II Morrow Inc. NMC 2001 Operating Manual page 70

Message Displays Operations
Low Battery Voltage - Keypad
The low battery voltage message is generated when the NMC detects a
low battery voltage in the keypad. The unit must be serviced within
about a month after the first time this warning is seen. It becomes an
old message after being viewed.
High Battery Voltage
The high battery voltage message is generated when the NMC detects
a high battery voltage. The unit must be returned for service.
Continued operation is not recommended. It becomes an old message
after being viewed.
Countdown Timer Expired Message
The display below shows the active countdown timer has expired. The
countdown timer is set in NAV mode. The message is cleared when the
user views the message (it does not become an old message) or
reactivates the Countdown Timer.
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