©
National Instruments Corporation
27
NI WSN-3230/3231 User Guide and Specifications
Digital I/O
Number of channels ...............................................2
Power-on output state.............................................High impedance
DIO pin capacitance...............................................2000 pF
Digital Input
Modes (configurable per channel) .........................
24V Sinking with Power Management
Input voltage range ................................................0 to 30 VDC maximum
Digital input logic level thresholds
TTL Logic and Contact Closure modes
High level (ON) input voltage
...............≥
2
V
Low level (OFF) input voltage
...............≤
0.8 V
24V modes
IEC 1131-2 compatibility ......................Type 1 and 3
High level (ON) input voltage
...............≥
10 V
High level (ON) input current
................≥
2 mA
High level (OFF) input voltage
..............≤
6 V
Low level (OFF) input current
...............≤
1
mA
Input current
TTL Logic and Contact Closure modes
.........≤
375
μ
A at 30 V
≤
110
μ
A at 5 V
≤
80
μ
A at 3 V
Contact Closure mode pull-up current
...........≤
175
μ
A through closed contact
24V modes
.....................................................≤
6.4 mA at 30 V
≤
3.2 mA at 15 V
Minimum detectable pulse width
TTL Logic mode ............................................30
μ
s
24V modes .....................................................30
μ
s
Contact closure mode.....................................100
μ
s
Digital Output
Modes (configurable per channel) .........................
,
High and Low (Sinking and Sourcing)
Logic (Open-Collector with Pull-Up)
DIO power supply voltage range (V
DIO_PWR
) ........3.3 to 24 V
Sourcing current (one channel)..............................250 mA maximum
Sinking current (per channel) ................................1 A maximum
Output voltage
Sourcing .........................................................>(V
DIO_PWR
–750 mV) with I
OUT
<0.25 A
Sinking ...........................................................<90 mV with I
OUT
<1 A
3V TTL Logic mode pull-up .........................>2 V with I
OUT
<20
μ
A
