control bit that can be used in the control
program. The auto start bit is configured with the programming device
and stored as part of the user program. The auto start bit automatically
sets the STI Timed Interrupt Enable (TIE) bit when the controller enters
any executing mode.
Address Data Format Type
STI:0/UIP binary (bit)
Address Data Format Type
STI:0/TIE binary (bit)
Address Data Format Type
STI:0/AS binary (bit)
Using Interrupts 18-15
User Program
Access
status read only
User Program
Access
control read/write
User Program
Access
control read only
Publication 1762-RM001C-EN-P