National Instruments SCXI -1122 - Manual (Page 33)

Chapter 3 Signal Connections
© National Instruments Corporation 3-11 SCXI-1122 User Manual
Rear Signal Connection Descriptions
Pin Signal Name Description
1, 2 AOGND Analog Output Ground–These pins are connected to the
analog reference when jumper W1 is in position AB-R0.
3, 4 MCH0
±
Analog Output Channels 0–Connects to the DAQ board
differential analog input channels.
19 OUTREF Output Reference–This pin serves as the reference node for
the analog channels output in the pseudodifferential
reference mode. It should be connected to the analog input
sense of the NRSE DAQ board.
24, 33 DIGGND Digital Ground–These pins supply the reference for DAQ
board digital signals and are tied to the module digital
ground.
25 SERDATIN Serial Data In–This signal taps into the SCXIbus MOSI line
to send serial input data to a module or Slot 0.
26 SERDATOUT Serial Data Out–This signal taps into the SCXIbus MISO
line to accept serial output data from a module.
27 DAQD*/A DAQ Board Data/Address Line–This signal taps into the
SCXIbus D*/A line to indicate to the module whether the
incoming serial stream is data or address information.
29 SLOT0SEL* Slot 0 Select–This signal taps into the SCXIbus INTR* line
to indicate whether the information on MOSI is being sent
to a module or Slot 0.
36 SCANCLK Scan Clock–This indicates to the SCXI-1122 that a sample
has been taken by the DAQ board and causes the
SCXI-1122 to change channels.
37 SERCLK Serial Clock–This signal taps into the SCXIbus SPICLK
line to clock the data on the MOSI and MISO lines.
43, 46 RSVD Reserved.
All other pins are not connected.
The signals on the rear signal connector can be classified as analog output signals, digital I/O
signals, or timing I/O signals. Signal connection guidelines for each of these groups are given in
the following section.
Analog Output Signal Connections
Pins 1 through 4 and pin 19 of the rear signal connector are analog output signal pins. Pins 1
and 2 are AOGND signal pins. AOGND is an analog output common signal that is routed
through jumper W1 to the analog reference on the SCXI-1122. You can use these pins as a
general analog power ground tie point to the SCXI-1122 if necessary.