MD23-190
User Guide
Mid-Continent Instruments and Avionics
2
User Guide UG190, Revision 2
January , 2021
1.1
INTRODUCTION
The model MD23-190 multifunction clock is a standard 2-inch (2-
¼”) panel-mounted instrument
that displays time, with or without an ARINC input for GPS synchronization, and offers several
timers and related time functions. Based on Mid-Continent Instruments and Avionics patented
FLEX
TM
Custom Function Display, this FAA and EASA TSO-approved instrument brings a highly
capable and modern addition to the cockpit to display required information and provide useful
supplementary functions.
This User Guide is a supplement to the Installation Manual and Operating Instructions (IM),
MCIA part number 9019161. The IM contains all information associated with the standard
product, including installation procedures, product specifications, operating instructions,
certification data, and maintenance requirements. This User Guide provides additional
information associated with the specific features of the multifunction digital counter drum
altimeter. It addresses product identification, electrical pinout, initial configuration setup, and in-
flight user operation.
1.2
PRODUCT IDENTIFICATION
Each MD23 is comprised of certified hardware and certified software. Within the context of the
certified software is a set of data items that can configure and customize the behavior of the unit.
This set of data is referred to as a Custom Instrument Definition, or a CID file. The CID file for
this instrument is pre-loaded and may be available for future updates via a standard USB flash
drive through the programming port on the rear of the unit.
A unique CID number has been assigned specifically to this application. The CID is identified by
its two-digit number and an alphabetic character representing the CID versi
on, starting with “A”.
The identification of the hardware, software, and CID configurations are listed below. Both the
software version and the CID can be viewed on the Introduction Screen during the first few
seconds of applying power to the unit. This information can also be accessed on the Info page of
the Options Menu during Flight Mode.
1.3
PRODUCT FUNCTION
The CID identified within this User Guide is designed as a multi-function clock. It displays UTC
time and Local time and contains multiple timers such as count up, count down, and Elapsed
Flight time. It can receive ARINC 429 inputs to provide time synchronization with a GPS source
and Estimated Time to Waypoint. The highly accurate internal clock maintains time to ±2 minutes
per year when not sync’d, including a 10-year internal battery to keep time when the unit is
powered off. Additional Hobbs and Run timers track usage over the life of the product with the
Flight and Hobbs timers capable of being triggered via an external signal. The clock can also
output currently displayed time via ARINC to external equipment.
Unit Versions
Hardware Part Number
Software Version
CID
6420023-1
1.0.2, or later
90A, or later
