Cpu Stop Modes; Figure 44: Cpu Sweep In Stop-I/O Disabled And Stop-I/O Enabled Modes - GE PACSystems RX7i Reference Manual

Chapter 4. CPU Operation

4.5.1 CPU STOP Modes

The CPU has four modes of operation while it is in STOP Mode. The two most common are:
STOP-I/O Enabled Mode
▪
I/O Scan Enabled - the Input and Output scans are performed each sweep.
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 44: CPU Sweep in Stop-I/O Disabled and Stop-I/O Enabled Modes

150
Start-of-Sweep
Housekeeping
Input Scan
Output Scan
Controller
Communications
Window
Backplane
Communications
Window
Background Task
Window
PACSystems* RX7i, RX3i and RSTi-EP CPU Reference Manual
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)
GFK-2222AD