Avidyne Envision EX5000 - MFD CMOS Battery Operation and Replacement; CMOS Battery; Operating Without a CMOS Battery

MFD CMOS Battery Operation and Replacement
600-00151-001 Rev 01 -77- Envision EX5000
7.5 MFD CMOS Battery Operation and
Replacement
7.5.1 CMOS Battery
A CMOS (Complementary Metal-Oxide Semiconductor) battery is
used in the EX5000 Series of MFDs to maintain the system clock. On
average, CMOS batteries have been shown to last over 10 years.
The clock in the EX5000 Series of MFDs is used to display the
current time to the operator and to determine, among other things, the
age of datalink products. Additionally, this clock is also used to tag
logged data and in calculations such as ETA. Replacement of a
CMOS battery is optional. The following section describes the steps
that are needed to operate an EX5000 Series MFD with a
nonfunctioning CMOS battery
7.5.2 Operating without a CMOS Battery
This section specifies the recommended steps that should be taken if/
when the CMOS battery is no longer capable of maintaining the
system time in an EX5000 Series MFD.
Without a CMOS battery, the system will report the current year to be
2000. If this is the case, the system setting should be checked to
make sure the "manual" mode of clock update is not enabled. Follow
the prescribed steps in the "System Time Page" section of the
EX5000 Pilot Guide to set the system to either the "Auto" or "GPS"
selection (either selection will update the MFD with the appropriate
time). No other actions are required in order to update the system
time.
When the system time selection is set to "Auto" or "GPS", the MFD
will automatically correct the system time using the incoming GPS
data once it is available. All Cirrus, Piper and Lancair OEM
configurations, which include the EX5000, are attached to a GPS
(GNS430 or IFD440/IFD540) and hence will automatically correct the
system time upon battery failure if configured to default to GPS time.
Until the GPS time is acquired by the connected GPS, the EX5000
Series of MFDs will display an incorrect time. The connected GPS
system typically takes 45 seconds or less to acquire GPS time
following system startup. Since the GPS position (and thus time) is
available prior to takeoff the time will always be correct prior to
takeoff.