National Instruments NI PCI-6541 用户手册

© National Instruments Corporation

Tables 8 and 9 describe the different conditions indicated by the two 
NI PXI LEDs.

1, 4, 7, 10, 13, 
16, 19, 22, 25, 
28, 31, 34, 37, 
40, 43, 46, 49, 
52, 55, 58

GND

Ground

Ground reference for signals.

11, 12, 68, 69

RESERVED

N/A

These terminals are reserved for 
future use. Do not connect to 
these pins.

Table 7.  NI 654X/655X/656X SMB Connectors

CLK IN

Reference/
Clock Input

Control

Terminal for the external Reference 
clock used for the PLL or for the 
external Sample clock used for 
pattern generation and/or 
acquisition.

PFI 0

Programmable 
Function 
Interface 
(PFI) 0

Control

Input terminal to the device for 
external triggers, or output terminal 
from the device for events.

CLK OUT

Reference/
Clock Output

Control

Terminal for the exported PLL 
Reference clock or the exported 
Sample clock.

Table 8.  ACTIVE LED Indicators

Off

Device not armed, not triggered, or experiencing an error.

Amber

Device armed and awaiting Start trigger. If performing a 
dynamic acquisition operation, the device may be acquiring 
pretrigger samples.

Green

Device received Start trigger.

Red

Error condition.

Table 6.  NI 656X DDC Connector Pins (Continued)