National Instruments 321906B-01 用户手册

©

 National Instruments Corporation

D-1

This appendix contains architecture drawings for the NI 2501 and NI 2503 
switch cards. The drawings show the signal names that are used when the 
boards are in two-wire mode. To make these drawings relevant for 
one-wire mode, four-wire mode, or 6 x 4 matrix mode, use the signal names 
shown in Figures 1-2 through 1-4, respectively, in Chapter 1, 

.

Relay or switch names are based on the signal names where applicable. For 
example, the switch that connects CH9+ to COM1 and CH9– to COM1– is 
named CH9. 

For the other configuration relays, the names are as follows:

•

For the relays that connect banks, the switch name is BCx-y, where 
x and y are the bank numbers that are being connected.

•

For the relay that switches 1-Wire Lo Ref to COM0–, the name is 
1WIRE.

•

For the relay that switches CHx+ or CHx– to COM0+, the name is 
HLSELECT.

•

For the Amp Select switches (NI 2501 only), the names are AMP0 and 
AMP1.