Table 2-16 – National Instruments SCXI-1121 User Manual
Page 57
Chapter 2
Configuration and Installation
© National Instruments Corporation
2-41
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
SCXIbus Line
SCXI-1121
Rear Signal
Connector
MIO-16
Lab-NB/Lab-PC
Lab-PC+/Lab-LC
PC-LPM-16
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