The IFD Evo Slave EMS (Engine Monitoring System) is a digital avionics instrument designed for non-certified and microlight aircraft. Manufactured by the Italian company M.A.V. Avionic (branded as IFD-NET), it serves as a secondary or "repeater" display for engine data.
In the UK, these units are popular for modernising cockpits because they fit into standard 80mm (3.125 inch) panel holes, allowing pilots to replace bulky analogue gauges with a single, sunlight-readable digital screen.
System Overview: Master vs. Slave
The "Slave" designation is the most important part of the description. An EMS system from IFD-NET typically consists of two types of units:
EMS Master: This is the primary computer. It has the physical connections (ports) for all the engine sensors (e.g., EGT, CHT, Oil Pressure, RPM, Fuel Flow). It processes the raw data and displays it.
EMS Slave: This unit does not connect directly to engine sensors. Instead, it connects to the Master unit via an RS485 digital bus. It acts as a remote display, mirroring the data from the Master.
Key Features of the "EVO" Range
The "Evo" (Evolution) series is the latest generation of these instruments, featuring several hardware improvements over the older IFD-NET models:
Large Round Display: The screen is a 78mm ultra-high-definition round display.The bezel (the metallic frame) has been reduced to less than 2mm, providing the largest possible viewing area for a standard 80mm hole.
Sunlight Readability: The display is extremely bright (up to 1200 cd/m², with special releases up to 2000 cd/m²), making it clear even in direct sunlight—a common issue in bubble-canopy microlights.
User Interface: It uses a double aeronautical rotary knob with a push-switch for navigating menus, which is easier to use than touchscreens or small buttons when flying in turbulence.
Aural & Visual Alarms: You can set min/max parameters.If a limit is exceeded (e.g., oil pressure drops too low), the display will flash the reading and can provide an audio warning to the pilot's headset.
Why use a Slave unit?
The most common reasons for adding an Evo Slave EMS to your panel include:
Co-Pilot Display: If you have a tandem or side-by-side aircraft and want the engine data visible to both occupants.
Dedicated Layouts: You might use the Master unit to show primary flight data (like an Artificial Horizon) while the Slave unit is dedicated solely to full-time engine monitoring.
Redundancy: It provides a second screen to view critical engine data if the primary display is switched to a different page (like a moving map).
