
VESDA ECO Detector by Xtralis
Product Guide
17898_05
Principles of Operation
29
Current Outputs
The ECO unit has two local analogue outputs, labeled as A & B, which are used in
a 4-20 mA source configuration.
Current output A is mapped to indicated the level of the Sensor 1 Gas reading. The
4mA level is mapped to a gas reading of 0, the 20mA level is mapped to the
maximum sensor measurement (e.g. 25%v/v when using an oxygen sensor).
Accordingly, Current output B is mapped to indicate the level of the reading of the
Sensor 2 gas reading.
Fault Conditions
During Fault conditions the current outputs will be driven to a 3.5mA Fault level,
independent of the selected monitor type.
Gas Calibration Conditions
During calibration periods, the relative current outputs will be driven to a set 2mA
level, independent of the selected monitor type.