Counter; Quadrature Inputs - Measurement Computing USB-1808X User Manual

USB-1808X User's Guide

Counter

Parameter
Terminal names
Number of channels
Resolution
Counter type
Counter input modes
Input type
Input source
Scan clock source
Trigger source
Counter read clock
Period/pulse width resolution
Input high voltage
Input low voltage
Schmitt trigger hysteresis
Input frequency
Schmitt trigger hysteresis
Input high voltage threshold
Input low voltage threshold
Input low voltage limit

Quadrature inputs

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