190-01115-01 G3X™/G3X Touch™ Avionics Installation Manual
Rev. AV Page C-8
C.7 EIS Complete Data Message Format
The EIS Complete Data Message outputs all Engine/Airframe Information System (EIS) data available to
the G3X™ avionics system. Because the amount of EIS data available to the G3X system depends on the
aircraft’s specific configuration, EIS messages use a flexible format that is expandable and self-describing.
EIS messages are identified by sub-type and contain a variable number of fixed-width fields, each of which
contains data for a specific EIS parameter. These messages support up to 256 EIS parameters, each of
which is identified by a numeric parameter ID. Each item of EIS data is transmitted at a periodic rate, or
when its value changes. The maximum length of any EIS message, including checksum and leading/
trailing characters, will not exceed 256 bytes.
C.7.1 EIS Parameter Information
The Parameter Information message sub-type is transmitted periodically to allow receiving devices to
decode the other EIS message sub-types. It contains a variable number of fixed-width parameter
description records, each of which identifies the name and units of measurement associated with a single
parameter ID. Transmitting details for all configured parameters may involve multiple Parameter
Information messages.
NOTE
Parameter name strings will be null-terminated only if their length is less than the
maximum of 16 characters.
Table C-6 EIS Parameter Information Message
Field Name Offset Width Units Notes
Escape character 0 1 ‘=’
Sentence ID 1 1 ‘5’
Sentence version 2 1 Currently ‘1’
Sentence sub-ID 3 1 ‘i’ (ASCII 0x69)
Parameter ID 12 2 ASCII hex
Parameter Units 14 1 See Table C-5
Parameter Name 15 16 ASCII string
…variable number of records…
Parameter ID 2 ASCII hex
Parameter Units 1 See Table C-5
Parameter Name 16 ASCII string
Checksum End-4 2 ASCII hex 8-bit sum of all previous bytes
CR/LF End-2 2 0x0D / 0x0A
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