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Model T940 User Manual
Publication No. 980938 Rev. K
Specifications 7-8
Astronics Test Systems
Counter/Timer Characteristics
Measurement Modes
Frequency
Period
Time Interval
Totalize
Timed Totalize
Positive Pulse
Negative Pulse
Input Source
CH1-32 (Uses Good 1)
AUX1-12
Frequency Synthesizer
VXICLK10
250 MHz
Pulse Generator
Input Sense
Rising/Pos or Falling/Neg
Frequency/Period
Measurement Source
Input 1
Frequency/Period
Measurement Range
0.25 Hz to 250 MHz/4 ns to 4 s
Preset Aperture Windows
1 µs to 10 s in decade steps
Aperture Window Accuracy
0.1% +50 ppm
Frequency/Period
Measurement Resolution
≥4 Digits with a 1 ms Aperture
≥5 Digits with a 100 ms Aperture
≥6 Digits with a 10 s Aperture
Time Interval Functions
Between Inputs 1 & 2; Positive/Negative
Pulse Width of Input 1
Time Interval Range
~2 ns to ~4.29 s
Time Interval Resolution
1 ns
Time Interval accuracy
1 count + input comparator threshold
uncertainty
Time Interval Reference
Accuracy
50 ppm
Totalize (2 modes)
Timed with a Preset Aperture.
Aperture defined by Input 3.
Preset Aperture accuracy
50 ppm
Max. Count
2^32-1
Max. Input Data Rate
250 MHz
Note: CH and AUX input technology may
limit the max. data rate that can be
supported.
Input Trigger
Input 3