Custom Application Suite


I designed, developed, and maintained for nearly 20 years this application suite, which consists of over half a dozen applications that control a selection of radio frequency test instruments (including Rohde & Schwarz test receivers, Hewlett-Packard and Advantest spectrum analyzers, ICOM professional receivers, and other devices) over GP-IB and serial interfaces. The suite's client-server model allows users to connect and utilize instruments that are deployed at remote locations. Incorporating an adaptive rate algorithm, the suite makes it possible to control instruments while simultaneously receiving compressed digital audio even over a narrowband dial-up connection. A scheduling module allows the user to configure unattended measurement and voice recording sessions:

Device Selection

This application suite supports a variety of instruments, including several spectrum analyzers and test receivers, signal generators, antenna rotators, and more. Instruments are controlled through GPIB/HPIB, RS-232, or proprietary interfaces like ICOM's CI-V. Additionally, recording and transmission of digital audio is supported.

Instruments are controlled by a remote server co-located with them. Client computers communicate with the remote server using TCP/IP. The suite is designed to function on low-bandwidth connections; simple instrument control is possible even over a cellular modem connection. A regular dial-up connection is sufficient to control a receiver and obtain digital audio in real time. An adaptive transmission algorithm ensures that the suite remains responsive even over unreliable connections.


The instrument interfaces ("virtual instruments") are designed to replicate all important instrument functionality to the remote user. Of particular interest are real-time graphical trances obtained from the instrument and transmitted for visual presentation on the client machine.

In addition to interactive instrument control, the suite also contains components that support background operation. It is possible to schedule high-speed scans, audio recordings, and other background activity.


In addition to the core components, the suite contains several helper applications, including configuration and instrument calibration programs. All components offer a bilingual English-French user interface.