Electronics International MVP-50P - Manual (Page 27)

2.8 Install the Interface Circuit for Annunciators:
Any Temperature or Resistive Fuel Level channel on the EDC may be used to monitor the state of a
switch, relay or output from a device. This output can be used to trigger a light (annunciator) on the
MVP. Annunciator lights such as Canopy Latch, Baggage Door, Deice, Pitot Heat, Fire, etc. can be
displayed on the Main or System screen on the MVP.
To monitor a voltage, a VI-221 (Voltage Interface Unit) will be required. This consists of a 221K ohm
resistor heat shrunk between two wires with a D-Sub pin crimped on one end. The following methods
may be used to interface an EDC channel (using a VI-221) to a switch, relay or device:
A. A. A. A. A. Monitoring a Signal That Switches Between Any Voltage and Ground: Monitoring a Signal That Switches Between Any Voltage and Ground: Monitoring a Signal That Switches Between Any Voltage and Ground: Monitoring a Signal That Switches Between Any Voltage and Ground: Monitoring a Signal That Switches Between Any Voltage and Ground:
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B. B. B. B. B. Monitoring a Signal that is Switched to Ground: Monitoring a Signal that is Switched to Ground: Monitoring a Signal that is Switched to Ground: Monitoring a Signal that is Switched to Ground: Monitoring a Signal that is Switched to Ground:
EDC
Temp or Resistive Fuel
Level Channel.
Device, Switch or Relay
Bus or any Voltage
Load
VI-221
EDC
Temp or Resistive Fuel
Level Channel.
Bus
Load
VI-221
VI-221
Device, Switch or
Relay
If a Load does not exist,
an additional VI-221
must be placed in the
circuit as shown. This
provides a pullup for the
switch. Light, Horn, etc.