What seems inescapable, the never-ending rise in signal speeds, coupled with the never-ending rise in accelerating time-to-market pressure, is challenging designers and quality-assurance (QA) engineers to do more in less time. In this vein, some recent introductions in the digital storage oscilloscope (DSO) domain are certainly helping out. A trend is evolving where the functionality of DSOs and PCs is becoming more closely linked.
As Pete Cipriani, product marketing manager at Gould Instrument Systems, Valley View, Ohio, points out, "Without a doubt, we are entering into a new generation of oscilloscope instrumentation with the PC offering a whole slew of features for the DSO user." The new generation includes the embedding of a PC into an oscilloscope product. Today, 95% of DSOs regularly move data to a PC. There are good reasons for doing this—a better display, more processing power, and much more powerful analysis capability in the DSO. Much better conductivity is provided with regard to sharing data, archiving data, and report generation.
DSOs have been around since the mid-1970's, and early versions were monochrome. Designers with four signals tended to segment signal viewing into four regions. But now that there are DSOs with screens in full color, designers can make use of the full screen and the full resolution without worrying about losing signals and confusing them with one another because they overlap.
When Hewlett-Packard reorganized the company and broke out its Test & Measurement Group into the newly formed Agilent Technologies, DSOs fell under the latter's umbrella. Recently added features to Agilent's line of Infinium DSOs include voice control and a Windows operating system (Fig. 1). Its line spans bandwidths ranging from 500 MHz to 1.5 GHz, with corresponding sampling rates of 1 to 8 Gsamples/s.
The voice-control feature enables users to free up their hands for other tasks, such as probing multiple signals on a very fine-pitched IC. The response is said to be both speaker and gender independent. This means that there's no need to train the DSO to respond to any particular voice.
Agilent has added a Windows 98 operating system. Also available is a drag-and-drop measurement capability, so measurements may be made on any channel. Users simply drag an icon from the measurement toolbar to the waveform section that they want to measure and then drop it. Furthermore, there's a feature called "easy zooming." It lets users draw a box around the waveform portion that they want to expand and then click inside the box.
A communications test op-tion is available for proving a product's compliance with, for instance, an ANSI and ITU standard. Known as the communications mask test option, it includes a library of templates for compliance tests, as well as a set of adapters for connecting the DSO to the device under test. If a test fails, then the regions of failure are highlighted on the screen.
Gould came out with the very first DSOs over 25 years ago. Today, the company focuses on four-channel, high-performance instruments. Gould's recently introduced Ultima 500 DSO combines the acquisition power of a high-performance, four-channel DSO with the flexibility and features of a PC. It simplifies data handling by moving effortlessly from signal capture to report (Fig. 2). Users will find the Ultima 500's portability especially attractive for those applications where, until now, a separate DSO and a companion PC were required.
The Ultima series offers a 500-MHz bandwidth and up to a 2-Gsample/s sampling rate. Memory is 1 Mbit per channel. The Ultima 500 is supported by an extensive package of trigger tools to qualify the incoming signal for amplitude, time, pulse, gating, and TV. This creates a wide dynamic range in the transient mode with a resolution of 12 bits, at up to 2 Msamples/s.
Featuring a Pentium-class computer and a 10.4-in. SVGA (800- by 640-pixel) color display, the Ultima 500 is easily transformed into a fully configured Windows PC. This enables a direct data interchange with Microsoft Office applications (Word, Excel) as well as other popular analysis and report-generation packages. In addition, this DSO includes a large and flexible data storage capability with an internal 8.4-Gbyte hard-disk drive and removable 1.44- or 120-Mbyte floppy-disk drive alternatives.
"It's the PC embedded in our DSO that allows people to install all of their own software," remarks Cipriani. This is claimed to be a unique arrangement, exclusive to Gould. Embedding the PC eliminates the need for users to move the data, which can be a repetitive and laborious task.
Gould offers what supposedly is the only true 12-bit DSO. "This means that while most other DSOs employ 8-bit converters, the 12-bit capability of the Ultima offers better accuracy—4096 bits for 12-bit conversion quantized values—versus 256 bits for 8-bit conversion quantized values. The input amplifiers are accurate within 0.1%, whereas most DSOs are typically within 2%," states Cipriani.
"A four-channel arrangement is valuable because signal interaction is an integral part of testing. Often, two channels just don't get it done," Cipriani adds.
A dual-mode interface combines the look and feel of both a DSO and PC in a single integrated operating system. Adjustments are accessible via either traditional front-panel controls or a mouse and keyboard. Ease of use is further simplified by implementing the on-board menu editor that enables customization of the user interface. This limits menu selections to those required for any given application.