Model: PXI-6608
Description: PXI-6608, 80 MHz, 8 channels, PXI counter/timer module
8 channel, 32 bit up/down counter/timer module
80 MHz maximum source frequency (125 MHz, using a pre-divider)
(32) Digital I/O lines (5 V TTL/CMOS) – 8 dedicated, 24 shared with counter/timer
(3) Synchronous high-speed DMA transmission capability
High precision oscillator
Digital dejitter filter

National Instruments PXI-6608 High Precision counter/Timing with Digital I/ O is a timing and digital I/ O module, Contains eight 32-bit counters/timepieces and 32 lines of TTL/ CMOS-compatible digital I/ O. The NI PXI-6608 features a 10 MHz oven control crystal oscillator for your high-precision applications. You can use the PXI-6608 to perform a variety of counter/timer tasks, including encoder position measurement, event counting, period measurement, pulse width measurement, pulse generation, pulse train generation, and frequency measurement.
National Instruments PXI-6608 PXI counter/timer module
The PXI-6608 (Part number: 777997-01) counter/timing module produced by NI is an enhanced version of the PXI-6602 with the addition of a highly stable clock called an Oven Controlled Crystal Oscillator (OCXO). The module has 8 up/down counters/timers, 32-bit resolution, requires 1 A to 2.5 A power supply, 300 mV Schmidt trigger hysteresis, measurement and source frequencies of 80 MHz each, input impedance of 25 kΩ to 500 kΩ, and output impedance of 75 Ω. In order to achieve these specifications, it is recommended that the preheating time be 5 minutes and the temperature range be 0 °C to 55 °C.
An important function of the National Instruments PXI-6608 module is to prevent double counting or synchronous counting modes. This feature guarantees that the counter generates accurate information in a non-slow or non-periodic external source application. Preventing double counting is only suitable for buffer counter applications, such as measuring frequency or period. During buffered counter application, the counter should save the number of times an external source pulses between the rising edge of the gate signal.
The OCXO on the PXI-6608 counter/timer module determines the accuracy of the user’s time measurement and pulse generation. The OCXO can be run as a GATE or SOURCE for a counter. A third option is to use the OCXO as a PXI backplane clock. Any module that phase-locks to the PXI backplane clock will gain clock stability comparable to the counter/timer module. The universal reference clock signal can be used to coordinate numerous modules in a measurement or control system.
The PXI-6608 runs with NIDAQmx driver software, which is compatible with software packages/application development environments (ades) such as LabVIEW, LabWindows/ CVI or Measurement Studio.
The physical size of the NI device is 16.0 x 10.0 cm. It recommends operating and storage temperature ranges of 0 °C to 55 °C and -20 °C to 70 °C, respectively, and non-condensing operating and storage humidity ranges of 0% to 90% and 5% to 95%, respectively.