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National Instruments Corporation D-1 NI 2501/2503 User Manual
DArchitecture Drawings
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 Figures1-2 throug h 1-4, respectively, in Chapter 1, Routing
Signals with Your NI 2501/2503.
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
xand 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.