UPS Aviation Technologies Apollo SL70R, Installation Manual

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Serial Interface Specification
Apollo SL70R Installation Manual
34
7.4 I
NPUT
M
ESSAGES
The following messages are processed during normal operation. The AL and SW mes-
sages are also processed during setup and test modes.
Table 7-10. Normal Mode Input Messages
Msg ID Description Notes
#AL Altitude Message Must be selected in set up mode or it will be ignored.
#MD Set Mode Message Set mode A/C or STBY, IDENT and squawk code
#SW Request Software Version SL70R replies with Software Version Message
#RS Reset SL70R will reset after approximately 1 second.
#SO Set Operating Mode Setup or Test Modes
7.4.1
A
LTITUDE
The altitude-input function is intended to interface with serial altitude encoders. The alti-
tude source is selected during installation and must be set to Serial for this message to be
processed. Once selected the SL70R must receive a valid message at least once every 2
seconds or the altitude will time out and become invalid until the next valid message is
received.
7.4.1.1 I
NTERFACE
S
PECIFICATION
Buffer Length 17 bytes
7.4.1.2 A
LTITUDE
F
ORMAT
S
PECIFICATION
Table 7-11. Altitude Message Format
Byte Contents Description
0 ‘#’ ASCII ‘#’ (0x23)
1 ‘A’ ASCII ‘A’ (0x41)
2 ‘L’ ASCII ‘L’ (0x4C)
3 ‘ ‘ ASCII space (0x20)
4 ‘+’ or ‘-’ Altitude sign; ASCII ‘+’ or ‘-’ (0x2B or 0x2D)
5-9 ddddd Altitude in feet (right justified with zeros)
10 ‘T’ ASCII ‘T’ (0x54)
11 ‘+’ or ‘-’ Temperature sign; ASCII ‘+’ or ‘-’ (0x2B or 0x2D)
12-13 dd Internal Altimeter Temperature
14-15 dd Checksum of bytes 0 through 13. In hex ASCII i.e. “FA”
16 ‘\r’ ASCII carriage return (0x0D)
7.4.1.3 A
LTITUDE
F
ORMAT
S
PECIFICATION
E
XAMPLES
#AL +25D4 2100 feet above sea level (@29.92 inches Hg) with temperature
@+25
°
C
#AL -45DE 45 feet below sea level (@29.29 inches Hg) with temperature
@+45
°
C
#AL -09980T-12E6 ERROR CODE (temp below +25
°
C) with temperature @-12
°
C