National Instruments 321906B-01 用户手册

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 National Instruments Corporation

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This manual describes the electrical and mechanical aspects of the 
NI 2501 FET multiplexer and the NI 2503 mechanical relay multiplexer 
and contains information concerning their installation and operation. 
This manual uses the term NI 2501/2503 whenever information applies 
to both instruments.

This section summarizes the features and operation of the NI 2501/2503 
switch card. Refer to Chapter 2, 

, for more 

complete details. In addition, refer to Appendix A, 

, 

for detailed specifications of the two switch cards.

The NI 2501 is a FET switch card, and the NI 2503 is an armature 
relay switch card. Each consists of a 24 x 1 two-wire multiplexer in 
PXI/Compact PCI format. You can take advantage of the switch card’s 
flexibility to handle a wide variety of test systems through the use of 
various accessories and software configurations. You can use the National 
Instruments NI-SWITCH software included with your kit to configure and 
operate the NI 2501/2503 switch card.

The NI 2501/2503 can also operate as two 12 x 1 or four 6 x 1 two-wire 
multiplexers. You can use software-configurable switches to configure 
the switch card as a 48 x 1 one-wire multiplexer for making large numbers 
of common referenced measurements. In addition, the NI 2501/2503 can 
operate as a 12 x 1 four-wire multiplexer to handle resistive measurements, 
such as thermistors or RTDs. Finally, you can use a National Instruments 
TB-2606 terminal block to further configure the NI 2501/2503 as a 6 x 4 
two-wire matrix. 

 section of this chapter contains more information 

on one-wire, two-wire, four-wire, and matrix configurations, and includes 
diagrams of the pinout connections to make.