Figure 14: Cpu Sweep In Stop-I/O Disabled And Stop-I/O Enabled Modes - Emerson PACSystems RX3i User Manual

PACSystems™ RX3i and RSTi-EP CPU Reference Manual
GFK-2222AK
4.5.1.2 STOP-I/O Disabled Mode
I/O Scan Disabled - the Input and Output scans are skipped.
When the CPU is in STOP Mode, it does not execute the application program. You can
configure whether the I/O is scanned during STOP Mode. Communications with the
programmer and intelligent option modules continue in STOP Mode. Also, bus receiver
module polling and rack reconfiguration continue in STOP Mode.
In both STOP Modes, the Controller Communications and Backplane Communications
windows run in Run-to-Completion mode and the Background window runs in Limited
mode with a 10 ms limit.
The number of last scans can be configured in the hardware configuration. Last scans are
completed after the CPU has received an indication that a transition from Run to Stop or
Stop Faulted mode should occur. The default is 0.
SVCREQ13 can be used in the application program to stop the CPU after a specified
number of scans. All I/O will go to their configured default states, and a diagnostic
message will be placed in the CPU Fault Table.

Figure 14: CPU Sweep in Stop-I/O Disabled and Stop-I/O Enabled Modes

CPU Operation
Start-of-Sweep
Housekeeping
Input Scan
Output Scan
Controller
Communications
Window
Backplane
Communications
Window
Background Task
Window
Executes in
Stop-I/O Scan Enabled
mode only
Executes in
Stop-I/O Scan Enabled
mode only
Runs
to
completion
Runs
to
Completion
Limited
(10ms)
Section 4
October 2019
89