USB-6451 Pinouts

USB-6451 AI Connector Pinout

Use the pinout to connect to analog input terminals on the USB-6451.

Figure 7. USB-6451 AI Connector Pinout


Table 8. USB-6451 AI Connector Pin Assignments
Pin Signal
1 AI 8
2 AI 9
3 AI 10
4 AI 11
5 AI 12
6 AI 13
7 AI 14
8 AI 15
9 AI GND
10 No connect
11 No connect
12 No connect
13 No connect
14 No connect
15 No connect
16 No connect
17 No connect
18 CHSGND
19 AI 0
20 AI 1
21 AI 2
22 AI 3
23 AI 4
24 AI 5
25 AI 6
26 AI 7
27 NR (AI SENSE)
28 No connect
29 No connect
30 No connect
31 No connect
32 No connect
33 No connect
34 No connect
35 No connect
36 ID 0
Table 9. USB-6451 AI Connector Signal Descriptions
Signal Function Reference Direction Description
AI <0..7> Analog input channels Varies Input

Supports differential or single-ended measurement modes. The default configuration is differential mode.

In differential mode, these channels are the positive input for the differential pair. The negative input of the differential pair is located directly beneath the positive input.

In single-ended mode, each signal is a separate analog input voltage channel. The ground reference in single-ended mode is configurable. In referenced single-ended (RSE) mode, AI GND is the reference for the voltage measurement. In non-referenced single-ended (NRSE) mode, the NR pin is the reference.

Note You can configure the input mode per channel.
AI <8..15> Analog input channels Varies Input

Supports single-ended measurements only. The default configuration is RSE mode. In RSE mode, AI GND is the reference for the voltage measurement. In NRSE mode, the NR pin is the reference.

For differential measurements, refer to the descriptions for AI <0..7>.
AI GND Analog input ground — — The reference point for single-ended measurements in RSE mode and the bias current return point for differential measurements.

AI GND, AO GND, D GND, and CHSGND are all connected internally.
NR (AI SENSE) AI SENSE for NRSE mode — Input The AI SENSE pin is labeled "NR" because it is used when the input terminal is configured to NRSE mode. In NRSE mode, AI SENSE acts as a remote sense of a reference voltage that can be at a different voltage potential than AI GND.
CHSGND Chassis ground — — Connects directly to the chassis ground of the USB-6451 enclosure. It can be used as a termination point for shielded cables to help improve measurement quality.
ID 0 — — — This feature is not supported yet.

USB-6451 AO/DIO Connector Pinout

Use the pinout to connect to analog output and digital input/output terminals on the USB-6451.

Figure 8. USB-6451 AO/DIO Connector Pinout


Table 10. USB-6451 AO/DIO Connector Pin Assignments
Pin Signal
1 CHSGND
2 AO GND
3 AO GND
4 AO GND
5 AO GND
6 D GND
7 D GND
8 PFI 8/P0.8 (port0/line8)
9 PFI 9/P0.9 (port0/line9)
10 D GND
11 PFI 10/P0.10 (port0/line10)
12 PFI 11/P0.11 (port0/line11)
13 D GND
14 PFI 12/P0.12 (port0/line12)
15 PFI 13/P0.13 (port0/line13)
16 D GND
17 PFI 14/P0.14 (port0/line14)
18 PFI 15/P0.15 (port0/line15)
19 ID 1
20 AO 0
21 AO 1
22 No connect
23 No connect
24 +5 V
25 PFI 0/P0.0 (port0/line0)
26 PFI 1/P0.1 (port0/line1)
27 D GND
28 PFI 2/P0.2 (port0/line2)
29 PFI 3/P0.3 (port0/line3)
30 D GND
31 PFI 4/P0.4 (port0/line4)
32 PFI 5/P0.5 (port0/line5)
33 D GND
34 PFI 6/P0.6 (port0/line6)
35 PFI 7/P0.7 (port0/line7)
36 D GND
Table 11. USB-6451 AO/DIO Connector Signal Descriptions
Signal Function Reference Direction Description
AO <0..1> Analog output channels AO GND Output Supplies the voltage output of the AO channels.
AO GND Analog output ground — — AO GND is the reference for the AO channels.

AI GND, AO GND, D GND, and CHSGND are all connected internally.

+5 V +5 V power source D GND Output Provides current limited +5 V power output that can be used to power external circuitry. Refer to the +5 V Power Source section for more information. Leave this pin open if you do not use it.
PFI <0..15>/P0.<0..15> Port 0 digital I/O channels D GND Input or output

Digital channels that can be individually configured as input or output.

These channels are referred to as port0/line0:15 in software when used as digital I/O. They are referred to as PFI 0:15 when used for other purposes, like timing I/O.

Can also be individually configured for the following uses.

  • Digital I/O
  • Counter/timer input
  • Counter/timer output
  • External timing or trigger signal input for AI, AO, DI, DO, counter, or timers
  • Timing or trigger signal output from AI, AO, DI, DO, counter, or timers
D GND Digital ground — — Supplies the reference for the P0.<0..15> pins and +5 V pin.

AI GND, AO GND, D GND, and CHSGND are all connected internally.
CHSGND Chassis ground — — Connects directly to the chassis ground of the USB-6451 enclosure. It can be used as a termination point for shielded cables to help improve measurement quality.
ID 1 — — — This feature is not supported yet.