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SYSTEM INTERFACE MODULE (SIM) - Introduction

The System Interface Module (SIM) is used to house interface cards belonging to other systems not included in the forward and aft overhead or the throttle quadrant; for example the korrys that are used in the Main Instrument Panel (MIP), the landing gear and some the avionics located within the center pedestal.  The System Interface Module, if necessary, can be expanded to by adding additional modules.

The SIM is not connected to any other module.  It is a stand-alone module.

Design and Construction

The SIM is designed along the same theme as the Throttle Interface Module (TIM).  The module is constructed from ABS plastic that has been heat welded to ensure strength and longevity; two twin 12 Volt brushless fans provide cooling along with two brushless fans located either side of the module. 

LEFT:  System Interface Module (SIM) showing fans and D-Sub connectors (click to enlarge).

Because the module has a smaller footprint than the TIM, a hinged upper lid is not required; the upper lid is secured to the module body by four thumb screws.   

To improve accessibility to the interface cards and wiring, the module has been designed to allow maximum use of ‘whitespace’.  Likewise, each interface card is mounted on an ABS raised platform ('oil rig') which affords greater depth facilitating easier wire and card accessibility and management.  All wires are colour coded and have labels attached and where possible ferrules have been used to connect the wires to the interface cards.  Like-minded wires navigate to a VGA or serial port connectors (D-Sub connectors) which are securely attached to the end firewall of the module. 

Five straight-through cables connect to the SIM; each cable corresponding to a particular OEM part or system. 

To avoid the possibility of dislodgement, the straight-through cables have screws that allow each cable to be securely attached to the appropriate D-Sub connector.  Each straight-through cable either connects to an OEM module, such as the radar panel, or to a bracket and terminal block that then directs wires to various Canon plugs, etc.

A single USB connection connects the SIM to the computer.  To facilitate the one USB philosophy, a powered Belkin hub is mounted within the module.

Power Requirements

The SIM, due to its varied functionality requires five voltages: 5, 6, 12 and 28 Volts.  

LEFT:  System Interface Module (SIM) with upper lid removed.  Additional 'whitespace' around interface cards enables easier access to cards and wiring (click to enlarge).

5 Volts enables the incandescent backlighting to operate in the OEM gauges.  6 Volts powers the Belkin hub, whilst 12 and 28 Volts provide the power to the landing gear solenoid/relay and incandescent bulbs used in in the MIP annunciators (korrys).

To facilitate the multi-voltage requirement, a power plug has been designed which is secured by two screws to the opposite side of firewall that the straight-through cables are connected.  The multi-voltage wires from the power plug then navigate to a terminal block mounted outside of the module, which acts as a terminus to the connection with whatever voltage power supply is needed (located in the Power Supply Rack (PSR)).

As with all the interface modules, the SIM has been designed for easy removal to a work bench for servicing  or troubleshooting.

Interface Cards and Integral Components

The SIM accommodates several interface cards and relays to provide functionality to the following components:

(i)       Phidget 0/16/16 Interface Kit card – OEM annunciators located on the Main Instrument Panel (MIP);
(ii)      Phidget 0/0/4 Interface Kit card – Landing gear mechanism;
(iii)     PoKeys 55 interface card  – Aural Warning Module (AWM) and RMI gauge;
(iv)     Pokeys 55 Joystick card – Radar module and auxiliary PoKeys connection (expansion);
(v)      12 and 28 Volt busbars – As required
(vi)     Relays – Landing gear mechanism solenoid;
(vii)    Belkin hub – One USB cable philosophy; and
(viii)   MinMax MDW DC converter – OEM yaw dampener and brakes pressure gauge.

NOTE:  The PoKeys 55 card has been configured to be a joystick card in addition to a standard PoKeys card.

The System Interface Module does not incorporate an Interface Alert System (IAS) as it is not a primary module.

Location of Module

The module is mounted on a small three-shelf bench that is located forward of the Main Instrument Panel on the First Officer side. The bench is large enough to adequately store several interface modules while allowing accessibility.

Additional photographs can be found in the picture gallery.