SYSTEM INSTALLATION MANUAL
89000016
Figure 3075. (Sheet 1 of 1) Check Ground on UAT Antenna Display
6.
KGX Control Panel Test and Calibration
A.
Local Voltage Supply Test
(1)
The KGX control panel utilizes a DC supply voltage of 5.5 to 8 volts. The display typically
shows the supply voltage between 6.5 to 7.1 volts as shown in Figure 3076.
Figure 3076. (Sheet 1 of 1) Local Voltage Supply Test Display
(2)
There is no option or configuration to be entered or selected in this step. Press the ENT key or
the FN key and move to the next configuration item in the configuration mode.
B.
KGX Control Panel Altitude Encoder Calibration
(1)
General
(a)
The KGX control panel includes a built-in altitude encoder. The KGX control panel reports
pressure altitude on Pin 4 of the DB-9 male connector on the back of the KGX control
panel as RS-232 serial data, at 9600 bps, using the format commonly called “Icarus”
format. SERIAL INTERFACE SPECIFICATIONS, Paragraph 2, provides further details of
interfacing the altitude encoder with the primary static pressure of the aircraft altimeter.
(b)
The calibrate altitude encoder setup allows the recalibration of the altitude encoder. This
ensures that the altitude seen on the pilot’s primary altimeter is the same as what is
transmitted by the KGX. The maximum allowed difference between the primary altimeter
and the altitude encoder is 125 feet (38.1 m) in ETSO C88a and TSO C88b.
(c)
The altitude encoder in the KGX control panel is accurately calibrated in the factory to
be within 50 feet (15.3 m) of the applied pressure altitude at all altitudes, whereas the
allowed error in the primary altimeter increases with altitude, and above 18,000 feet (3.41
mile) the altimeter error alone can exceed 125 feet (38.1 m).
(d)
It is therefore possible that the combination of the allowed errors in the encoder and the
primary altimeter can exceed 125 feet (38.1 m), in which case the altitude encoder must
be adjusted to correspond to the primary altimeter.
NOTE:
The purpose of calibrating the encoder is to make the output correspond to
the primary altimeter. The encoder calibration procedure must therefore only
be undertaken after the primary altimeter has been tested and found to
comply with the relevant standards.
(2)
Calibration Equipment
(a)
To calibrate the encoder, the KGX control panel must be powered up and you will need
a pitot-static test set with the appropriate adapters to connect to the static port on the
EFFECTIVITY
ALL
Page 3056
22 Dec 2016
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