MCC USB-1808X: High-Speed, High-Precision, Simultaneous USB DAQ Device - User Guide

USB-1808X User's Guide Specifications
22
Counter
Table 11. Counter specifications
Parameter Specification
Terminal names
CTR0, CTR1
Number of channels
2 channels
Resolution
32-bit
Counter type
FPGA
Counter input modes
Totalize, Pulse width, Period
Input type
Schmitt trigger, 33 Ω series resistor, 47 kΩ pull-down to ground
Input source CTR0
CTR1
Scan clock source
Internal input scan clock or external input scan clock (ICLKI pin)
Trigger source  ITRIG (see External trigger on page 24)

Digital pattern detection (see Pattern trigger on page 24)
Counter read clock
Internal or external input scan clock up to 200 kHz
Period/pulse width resolution
20 ns, 200 ns, 2 µs or 20 µs; software-selectable
Input high voltage
2.2 V min, 5.5 V max
Input low voltage
1.5 V max, –0.5 V min
Schmitt trigger hysteresis
0.4 V min, 1.2 V max
Input frequency
50 MHz, max
Schmitt trigger hysteresis 0.76 V typ
0.4 V min
1.2 V max
Input high voltage threshold
1.74 V typ
1.3 V min
2.2 V max
Input low voltage threshold 0.98 V typ
0.6 V min
1.5 V max
Input low voltage limit
–0.5 V absolute min
0 V recommended min
Quadrature inputs
Table 12. Quadrature input specifications
Parameter Specification
Terminal names
ENC0A, ENC0B, ENC0Z; ENC1A, ENC1B, ENC1Z
Number of encoders
2
Signals per encoder
A, B and Z
Resolution
20 ns
Maximum frequency
50 MHz
Minimum pulse width
10 ns
De-bounce function
None
Scan clock source
Internal input scan clock or external input scan clock (ICLKI pin)
Trigger source  ITRIG (see External trigger on page 24)

Digital pattern detection (see Pattern trigger on page 24)
Input high voltage
2.2 V min, 5.5 V max
Input low voltage
1.5 V max, –0.5 V min
Absolute maximum input
voltage
5.5 V