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Chapter 14 : fail-safe system, Overview, Chapter 14: fail-safe system – Horner APG QX751 OCS User Manual

Page 73

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MAN0890-02-EN

CH. 14

August 20, 2009

Page 73 of 96

ECN # 979

CHAPTER 14: FAIL-SAFE SYSTEM


14.1 Overview

The Fail-Safe System is a set of features that allow an application to continue running in the event of
certain types of "soft" failures. These "soft" failures include:

• Battery power loss

• Battery-Backed Register RAM or Application Flash corruption due to, for example, an excessive

EMI event.

The Fail-Safe System has the following capabilities:

• Manually backup the current Battery-Backed RAM Register Settings into Flash memory.

• Manually restore Register Settings from the values previously backed up in Flash to Battery-

Backed RAM.

• Detect corrupted Register Settings at power-up and then automatically restore them from Flash.

• Detect corrupted or empty application in Flash memory at power-up and then automatically load

the AUTOLOAD.PGM application file from Removable Media (Compact Flash or MicroSD).

If an automatic Register Restore or Application Load occurs, the OCS can automatically be
placed in RUN mode


The fail-safe system can be accessed by going to the system menu of the controller. The menu “Fail-Safe
System” has been added at the end of the main system menu for this. Selecting “Fail-Safe System” menu
will open the following menu screen:

Figure 14.1 – Fail-Safe System