Table of Contents
Advertisement
Service Alarm
NOTE
The service alarm provides an alarm that alerts you of possible system
problems that require attention.
Events that can trigger the service alarm are:
•
Error condition (detected by software)
•
System operational variance (such as an over-temperature or under-
temperature condition)
•
Calibration failure
•
Verification failure
•
Control unit power failure
Watchdog Relay
NOTE
The watchdog alarm relay de-energizes when the system watchdog timer
times out. The watchdog timer will time out and cause the control unit to
reset itself to prevent the control unit from becoming "lost" due to such
things as noise spikes or power surges. You can use this relay to activate a
remote indicator to notify you if the watchdog timer times out.
In addition, the control unit reads the watchdog after reset, and beeps for
a brief time if the reset was caused by a watchdog condition. Pressing the
reset keys simultaneously (hidden keys to the left and right of the Setup
Key) for a long enough time will in turn cause a watchdog, which will
indicate as a beep after the system restarts upon release of the reset keys.
Exception Log
The exception log provides a history of the following types of events:
•
System or error messages
•
Alarm conditions
•
Reset conditions
•
Start of calibrations or verifications
The service alarm operates as normally closed (service alarm condi-
tion causes open contacts).
During normal system operation, the watchdog relay operates as
normally closed (system failure causes open contacts).
Controller / User Interface
|
4-23
Advertisement
Table of Contents
