Configuring Timed Interrupts; Interrupt Block Scheduling - GE PACSystems RXi User Manual

Note:
6.3.2

Configuring Timed Interrupts

A block can be configured to execute on a specified time interval with an initial delay (if
specified) applied on a Stop-to-Run transition of the CPU.
To configure a timed interrupt block, specify the following parameters in the scheduling
properties for the block:
Time Base
Interval
Delay
The first execution of a Timed Interrupt block will occur at
((delay  time base) + (interval  time base)) after the CPU is placed in Run mode.
6.3.3

Interrupt Block Scheduling

You can select one of two types of interrupt block scheduling at the target level:
■
Normal block scheduling allows you to associate a maximum of 16 Timed Interrupts.
With normal block scheduling, all interrupt-triggered blocks have equal priority. This is the
default scheduling mode.
■
Preemptive block scheduling allows you to associate a maximum of 32 interrupt
triggers. With preemptive block scheduling, each trigger can be assigned a relative
priority.
Normal Block Scheduling
Interrupt-driven logic has the highest priority of any user logic in the system. The execution of
a block triggered from an interrupt preempts the execution of the normal CPU sweep
GFK-2816F
We strongly recommend that interrupt-driven blocks not be called from the _MAIN
block or other non-interrupt driven blocks because the interrupt and non-interrupt
driven blocks could be reading and writing the same global memories at
indeterminate times relative to each other. In the example below INT1, INT2,
BLOCK5, and PB1 should not be called from _MAIN, BLOCK2, BLOCK3,
or BLOCK4.
_MAIN
Block
The smallest unit of time that you can specify for Interval and Delay. The time base
can be 1.0 second, 0.10 second, or 0.01 second, or 0.001 second.
Specifies how frequently the block executes in multiples of the time base.
(Optional) Specifies an additional delay for the first execution of the block in multiples
of the time base.
INT Block 1
INT Block 2
Block
2
Block
3
Block
4
August 2015
Chapter 6. Program Organization
Block
5
PB
1
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