Справочник Пользователя для National Instruments NI 781xR

© National Instruments Corporation

Exceeding the maximum input voltage ratings listed in Table B-2, 

, can damage the NI 781xR and the computer. NI is not liable for any 

damage resulting from such signal connections.

Do not short the DIO lines of the NI 781xR directly to power or to ground. Doing 

so can damage the NI 781xR by causing excessive current to flow through the DIO lines.

You can connect multiple NI 781xR digital output lines in parallel to 
provide higher current sourcing or sinking capability. If you connect 
multiple digital output lines in parallel, your application must drive all of 
these lines simultaneously to the same value. If you connect digital lines 
together and drive them to different values, excessive current can flow 
through the DIO lines and damage the NI 781xR. Refer to Appendix A, 

, for more information about DIO specifications. Figure 2-2 

shows signal connections for three typical DIO applications.

Figure 2-2.  Example Digital I/O Connections

*3.3 V CMOS

 †

Use a pull-up resistor when driving 5 V CMOS devices

LED

TTL, LVTTL, CMOS, or LVCMOS Signal

+5 V

Switch

I/O Connector

DGND

NI 781xR

DIO<0..3>

DIO<4..7>

+5 V

5 V CMOS

†

TTL or 
LVCMOS*

 

Compatible
Devices

DGND