Digital Input; Digital Output; External Digital Trigger; Counter - Measurement Computing USB-234 User Manual

USB-234 User's Guide

Digital input

Parameter
Input voltage range
Input voltage protection
Input high voltage
Input low voltage
Input leakage current
Do not leave a voltage above 3.3 V connected on the DIO line when the device is not powered. This
Note 1:
can cause long-term reliability issues.

Digital output

Parameter
Output low voltage
Output high voltage
Maximum output current per
line

External digital trigger

Parameter
Trigger source
Trigger mode
Input high voltage
Input low voltage

Counter

Parameter
Pin name
Number of counters
Resolution
Counter type
Counter direction
Counter source
Input frequency
High pulse width
Low pulse width
Table 5. Digital input specifications
Condition
Power on
Power off
At 3.3 V
At 5 V
Table 6. Digital output specifications
Condition
4 mA
1 mA
4 mA
1 mA
Table 6. External digital trigger specifications
Specification
TRIG input
Software configurable for rising or falling edge. Power on default is rising edge.
2.3 V min
0.8 V max
Table 7. Counter specifications
Specification
CTR
1
32 bits
Edge counter (rising)
Count up
CTR
5 MHz max
100 ns min
100 ns min
24
Specification
0 V to 5 V
0 V to 3.3 V (Note 1)
±20 V on two lines per port (maximum of five
lines for all ports) for up to 24 hours
2.3 V min
0.8 V max
0.8 mA max
4.5 mA max
Specification
0.7 V max
0.2 V max
2.1 V min
2.8 V min
3.6 V max
±4 mA
Specifications