Contents
SCXI-1121 User Manual viii www.natinst.com
Figures
Figure 2-1. SCXI-1121 General Parts Locator Diagram.........................................2-2
Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram........................................ 2-3
Figure 2-3. SCXI-1121 Front Connector Pin Assignment...................................... 2-18
Figure 2-4. Ground-Referenced Signal Connection with
High Common-Mode Voltage.............................................................. 2-21
Figure 2-5. Floating Signal Connection Referenced to Chassis Ground for
Better Signal-to-Noise Ratio.................................................................2-21
Figure 2-6. Floating AC-Coupled Signal Connection............................................. 2-22
Figure 2-7. AC-Coupled Signal Connection with High Common-Mode Voltage.. 2-22
Figure 2-8. Assembling and Mounting the SCXI-1330
Connector-and-Shell Assembly............................................................2-25
Figure 2-9. Nulling Circuit......................................................................................2-29
Figure 2-10. Shunt Circuit.........................................................................................2-30
Figure 2-11. SCXI-1320 Parts Locator Diagram.......................................................2-36
Figure 2-12. SCXI-1328 Parts Locator Diagram.......................................................2-37
Figure 2-13. SCXI-1321 Parts Locator Diagram.......................................................2-38
Figure 2-14. SCXI-1121 Rear Signal Connector Pin Assignment............................ 2-39
Figure 2-15. SCANCLK Timing Requirements........................................................2-43
Figure 2-16. Slot-Select Timing Diagram.................................................................2-44
Figure 2-17. Serial Data Timing Diagram.................................................................2-45
Figure 2-18. Configuration Register Write Timing Diagram....................................2-46
Figure 2-19. SCXI-1121 Module ID Register Timing Diagram............................... 2-47
Figure 3-1. SCXI-1121 Block Diagram...................................................................3-1
Figure 3-2. SCXIbus Connector Pin Assignment....................................................3-3
Figure 3-3. Digital Interface Circuitry Block Diagram........................................... 3-6
Figure 3-4. SCXI-1121 Digital Control...................................................................3-7
Figure 3-5. Analog Input Block Diagram................................................................3-9
Figure 3-6. Analog Output Circuitry.......................................................................3-15
Figure 3-7. Single-Module Parallel Scanning......................................................... 3-17
Figure 3-8. Single-Module Multiplexed Scanning (Direct).................................... 3-18
Figure 3-9. Single-Module Multiplexed Scanning (Indirect).................................. 3-19
Figure 3-10. Multiple-Module Multiplexed Scanning...............................................3-19
Figure 3-11. Multiple-Chassis Scanning...................................................................3-20
Figure B-1. SCXI-1121 Rear Signal Connector Pin Assignment............................B-1
Figure C-1. SCXIbus Connector Pin Assignment....................................................C-2
Figure D-1. SCXI-1121 Front Connector Pin Assignment......................................D-2
Figure E-1. SCXI-1340 Installation.........................................................................E-4