National Instruments SCXI -1122 Rear Signal Connection Descriptions

Chapter 3 Signal Connections

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.