1 OVERVIEW
The USBcount50 is an isolated digital pulse counter that has the following features:
•Single channel pulse counter with BNC input and USB PC interface
•Each USBcount50 can be stacked to increase channel count (each requires its own USB connection)1
•300V Cat II isolation between BNC ground and USB ground2
This means that there is no DC path through the USBcount50 from the counters input to the PC’s ground
•Up to 50MHz input counting, 100MHz with suitable input signal
•10ns timing resolution
•Single shot or continuous update
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•Two modes of operation: Frequency mode or Period mode
•Frequency mode can use 0.1s, 1s or 10s integration times. Large dynamic range of counter means 1s integration setting can be used from 1KHz up to 100MHz i.e. no
•Period mode can use internal 1MHz, 10MHz or 100MHz reference clocks coupled with edge detection logic for rising→rising, falling→falling, falling→rising, rising→falling. Large dynamic range of counter means 100MHz clock setting can be used from 10us up to 26.8s i.e. no
•Period mode (aka reciprocal counting mode) is able to measure frequencies down to below 4mHz.
•Programmable input stage voltage level from 1.5V to 5.0V in 256 steps
•Input protected to 30V DC
•Host powered from USB (200mA typ)
•Stacked configurations of 2,3 and 4 channels are supported
•Power/activity LED
1A stacking connector kit is required
2In stacked configurations the channels share a common ground at the BNC terminals
Elan Digital Systems Ltd. | 5 | USBcount50 USER’S GUIDE Iss1 |