Inductive Effects - National Instruments NI 6602 User Manual

Chapter 3 Signal Connections

Inductive Effects

NI 660x User Manual
For high-speed signals, inductive effects can degrade signal integrity and
cause ringing. To minimize inductive effects, you must minimize ground
loops and allow a return path for currents. Twist your signal with a ground
wire when you connect it to the 68-pin connector block you are using.
Connect the signal wire to the PFI pin you are using and connect the ground
wire to the adjacent D GND line with which the PFI line is twisted.
Figure 3-11 shows an example of wiring that minimizes inductive effects.
SCB-68
PFI 39 Pin 2
GND Pin 36
Figure 3-11. Example of Wiring That Minimizes Inductive Effects
The SH68-68-D1 cable is designed to help minimize inductive effects.
Each signal line is twisted with a ground wire connected to a nearby pin.
Each ground wire is shared by two signal lines.
Table 3-9 lists the signals and the D GND pin number on the 68-pin
connector block.
Table 3-9. Signals and D GND Pin Number on 68-Pin Connector Block
PFI Number
PFI 0
PFI 1
PFI 2
PFI 3
PFI 4
PFI 5
PFI 6
PFI 7
PFI 8
PFI 9
Pin Number for D GND
3-20
Output of External Device
GND
11
11
46
46
14
14
49
49
50
50
ni.com