Mid-Continent Instrument MD41-1510 Technical Document

INSTALLATION MANUAL AND
OPERATING INSTRUCTIONS
MD41-151X Series
GPS Annunciation Control Unit
For Garmin GTN 6XX/7XX Systems
MD41-1510 28vdc Horizontal Mount
MD41-1512 14vdc Horizontal Mount
MD41-1514 28vdc Horizontal Mount, 5vdc lighting
MD41-1511 28vdc Vertical Mount
MD41-1513 14vdc Vertical Mount
MD41-1515 28vdc Vertical Mount, 5vdc lighting
REV. A February 21, 2011 MANUAL NUMBER 9017211
MID-CONTINENT INSTRUMENT CO., INC.
9400 E. 34
th
Street N., Wichita, KS 67226 USA
phone [phone] •fax [phone] •web www.mcico.com

REV. A February 21, 2011 3 Manual Number 9017211
REVISION DETAIL
Rev. Date Detail
A 02/21/11 Initial release.

REV. A February 21, 2011 4 Manual Number 9017211
TABLE OF CONTENTS
SECTION 1 GENERAL DESCRIPTION
1.1 INTRODUCTION
1.2 TECHNICAL SPECIFICATIONS
1.2.1 MODELS
1.2.2 PHYSICAL ATTRIBUTES
1.2.3 PERFORMANCE
SECTION 2 INSTALLATION CONSIDERATIONS
2.1 COOLING
2.2 EQUIPMENT LOCATION
2.3 ROUTING OF CABLES
2.4 LIMITATIONS
SECTION 3 INSTALLATION PROCEDURE
3.1 GENERAL INFORMATION
3.2 UNPACKING AND INSPECTING
3.3 CABLE HARNESS
3.3.1 LIGHTING CONTROLS
3.3.2 SIGNALS AND POWER
3.3.3 HARNESS VERIFICATION
3.4 MOUNTING
SECTION 4 OPERATION
4.1 FRONT PANEL CONTROLS AND ANNUNCIATIONS
4.1.1 CONTROLS
4.1.2 ANNUCIATIONS
SECTION 5 CONFORMANCE
5.1 OPERATING INSTRUCTIONS
5.2 CONTINUED AIRWORTHINESS STATEMENT
5.3 ENVIRONMENTAL QUALIFICATION STATEMENT
NUMBER LIST OF TABLES AND FIGURES
1.1 MODELS TABLE
1.2 PHYSICAL ATTRIBUTES TABLE
1.3 PERFORMANCE TABLE
3.3 CONNECTOR PINOUT FIGURE
3.3 SCHEMATIC PIONOUT TABLE
3.4 OUTLINE DRAWING
3.5 WIRING DIAGRAM
4.1 FRONT PANEL FIGURE

REV. A February 21, 2011 5 Manual Number 9017211
SECTION 1 GENERAL DESCRIPTION
1.1 INTRODUCTION
The MD41-151X series products are compact, self-contained Annunciation and Control Units (ACUs). The
fully integrated control unit provides annunciation and mode selection for Global Positioning System
(GPS) / Satellite-Based Augmentation System (SBAS) navigators. This series of the MD41 product family
is specifically designed to work with the Garmin GTN 6XX/7XX series WAAS navigator systems and
derivatives with equivalent functionality. It combines the necessary functions and annunciations required
to interface with an approved system and provide regulatory compliance with GPS/SBAS minimum
performance specifications.
Highlighted features include long-life LEDs used for all lighting, internally backlit selection switches, dead-
front inactive annunciations, and the installation option for manual or automatic dimming. An external
annunciation dimming adjustment is provided for balancing low-level light conditions.
1.2 TECHNICAL SPECIFICATIONS
1.2.1 MODELS
Unit Configurations
MD41-1510 MD41-1512 MD41-1514
Orientation Horizontal Horizontal Horizontal
Power Input 28VDC 14VDC 28VDC
Lighting Input 28VDC 14VDC 5VDC
MD41-1511 MD41-1513 MD41-1515
Orientation Vertical Vertical Vertical
Power Input 28VDC 14VDC 28VDC
Lighting Input 28VDC 14VDC 5VDC
Table 1.1
1.2.2 PHYSICAL ATTRIBUTES
Characteristics:
Weight: 0.26 pounds
Dimensions:
(not including connector or mate) 3.2 inches long 3.25 inches wide
0.8 inches high
Mating Connector: Positronic RD25F10JVL0 or equivalent (MCI P/N 7014517)
Instrument Panel Mounting: Rear mount
Table 1.2
1.2.3 PERFORMANCE
Specifications:
Qualification: FAA TSO-C129
Environmental Qualification: RTCA DO-160D Environmental Category
F2CAB(SM/UG)XXXXXXZBABA(TT)M[A3C3]XXA*
* Sections 16, 20, 21, and 22 comply with DO-160C, Section 8
(UG) complies with DO-160F
Power Requirement: 0.20 A max

REV. A February 21, 2011 6 Manual Number 9017211
Table 1.3
SECTION 2 PRE-INSTALLATION CONSIDERATIONS
2.1 COOLING
No direct cooling is required. As with any electronic equipment, overall reliability may be increased if the
unit is not located near a high heat source or crowded next to other equipment. Means of providing some
airflow would be considered beneficial.
2.2 EQUIPMENT LOCATION
The MD41-151X series ACU must be mounted as close to the pilot’s field of view as possible. Please
reference the GPS/SBAS installation manual for approved locations. The unit depth, with connector
attached, must also be taken into consideration when selecting an appropriate location. Allow at least 3
inches of space behind the unit for connector attachment and removal.
2.3 ROUTING OF CABLES
Care must be taken not to bundle the MD41 series ACU logic and low level signal lines with any high
energy sources. Examples of these sources include 400 HZ AC, Comm, DME, HF and transponder
transmitter coaxial cables. Always use shielded wire when shown on the installation print.
Avoid sharp bends in cabling and routing near aircraft control cables. Also avoid proximity and contact
with aircraft structures, avionics equipment, or other obstructions that could chafe wires during flight and
cause undesirable effects.
2.4 LIMITATIONS
The conditions and tests for TSO approval of this article are minimum performance standards. Those
installing this article, on or in a specific type or class of aircraft, must determine that the aircraft
installation conditions are within the TSO standards. TSO articles must have separate approval for
installation in an aircraft. The article may be installed only according to 14 CFR part 43 or the applicable
airworthiness requirements.
Note that this product is part of an incomplete system. It is designed to be installed with other applicable
equipment to provide functionality for global positioning /satellite-based augmentation systems.

REV. A February 21, 2011 7 Manual Number 9017211
SECTION 3 INSTALLATION PROCEDURES
3.1 GENERAL INFORMATION
This section contains interconnect diagrams, mounting dimensions and other information pertaining to
the installation of the MD41 series ACU. After installation of cabling and before installation of the
equipment, ensure that power is applied only to the pins specified in the interconnect diagram.
3.2 UNPACKING AND INSPECTING EQUIPMENT
When unpacking this equipment, make a visual inspection for evidence of any damage that may have
incurred during shipment. The following parts should be included:
a. GPS ACU – MCI P/N MD41-151X series
b. J1 Connector Kit (25 pin) – MCI P/N 7014517
c. Installation Manual – MCI P/N 9017211
3.3 CABLE HARNESS
The MD41 cable harness should be made using 24 AWG wire or larger for all connections. Construct the
cable harness with regards to the instructions below and using the Connector Pinout of Figure 3.3,
Schematic Pinout of Table 3.3, and Wiring Diagram of Figure 3.5.
Refer to Section 2: Pre-Installation Considerations in regards to routing precautions.
3.3.1 LIGHTING CONTROL
Button backlighting (pin 5) is powered (5vdc, 14vdc, or 28vdc) from the aircraft’s panel
lighting bus. This will allow manual dimming control of the button brightness using the
aircraft’s panel lighting control dimmer.
There are three options for annunciation brightness control. The annunciations options can
be configured in the following ways:
•Full bright when active
oconnect aircraft power (same as pin 13 input) to pin 6
•Manual control using the aircraft’s panel lighting control
oconnect the aircraft lighting bus power output (same as pin 5 input) to pin 6
o(not available for aircraft with 5V lighting bus)
•Automatically dimming using the internal photocell of the unit
oconnect pin 23 (“Annun Bright/Dim Output”) to pin 6
3.3.2 POWER AND SIGNALS
Wire aircraft power and aircraft ground according to the associated ACU pins in the Pinout
Diagram. Annunciation signals should be wired from the appropriate system inputs and
outputs to the associated ACU pins in the Pinout Diagram.
3.3.3 HARNESS VERIFICATION
With the MD41 ACU disconnected, turn on the avionics master switch and use an ohm-meter
to verify that aircraft power and panel lighting bus power is on the appropriate pin(s) with
appropriate voltage. Also verify that aircraft ground is applied to the appropriate pins.

REV. A February 21, 2011 8 Manual Number 9017211
3.4 MOUNTING
Refer to Section 2: Pre-Installation Considerations in regards to equipment location.
The MD41 ACU is designed for rear panel mounting only. A cutout should be made in the panel in
accordance with Figure 3.4 for the unit bezel and two mounting holes. A cutout template is available from
Mid-Continent Instruments (reference p/n 8014458) upon request.
Prior to completing the mounting of the unit in the aircraft, make sure to set the Annunciator Dim
Adjustment if automatic dimming is configured for the annunciations. Ideally this procedure is best
performed in a dark cockpit to simulate low-light/night time conditions. Connect the unit to the cable
harness and turn on master power to the instrument panel and lighting bus. Use a small flat-bladed
screwdriver to access the adjustment screw inside the hole on the bottom of the unit. Adjust the screw to
increase or decrease the annunciator lighting brightness to a level appropriate with the rest of the panel
instrument lighting.
Secure the indicator to the panel with two #4-40 x 3/8 flat head phillips screws.
FIGURE 3.3
REAR VIEW OF 25-PIN D-SUB CONNECTOR (J1)
TABLE 3.3
SCHEMATIC PINOUT
Pin # Pin #
1 Annun. GPS input 14 Reserved
2 Annun. VLOC input 15 Reserved
3 Annun. TERM input 16 Reserved
4CDISwitchoutput 17Reserved
5 Bright/Dim Button Backlight input 18 Reserved
6 Annun. Bright/Dim input 19 Reserved
7 Light Test 20 Annun. LOI input
8 Annun. WPT input 21 Reserved
9 Annun. APR input 22 Reserved
10 Annun. MSG input 23 Annun. Bright/Dim output
11 OBS input 24 Annun. SUSP input
12 OBS/SUSP Switch output 25 Ground
13 Aircraft Power (+14V/+28V)
Connector Pinout

REV. A February 21, 2011 9 Manual Number 9017211
Note: Use two 4-40 X 3/8” Flat Head Phillips Screws for Mounting
FIGURE 3.4
OUTLINE DRAWING
MD41-1510
MD41-1512
MD41-1514
MD41-1511
MD41-1513
MD41-1515
0.125
3.20 MAX
3.00
3.25
2.73
0.80
0.156 typ

REV. A February 21, 2011 10 Manual Number 9017211
NOTES:
1) REFER TO GARMIN GTN 6XX/7XX INSTALLATION MANUAL FOR ACTUAL INSTALLATION.
2) ALL WIRING SHALL BE 24 AWG UNLESS OTHERWISE NOTED.
3) MOMENTARY SWITCH FOR TEST. (optional connection)
4) 5 VOLT FOR MD41-1514/1515, 14 VOLT FOR MD41-1512/1513, AND 28 VOLT FOR MD41-1510/1511.
19
6
21
16
23
15
18
ANNUN BRIGHT/DIM (3 OPTIONS)
SPARE
SPARE
AUTOMATIC INTERNAL DIMMING ONLY
10
7
22
11
17
1
4
20
2
12
3
8
9
24
14
25
13
J1
5
MSG ANNUN
CDI SOURCE SELECT
LOI ANNUN
VLOC ANNUN
GPS ANNUN
OBS/SUSP MODE SELECT
TERM ANNUN
WPT ANNUN
APR ANNUN
SUSP ANNUN
POWER GND 2A
5,14 or 28VDC
54
53
15
39
52
16
34
33
55
3
P1002
P1001
OBS ANNUN 14
TEST
LAMP TEST (note 3)
INTERNAL DIMMING
FULL BRIGHT; FROM MD41-ACU CIRUIT BREAKER (14 OR 28VDC)
EXTERNAL DIMMING; (EXCEPT -1514/1515) FROM LIGHTING BUS
14 OR 28VDC AIRCRAFT PWR
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
RESERVED
USE 2A CIRCUIT BREAKER
GTN 6XX/7XX
MD41-151X Series ACU
FROM LIGHTING BUS (for pushbutton lighting, see note 4)
FIGURE 3.5
WIRING DIAGRAM

REV. A February 21, 2011 11 Manual Number 9017211
SECTION 4 OPERATION
4.1 FRONT PANEL CONTROLS AND ANNUNCIATIONS
4.1.1 CONTROLS
CDI Momentary Switch, when pressed, will select VLOC, or GPS presentation on
HSI/CDI
OBS/SUSP Momentary switch, when pressed, will select OBS, or SUSP.
In OBS MODE, this will enable OBS selection input from a remote HSI/CDI
indicator. In SUSP mode, this will suspend automatic waypoint sequencing in
the active flight plan.
All button/switch controls are white backlit. Refer to the operation manual of the GPS/SBAS
System equipment manufacturer for additional operational and functional interface details.
4.1.2 ANNUNCIATIONS
LOI (AMBER) Loss of Integrity: WAAS/GPS detects a position error or unable to
calculate integrity of position
TERM (GREEN) Terminal: Indicates aircraft is navigating within 30 miles of the
departure or arrival airport
APR (GREEN) Approach: Indicates the approach is active
MSG (WHITE) Message: Indicates message(s) is active
VLOC (GREEN) VOR/Localizer: NAV/ILS information presented on the HSI or CDI
GPS (WHITE) GPS information presented on the HSI or CDI
WPT (WHITE) Waypoint: Indicates reaching the arrival waypoint
AUTO (WHITE) Automatic sequencing of waypoints is active
SUSP (WHITE) Suspended: Automatic sequencing of waypoints has been suspended
FIGURE 4.1 FRONT PANEL
4.2 LIGHTING BEHAVIOR
Lighting behavior can be controlled in multiple ways. Button lighting is controlled manually using the
aircraft’s panel lighting bus controller. Annunciations can be configured to automatically dim using the
internal photocell, configured to be on full bright, or controlled manually with external dimming
(excluding -1514, -1515) using the aircraft’s panel lighting bus controller when activated.
If using the internal dimming feature for the annunciations, the Annunciator Dim Adjust on the outside of
the unit can be used to set the brightness at their dimmest level for best night-time viewing.

REV. A February 21, 2011 12 Manual Number 9017211
SECTION 5 CONFORMANCE
5.1 CONTINUED AIRWORTHINESS STATEMENT
No periodic scheduled maintenance or calibration is necessary for continued airworthiness of the MD41
series ACU. If the unit fails to perform to specifications, the unit must be removed and serviced by Mid-
Continent Instruments or their authorized designee.
5.2 ENVIRONMENTAL QUALIFICATION STATEMENT
NOMENCLATURE: GPS Annunciator Control Unit (ACU)
MODEL NUMBER: MD41-151X series TSO NUMBER: C129
MANUFACTURERS SPECIFICATIONS:
Minimum Performance Specifications: Test Specification (TS) 187, Test Data Sheet (TDS) 444
QUALIFICATION STANDARD: RTCA DO-160D (* denotes qualification to RTCA DO-160C)
(** denotes qualification to RTCA DO-160F)
CONDITIONS SECTION DESCRIPTION OF TEST
Temperature and Altitude
Low Temperature
High Temperature
Decompression
Overpressure
4
4.5.1
4.5.2
4.6.2
4.6.3
Category F2
Operating Low Temp = -55C
Operating High Temp = +70C
Altitude = 55K
-15,000 ft
Temperature Variation 5 Category C
Humidity 6 Category A
Operational Shock and
Crash Safety 7 Category B
Vibration 8 Category S, Curve M
Category U, Curve G**
(SM/UG)
Explosion 9 Category X
Waterproofness 10 Category X
Fluids 11 Category X
Sand and Dust 12 Category X
Fungus 13 Category X
Salt Spray 14 Category X
Magnetic Effect 15 Category Z
Power Input* 16 Category B
Voltage Spike 17 Category A
Audio Frequency Conducted
Susceptibility 18 Category B
Induced Signal Susceptibility 19 Category A
Radio Frequency Susceptibility* 20
Category T (conducted) Category T (radiated)
[TT]
Emission of Radio Freq Energy* 21 M
Lightning Induced Transient
Susceptibility* 22 Category A3 (pin injection) Category C3 (cable bundle)
[A3C3]
Lightning Direct Effects 23 Category X
Icing 24 Category X
ESD 25 Category A