Bird Technologies BDS-Manual - Manual (Page 17)

3
Items Supplied
•
Receiver unit
•
Instruction Manual
•
BDS GUI Software
Communication Options
The Bird Diagnostic System offers the following methods of communication:
•
BDS GUI
•
DeviceNet
•
Customer defined
Theory of Operation
The Bird Diagnostic System (BDS) is a real-time RF measurement system that consists of a sensor, a sensor cable, and a
receiver. The sensor is mounted in the host system’s RF delivery system where it simultaneously measures voltage and
current (both magnitude and phase of each) and sends the data to the receiver. Each component of the BDS (sensor,
sensor cable, receiver) is calibrated separately and contains its own calibration constants which permits interchange-
ability without recalibration. A sensor, sensor cable, or receiver can be replaced with minimal loss of accuracy.
The receiver processes the sensor data and makes it available to the communication ports. The receiver consists of RF input
conditioning circuits, A/D converters, a high-speed signal processor, and input / output connectors (Figure 3, page 3).
The A/D converters convert the analog RF signal to digital information for processing; the high-speed signal proces-
sor converts the signal from the time domain to the frequency domain while maintaining the correct phase relation-
ship of each harmonic to its fundamental frequency.
The output of the BDS contains information about the RF including up to five fundamental frequencies (amplitude of
both voltage and current and their phase for each fundamental frequency) and up to 15 overtones for each fundamen-
tal frequency (amplitude of both voltage and current and their phase for each harmonic, and also the phase relation-
ship of each harmonic to the voltage component of its specific fundamental frequency). With this data set (voltage,
current, and phase), power (
) and impedance ( ) can be determined for each fundamen-
tal and harmonic frequency.
Users can choose number of fundamental frequencies (up to five) and associated harmonics (up to 15 for each fun-
damental frequency) that are acquired and processed. Choosing a small number of fundamental and harmonic fre-
quencies reduces the computing time and, therefore, provides output data faster than choosing a larger number of
fundamental and harmonic frequencies. See “Frequency Tracking” on page 40.
The host system can communicate with the BDS receiver through any of the methods outlined in Communication
Options, page 3.
Figure 3 Bird Diagnostic System Block Diagram
p v i θ cos Ч Ч = Z v i ÷ θ ∠ =