GT 200-10

TIME INTERVAL COUNTER

Product Benefits:

• Compare to the best counters on the market
• Superior capability at a remarkably low price
• Exceptional resolution in time and frequency
  • 100 pS (0.1 nS) without averaging
  • 10 digits/S in frequency (7 digits in 1 mS)
• Matched 100 MHz input channels
• Complete instrument-on-a-card

SUPERIOR PERFORMANCE

The GT200-10 Time Interval Counters are currently in use in thousands of applications ranging from satellite tracking to monitoring of atomic clocks. They include all of the functions normally found on premium counters: Time Interval, Frequency, Period, Totalize, Ratio, Time Interval Delay, and Pulse Width. Unlike many other boards of its kind, these instruments deliver worry-free results, and their inputs are high instrumentation quality, with the sensitivity and damage protection features common to all high quality counters.

The ability to precisely resolve frequency and time yields both increased accuracy as well as reduced measurement time. For example, with the GT200-10 you can determine any frequency to 0.1 part per million (seven digits) in just 1 mS, and resolve each time measurement to 100pS. Couple that with 2300 measurements per second, one of the fastest rates available and you can acquire more data in a single second than a typical GPIB counter can in one minute! Faster measurements and higher resolution, along with built-in statistics functions give you a more thorough analysis of your signal. Standard deviation, peak to peak jitter, or a graph of the measurements are available at the push of a button.

SYSTEM OR BENCH-TOP APPLICATIONS

You can operate the GT200-10 counters just like conventional bench-top instruments with the standard Virtual Front Panel software which uses the power of a PC to speed and simplify data acquisition and analysis. You can view instant plots of your measurements or save them to disk without any programming. In system applications, you can read and control the GT200-10 from a test program using a set of library functions for C, a Windows DLL, or a labVIEW driver.

EXCEPTIONAL VALUE

Because these instruments reside inside a PC, you can acquire superior counter capability for a remarkably low price. The GT200-10 compares very well, in terms of performance, flexibility, and ease of use, the premium priced instruments that sell for $4,000 to $12,000.

GT 200-10 SPECIFICATIONS

INPUT CHARACTERISTICS

Channels A and B

• Frequency range: DC to 100 MHz
• Signal operating range: +5 V to -5 V
• Coupling: DC
• Sensitivity:
  • Sine:
    • 25 mVrms DC - 20 MHz
    • 50 mVrms 20 MHz - 50 MHz
    • 200 mVrms 50 MHz - 100 MHz
  • Pulse: 500 mV pk-pk at 5 ns pulse width
• Impedance: Software selectable, 1 K W || 30
• pF or 50
• Trigger (threshold) level:
  • Range: ± 5.00 V in 40 mV steps
  • Accuracy: ± 3% of setting ± 0.04 V
• Auto Trigger: Automatic selection of optimum
• trigger level
  • Signal repetition rate: 100 Hz to 75 MHz
• Max. signal input:
  • 1 k : 15 V rms (DC to 1 MHz), 5 V rms (above 1 MHz)
  • 50 : 5 V rms
• Arm/Oscillator Input
• Impedance: >500
• Max. input voltage: 15 Vrms
• When used as 10 MHz oscillator input:
  • Coupling: AC
  • Sensitivity: 150 mV rms sine, 450 mV pk-pk pulse
• Duty ratio: 40% to 60%
• When used as Arm input (GT200 only):
  • TTL compatible (1.4 V threshold)
  • Min. pulse width: 15 ns
  • Coupling: DC

MEASUREMENT FUNCTIONS

Frequency A or B

• Range: DC to 100 MHz
• Gate time: 250 µs to 3200 s (plus up to one signal period)
• Number of significant digits: 10 per second of gate time, e.g., 7 digits in 1 ms
• Least Significant Digit (LSD):
  

• Resolution (in Hertz):
  

• Accuracy (in Hertz):

FastFrequency A or B

• Range: DC to 100 MHz
• Gate time: 4 signal periods, fixed
• Accuracy (in Hertz):

Time Interval A to B or Time Interval B to A

• Range: -1 ns to 100,000 seconds (> 25 hr)
• Least Significant Digit (LSD):
  • 100 ps
• Resolution:
  
• Accuracy:
  
• Min. pulse width: 8 ns
• Delay: Recognition of stop events is inhibited for a set time
  Range: 20 µs to 3200 seconds

Totalize and Gated Totalize, A or B

• Control: Count gate can be controlled by software, or by events on the second input channel (Gated Totalize). In Gated Totalize, start and stop event slopes are selectable
• Count rate: DC to 50 MHz, 10 ns min. pulse width
• Modes:
  • Software gate: Gate and count reset are controlled by software
  • Hardware gate: Count is reset before every gate
  • Accumulative: Count is totalized over multiple gates
• Range: 0 to 2.8 x 10¹⁴ counts
• Accuracy: ± 1 count, reading allowed while counting

Period A or B (Single Period)

• Range: 25 ns to 100,000 seconds
• See “Time Interval” for resolution and accuracy

Period A or B (Multiple Period Average)

• See “Frequency” for range and gate time
• Least Significant Digit (LSD):
  

• Resolution:
  
• Accuracy:
  

Ratio A/B or B/A

• Gate time:
  250 µs to 3200 s
• Range: DC - 100 MHz on either input. DC - 25 MHz on second input
• Least Significant Digit (LSD):
  

  FREQhi = higher frequency input

• Resolution and accuracy:
  

  FREQ low= lower frequency input

Width A or B

• Accuracy: Same as Time Interval, plus 3 ns

Pacer

• Automatically initiates measurements at user specified time intervals
  Interval = 0.8 ms to 3200 seconds

GENERAL

Compatibility

• Takes 1 full size ISA slot in any PC/XT, PC/AT or compatible
• A set of DLL’s for Windows 3.x/95/98/NT
• A set of library functions for Microsoft C in DOS

Maximum Measurement Rate

• For any PC:
  • 2300/sec for FastFrequency and all time modes
  • 1400/sec for Frequency and Period modes

Signal Slope

• Programmable on Channel A, Channel B, Arm Start, and Arm Stop

Arming

• Available on all modes, except Totalize
• Arm setup time: Min. 40 ns before selected event

Time Base

• Standard: 10 MHz TCXO
  • Temperature: ± 1 ppm, 0^o to 50^o Celsius
  • Aging: < 1 ppm/yr. or < 1x10^-7/month
  • Supply voltage: < 1x10^-9
  • Short term: <2x10^-10
• External reference input
  • Arm/Oscillator input (all modes)
  • Second signal channel (in single-channel measurements)

Power Requirements (Typical From Computer)

• +5 V @ 0.9 Amp
• -5 V @ 0.05 Amp
• +12 V @ 0.2 Amp
• -12 V @ 0.02 Amp

Supplemental Definitions

• Trigger Error: Error due to noise superimposed on the input signal from both internal and external sources
  

  En = rms noise of input signal (100 MHz bandwidth)

• Trigger Level Timing Error: Time error due to threshold uncertainty
  

  En = rms noise of input signal (100 MHz bandwidth)

• Time Base Error: Fractional frequency error of time-base reference, times the measurement result