Appendix B Rear Signal Connector
SCXI-1121 User Manual B-2 www.natinst.com
Rear Signal Connector Signal Descriptions
See the Timing Requirements and Communication Protocol section in
Chapter2, C onfiguration and Installation, for more detailed information
on timing. Detailed signal specifications are also included in Chapter2.
Pin Signal Name Description
1-2 AOGND Analog Output Ground—These pins are connected to the
analog reference when jumper W33 is in position AB-R0.
3-12 MCH0± through MCH4± Analog Output Channels 0 through 4—Connects to the data
acquisition 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 data acquisition board.
24, 33 DIG GND Digital Ground—These pins supply the reference for data
acquisition 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 provide 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 Data Acquisition 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-1121 that a sample
has been taken by the data acquisition board and causes the
SCXI-1121 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 RSVD Reserved.
All other pins are not connected.