© National Instruments Corporation A-1 PC-OPDIO-16 User Manual
Appendix ASpecifications
This appendix lists the specifications of the PC-OPDIO-16. These specifications are typical at 25°C and 50%
relative humidity unless otherwise stated. The operating temperature range is 0° to 50°C.

I/O Connector Electrical Specifications

Compatibility ...............................................................TTL-compatible
Configuration............................................................... 8 dedicated optically isolated digital input channels and
8 dedicated optically isolated digital output channels

Digital Input

Input Characteristics

Number of channels..................................................... 8, each with its own ground reference isolated from other
channels.
Maximum input voltage...............................................24 VDC or 24 VAC
Digital logic levels.......................................................
Level Min Max
Input low voltage
(DC or Peak AC) —±1 V
Input high voltage
DC
1 kHz AC ±2 VDC
4 Vrms ±24 VDC
24 VAC
Input current
5 V inputs............................................................1.5 mA/channel
24 V inputs..........................................................7.0 mA/channel
Data transfer rate1
.........................................................1 kHz
Isolation........................................................................24 VDC from computer ground

Digital Output

Output Characteristics

Number of channels..................................................... 8, each with its own common reference and supply pins
isolated from other channels
Supply voltage range....................................................5 to 24 VDC

1
The input data transfer rates are limited by the switching characteristics (turn-on time, switching time, and turn-
off time) of the optical isolator used on the board. The transfer rates also depend on the computer, CPU speed,
and software used.