LBXXXA Series USB Powe
™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11
- 4 -
1. General Information
Introduction
This manual provides information about the installation and operation of the LB478A/479A/480A/LB679A/LB680A and
LB559A/579A/589A model USB power sensors when using the
Power Meter Application
software. The LB4XXA
series (reference to models LB478A/79A/80A and LB679A/80A) of sensors make CW and pulse measurements. The
LB5XXA series of microwave sensors make average - True RMS - (CW or modulated) measurements only. (The
LB480A/LB680A sensors are also capable of making pulse profile measurements
– refer to the Pulse Profile
Application Quick Start Guide and Product Manual for the
Pulse Profiling Application
). This manual also contains
information regarding product features and support, specifications, compatibility, and some measurement examples.
Refer to the product Programming Guide for programming information. The Errata and User Update section at the end
of this document reflects recent changes in product development.
Description
The LBXXXA Series USB Power Sensor features a highly compact power sensor body that connects directly to a
desktop or laptop computer using a standard USB port and standard USB cable(s). A separate power meter is not
required. The LBXXXA Series USB Power Sensors convert RF and microwave power into digital data at the point of
measurement. The companion
Power Meter Application
software provides a front panel display, or Graphical User
Interface (GUI), that allows the user to make typical CW and pulse (modulation) measurements. This application is the
primary subject of this document. A programmatic interface is also supplied with the product.
Sensor zeroing and meter reference calibration are not required. This reduces setup time and simplifies programming.
The unit features optional source Trigger IN/OUT or Recorder OUT connectors in addition to a variety of RF input
connectors. Please refer to the Options section of this document for a complete listing of product options to include
extended performance and support.
Powe™ products address key aspects of general purpose scalar measurements as well as CW, pulse, and
other modulated power measurements.
Powe™ products offer benefits in overall cost, accuracy,
measurement speed, flexibility and test development time.
SPECIAL NOTE:
The RF input connector is field replaceable if the connector type remains the same regardless of
sex. For example: The user can replace an SMA female connector with an SMA male, however, an SMA connector
cannot be replaced with Type-N.
Field replacement of the connector voids calibration and should only be done where
calibration is not required.
USB Considerations
The Universal Serial Bus (USB) provides adequate power for the sensor under normal circumstances. However, when
using a longer cable (greater than 3-5 meters), or when some laptop or portable computers are used, an active or self-
powered hub may be required. These are available at most computer stores and often sell for under $20.00. The
sensor is powered directly via the USB cable and typically draws 450 mA at a nominal 5 VDC. An active hub will
compensate for the DC voltage drop beyond approximately 3-5 meters. The reason an active hub is recommended
when using a portable computer is to conserve the battery life of the computer
. Powe™ products are USB 2.0
compliant. The following information is provided for reference when selecting a hub:
Bus-powered hub:
Draws a maximum of 100 mA at power up and 500 mA during normal operation.
Self-powered hub:
Draws a maximum of 100 mA and
must
supply 500 mA to each port.
Low power, bus-powered functions:
Draws a maximum of 100 mA (often applies to portable computers).
High power, bus-powered functions:
Self-powered hubs: Draws a maximum of 100 mA and
must
supply 500 mA to
each port.
Suspended device:
Draws a maximum of 0.5 mA
