National Instruments SCXI-1121 Manuel D’Utilisation

© National Instruments Corporation

The digital timing signals are pins 36 and 43.

•

Pin 36 is used as a clock by the SCXI-1121 to increment the 
MUXCOUNTER after each conversion by the data acquisition board 
during scanning. This signal is referred to as SCANCLK. See 
Chapter 3, 

, for a description of MUXCOUNTER.

•

Pin 43 is a reserved digital input.

The following specifications and ratings apply to the digital I/O lines.

Absolute maximum voltage 

Input rating

5.5 V with respect to DIG GND

Digital input specifications (referenced to DIG GND):

V

IH

 input logic high voltage

2 V minimum

V

IL

 input logic low voltage

0.8 V maximum

I

I

 input current leakage

±1 µA maximum 

Digital output specifications (referenced to DIG GND):

V

OH

 output logic high voltage

3.7 V minimum at 4 mA maximum

V

OL

 output logic low voltage

0.4 V maximum at 4 mA maximum

Table 2-16.  SCXIbus to SCXI-1121 Rear Signal Connector to Data Acquisition Board Pin Equivalences

MOSI

SERDATIN

ADIO0

PB4

DOUT4

D*/A

DAQD*/A

ADIO1

PB5

DOUT5

INTR*

SLOT0SEL*

ADIO2

PB6

DOUT6

SPICLK

SERCLK

EXTSTROBE*

PB7

DOUT7

MISO

SERDATOUT

BDIO0

PC1

DIN6