Digital Input/Output; External Trigger - Measurement Computing USB-1608FS User Manual

USB-1608FS User's Guide
Range
±10 V
±5 V
±2 V
±1 V
Table 4 summarizes the noise performance for the USB-1608FS. Noise distribution is determined by gathering
50 K samples with inputs tied to ground at the user connector. Samples are gathered at the maximum specified
sampling rate of 50 kS/s.
Range
±10 V
±5 V
±2 V
±1 V

Digital input/output

Digital type
Number of I/O
Configuration
Pull-up/pull-down configuration
Input high voltage
Input low voltage
Output high voltage (IOH = –2.5 mA)
Output low voltage (IOL = 2.5 mA)
Power on and reset state

External trigger

Parameter
Trigger source (Note 3)
Trigger mode
Trigger latency
Trigger pulse width
Input high voltage
Input low voltage
Input leakage current
TRIG_IN is a Schmitt trigger input protected with a 1.5K Ohm series resistor.
Note 3:
Table 3. Accuracy components - All values are (±)
% of Reading
0.04
0.04
0.04
0.04
Table 4. Noise performance
Typical counts
10
10
11
14
Table 5. Digital I/O specifications
Table 6. External trigger specifications
Conditions
External digital
Software selectable
4-2
Gain error at FS (mV)
4.00
2.00
0.80
0.40
LSBrms
1.52
1.52
1.67
2.12
CMOS
8 (DIO0 through DIO7)
Independently configured for input or output
All pins pulled up to Vs via 47 K resistors (default).
Positions available for pull down to ground. Hardware
selectable via zero ohm resistors as a factory option.
2.0 V min, 5.5 V absolute max
0.8 V max, –0.5 V absolute min
3.8 V min
0.7 V max
Input
Specification
TRIG_IN
Edge sensitive: user configurable for
CMOS compatible rising or falling edge.
10 µs max
1µs min
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
±1.0µA
Specifications
Offset (mV)
1.66
0.98
0.51
0.28