Measurement Computing DaqBoard 3000USB Series - Manual (Page 102)

7-8 DaqBoard/3000USB Series Specifications 928691 Note: Specifications are subject to change without notice.
Pattern Generation Output
Two of the 8-bit ports can be configured for 16-bit pattern generation. The pattern can be updated
synchronously with an acquisition at up to 1 MHz.
Counters
One Counter Channel, Typical
Each of the four high-speed, 32-bit counter channels can be configured for counter, period, pulse width, time
between edges, or multi-axis quadrature encoder modes. Counter inputs can be scanned synchronously along
with analog and digital scanned inputs, based on an internal programmable timer, or an external clock source.
Channels: 4 x 32-bit
Input Frequency: 20 MHz maximum
Input Signal Range: -5V to +10V
Input Characteristics: 10 k
Ω pull-up, 200Ω series resistor, ±15 kV ESD protection
Trigger Level: TTL
Minimum pulse width: 25 ns high, 25 ns low
Debounce Times: 16 selections from 500 ns to 25.5 ms. Positive or negative edge sensitive;
glitch detect mode or debounce mode.
Time Base Accuracy: 50 ppm (0º to 50ºC)
Five Programmable Modes: Counter, Period, Pulsewidth, Timing, Encoder
1. Counter Mode Options: Totalize, Clear on Read, Rollover, Stop at all Fs, 16-bit or 32-bit, any other
channel can gate or decrement the counter
2. Period Mode Options: Measure x1, x10, x100, or x1000 periods, 16-bit or 32-bit, 4 time bases to
choose from (20.83 ns, 208.3 ns, 2.083 µs, 20.83 µs), any other channel can gate the period
measurement
3. Pulsewidth Mode Options: 16-bit or 32-bit values, 4 time bases to choose from (20.83 ns, 208.3 ns,
2.083 µs, 20.83 µs), any other channel can gate the pulsewidth measurement
4. Timing Mode Options: 16-bit or 32-bit values, 4 time bases to choose from (20.83 ns, 208.3 ns,
2.083 µs, 20.83 µs)
5. Encoder Mode Options: x1, x2, x4 options, 16-bit or 32-bit values, Z-channel clearing of the counter,
any other channel can gate the counter
Multi-axis Quadrature Encoder Inputs:
o 1 channel with A (phase), B (phase), and Z (index)
o 2 channel with A (phase) and B (phase)
o x1, x2, and x4 count modes
o Single-ended TTL