GTX 33 Installation Manual 190-00906-00
Page 1-4 Rev. F
1.6 Interface Summary
The GTX 33 provides the following interface connections via the rear connector. See Section 4 and
Appendix D for connection details.
• Ten (10) encoding altimeter inputs
• External IDENT input
• External STBY input (useful for dual transponder installations)
• External suppression pulse input
• Switched power output of up to 1.5 amps (for digital altitude encoder power)
• Aircraft power input (14/28 Vdc)
• Remote power turn on
• Serial airdata or GPS groundspeed input
• Serial altitude input (Reduces wire count vs. parallel wire gray code altimeter interface.)
• Software update input
• Supports Comm-A and Comm-B protocol
• Temperature, Altitude Hold and Density Altitude
• Digitally recorded voice and discrete warning annunciator activated by Altitude Hold when limits
are exceeded
• Diversity: GTX 33D is available with the diversity feature
• ARINC 429 input
The GTX 33 P/N 010-00267-() and GTX 33D 010-00294-() support the following list of Comm-B
Definition Subfield (BDS) registers:
• BDS (0,0) Air Initiated Comm-B (AICB).
• BDS (1,0) Data Link Capability Report.
• BDS (1,7) Common Usage Ground Initiated Comm-B (GICB) Capability Report.
• BDS (1,8) Mode S Specific Services GICB Capability Report.
• BDS (1,9) Mode S Specific Services GICB Capability Report.
• BDS (1,D) Mode S Specific Services Protocols (MSP) Capability Report.
• BDS (2,0) Aircraft Identification.
• BDS (4,0) Selected Vertical Intention
• BDS (5,0) Track and Turn Report
• BDS (6,0) Heading and Speed Report
• BDS (0,6) Extended Squitter surface Position
• BDS (0,5) Extended Squitter Airborne Position
• BDS (0,8) Extended Squitter Aircraft Identification and Category
• BDS (0,9) Extended Squitter Airborne Velocity – Subtypes 1 and 3
• BDS (0,A) Extended Squitter Event Driven Data
• BDS (6,1) Emergency/Priority Status
• BDS (6,5) Aircraft operational Status