Mechatronics, Industrial Control & Instrumentation

The USB-6009 Data Acquisition Card Features

The USB-6009 is a small external data acquisition and control device manufactured by National Instruments that is normally connected to a computer through a USB port. It is used in applications such as simple data logging, academic lab experiments and portable measurements. This device has analogue to digital (A/D) conversion capabilities as well as digital to analogue (D/A) conversion, digital I/O, and counters/timers.

Fig: The USB-6009 data acquisition device.

The I/O lines are connected with wire (16-28 AWG) to the detachable screw terminals. As indicated in the tables 1.0, 1.1 and 1.2 below, screw terminals 1-16 are used for analog I/O, and terminals 17-32 are used for digital I/O and counter/timer functions.

Take note of the fact, analog terminals are different depending on which mode the device is in: single-ended mode (also referred to as RSE) or differential mode. In single-ended mode the positive voltage signal is connected to an AI terminal and the negative voltage or ground signal is connected to a GND terminal. This mode utilizes two terminals, implying that they are eight analog inputs available (AI 0 – AI 7). There are two analog outputs AO 0 and AO 1. The maximum voltage range in this mode is -10 V to 10 V.

Differential mode can be used to get a larger voltage range. This mode measures the difference between two signals, AI+ and AI-, each referenced to GND. A voltage range of -20 V to 20 V can be attained, however the maximum voltage on one pin (AI+ or AI-) referenced to ground is ±10 V. Differential mode uses one more wire than single-ended mode, thus only four analog inputs are available in this mode. One more difference between differential and single-ended mode is the resolution of the analog inputs. Differential mode has a resolution of 14 bits where single-ended mode has a resolution of 13 bits.

Table 1.0: USB-6009 Pin Assignments, Analog (1-16)

Terminal	Signal (Single-Ended Mode)	Signal (Differential Mode)
1	GND	GND
2	AI 0	AI 0+
3	AI 4	AI 0-
4	GND	GND
5	AI 1	AI 1+
6	AI 5	AI 1-
7	GND	GND
8	AI 2	AI 2+
9	AI 6	AI 2-
10	GND	GND
11	AI 3	AI 3+
12	AI 7	AI 3-
13	GND	GND
14	AO 0	AO 0
15	AO 1	AO 1
16	GND	GND

Table 1.1: USB-6009 Pin Assignments, Digital (17-32)

Terminal	Signal
17	P0.0
18	P0.1
19	P0.2
20	P0.3
21	P0.4
22	P0.5
23	P0.6
24	P0.7
25	P1.0
26	P1.1
27	P1.2
28	P1.3
29	PFI 0
30	+2.5 V
31	+5 V
32	GND

The analog input converter type is successive approximation and the maximum sampling rate is 48 thousand samples per second (kS/s). This device contains one analog-to-digital converter that is multiplexed to each input. Lastly this device supports USB 2.0 full-speed interface.

Table 1.2: USB-6009 Pin Signal Descriptions

Signal Name	Reference	Direction	Description
GND	–	–	Ground – The reference point for single-ended AI measurements, bias current return point for differential mode measurements, AO voltages, digital signals at the I/O connector, +5 VDC supply and the +2.5 VDC reference.
AI<0..7>	Varies	Input	Analog Input Channels 0 to 7 – For single-ended measurements, each signal is an analog input voltage channel. For differential measurements, AI 0 and AI 4 are the positive and negative inputs of differential analog input channel 0. The following signal pairs also form differential input channels: <AI 1, AI 5>, <AI 2, AI 6>, and <AI 3, AI 7>.
AO 0	GND	Output	Analog Channel 0 Output – Supplies the voltage output of AO channel 0.
AO 1	GND	Output	Analog Channel 1 Output – Supplies the voltage output of AO channel 1.
P1.<0..3> P0.<0..7>	GND	Input or Output	Digital I/O signals – You can individually configure each signal as input or output.
+2.5 V	GND	Output	+2.5 V External Reference – Provides a reference for wrap-back testing.
+5 V	GND	Output	+5 V Power Source – Provides +5V power up to 200 mA.
PFI 0	GND	Input	PFI 0 – This pin is configurable as either a digital trigger or an event counter input.

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John Mulindi

John Mulindi is an Industrial Instrumentation and Control Professional with a wide range of experience in electrical and electronics, process measurement, control systems and automation. In free time he spends time reading, taking adventure walks and watching football.