The GTX22x0 family of PXI universal time interval counters offer many of the measurement and timing functions of high-end stand-alone frequency counters, including accumulate, auto ratio, frequency, fast frequency (GTX2220 and GTX2230 only), period, ratio, single period, test clock, time interval, time interval delay, totalize, totalize gated, totalize gated once, & pulse width.
There are three models available: the GTX2210, GTX2220 and GTX2230. The GTX2210 frequency range operates to 225 MHz, the GTX2220 covers frequencies up to 1.3 GHz, and the GTX2230 covers frequencies up to 2.0 GHz. The card is also available in PCI format (GC22xx).
The GTX22x0 series counters have two signal input channels via BNC connectors, an external timebase input, arm input, and a gate signal output. The separate input signals can be used for arming and gating the circuitry, and controlling the timing of the analysis (start / stop duration) for maximum measurement flexibilty.
The GTX22x0 series counters use an on-board microprocessor with embedded firmware to off-load processing tasks from the main CPU. The counters use high-density, low-power field programmable gate arrays (FPGA) to perform complex logic tasks. Reciprocal counting techniques are used to achieve high resolution measurements on lower frequency signals without sacrificing measurement time. These techniques provide a fixed number of digits of resolution for all frequencies rather than a fixed resolution in Hz for the same gate time.
The GTX2220 and GTX2230 can measure frequencies to 0.1 parts per million (seven digits) in just 1 ms and resolve each time measurement to 100 ps. This ability to precisely resolve frequency and time allows for increased accuracy as well as reduced measurement time. When combined with 2,300 measurements / second, one of the fastest rates available, more data can be acquired in a single second than a typical GPIB counter can acquire in one minute.
Additionally, the counters include an on-board 10 MHz TCXO timebase for internal frequency reference. As an option, a high precision 10 MHz OCXO is available for the GTX220 and GTX2230 models. An external 10 MHz input is also availble for use with external timebases.
The board is supplied with the GXCNT software, a software package that includes a virtual instrument panel, and a Windows 32/64-bit DLL driver library and documentation. The virtual panel can be used to interactively program and control the instrument from a window that displays the instrument’s current settings and status. In addition, interface files are provided to support access to programming tools and languages such as ATEasy, LabView, LabView/Real-Time, C/C++, Microsoft Visual Basic®, Delphi, and Pascal. An On-Line help file and PDF User's Guide provides documentation that includes instructions for installing, using and programming the board. A separate software package - GtLinux - provides support for Linux 32/64 operating systems.
