Transcript introduction to LabJack

ECE 101
Exploring Electrical Engineering
Chapter 11
LabJack Introduction
Herbert G. Mayer, PSU
Status 11/30/2015
Taken with permission from PSU Prof. Phillip Wong
Syllabus
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LabJack HW Overview
LabJack Features
LabJack HW Control
Input & Output Channels
Digital Input Output
Analog Input
Analog Output
LabJack HW Overview
The LabJack U3 is a
basic external DAQ
unit that is used to
interface a computer
to the physical world.
Company website:
http://labjack.com
General tech support: http://labjack.com/support
U3-specific support: http://labjack.com/u3
2
What can LabJack do?

Read the output of sensors which measure:
 voltage, current, power, temperature
 humidity, wind speed, force, pressure, strain
 acceleration, RPM, light intensity, sound intensity
 gas concentration, position, and many more
A LabJack brings this data into a computer where it can
be stored and processed.

Control things like motors, lights, solenoids, relays,
valves, and more.
3
LabJack Features
Model U3-LV (Low Voltage)
• 16 flexible I/O (digital input, digital output, or analog input)
• Up to 16 12-bit analog inputs (0 → 2.4 V or 0 → 3.6 V, SE or Diff)
• Maximum input stream rate of 2.5 → 50 kHz
• 2 analog outputs (10-bit, 0-5 V, 16 Hz)
• 4 additional digital I/O
• Up to 2 timers (pulse timing, PWM output, quadrature input)
• Up to 2 counters (32 bit each)
• USB 2.0/1.1 interface → Connect to computer via USB cable
• Windows, Linux, Mac drivers
Model U3-HV (High Voltage)
• First 4 FIO are replaced by dedicated HV analog inputs
• The HV inputs have ±10 V or -10/+20 V range
4
Model U3-LV Pinouts:
Model U3-HV Pinouts:
USB Port
USB Port
VS = +5 V DC
GND = ground
SGND
SPC
SGND
VS
VS
GND
DAC0
DAC1
FIO7
FIO6
GND
VS
VS
GND
FIO2
FIO3
FIO5
FIO4
GND
VS
VS
GND
FIO0
FIO1
DB15 Port
FIOxx
= flexible I/O
AINx
= analog input
DACx
= analog output
SGND
SPC
SGND
VS
VS
GND
DAC0
DAC1
FIO7
FIO6
GND
VS
VS
GND
AIN2
AIN3
FIO5
FIO4
GND
VS
VS
GND
AIN0
AIN1
DB15 Port
5
DB15 & USB Ports
EIO6
GND
8
EIO2
EIO4
7
15
6
14
EIO0
5
13
EIO5
EIO7
CIO3
4
12
CIO1
3
11
EIO1
EIO3
VS
2
10
1
9
DB15
(EIO & CIO)
CIO2
GND
screw
terminals
CIO0
DB15 Female Connector Pinout
VS = +5 V DC
GND = ground
EIOxx = 8 flexible I/O
CIOx = 4 dedicated digital I/O
USB
(type B)
status LED
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LabJack HW Control
 LabJack company-supplied software
Windows configuration utility: LJControlPanel
 3rd party software
e.g., DAQFactory Express
 User developed software
Supported languages include:
C/C++, VC6, .NET, Java
 Python, VB6, PureBasic
 MATLAB
 LabVIEW, VEE

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Ground & VS
 GND is an electrical
ground point.
(USB → PC → AC mains)
 VS is a fixed +5 V DC
output voltage.
These can be used to
power external circuits.
Maximum current: 450 mA
SGND
SPC
SGND
VS
VS
GND
DAC0
DAC1
FIO7
FIO6
GND
VS
VS
GND
FIO2
FIO3
FIO5
FIO4
GND
VS
VS
GND
FIO0
FIO1
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Input & Output Channels

An I/O channel is a hardware circuit inside the
LabJack that can
 Sense an input signal
 Generate an output signal

Supported signals:
 Digital (binary levels)
 Analog (continuous levels)
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LabJack Channels (U3-LV model)

FIO (16: FIO0-FIO7 terminals
EIO0-EIO7 DB15)


DAC (2: DAC0-DAC1 terminals)


Flexible - can be any one
of the following:
 Digital input or output
 Analog input
 Timer
 Counter
Analog output only
CIO (4: CIO-CIO3 DB15)

SGND
SPC
SGND
VS
VS
GND
DAC0
DAC1
FIO7
FIO6
GND
VS
VS
GND
FIO2
FIO3
FIO5
FIO4
GND
VS
VS
GND
FIO0
FIO1
Digital input or output only
10
Digital Input Output

Input → Sense a low or high input voltage
+3.3 V
100K Ω
Maximum Input Limit
FIO: -10 V to +10 V
EIO: -6 V to +6 V

Sense
Output-Low → Force a low output voltage
FIO: R = 550 Ω
EIO/CIO: R = 180 Ω

Sense: 0 = Low, 1 = High
R
GND
Output = 0 V
Output-High → Force a high output voltage
FIO: R = 550 Ω
EIO/CIO: R = 180 Ω
R
+3.3 V
Output = +3.3 V (no load)
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Analog Input

Single-ended
 One analog input is required
 Input voltage is measured with respect to ground
Maximum Input Limit
FIO: -10 V to +10 V
EIO: -6 V to +6 V

Input
AINx
Ground
GND
Sense: 0 to +2.44
Input values < 0 V are reported as 0 V.
Input values > +2.44 V are reported as +2.44 V
Differential
 Two analog inputs are required
Input
AINx
Reference
AINy
 The voltage difference between the input and the
reference is measured (i.e., VInput – VReference)
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Analog Input Sampling Modes
 Command/Response (Software based timing)
Program initiates an input request
 LabJack measures a single sample
 Program reads the sample data value
 Easy to set up but slow sampling rate

 Stream (Hardware based timing)
Program initiates an input request
 LabJack hardware continuously samples the input
 Program reads an entire block of sample data
 Complicated to set up but fast sampling rate

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Analog Output


The DAC can generate an output voltage with a
specified amplitude (within limits).
DACx
Output
GND
Ground
Output Range
DAC: +0.04 V to +4.95 V
The output filter limits the output sampling rate to
approximately 16 Hz.
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Timer & Counter

The timer is for applications that require accurate
hardware-based timing.
Timer

In PWM mode, the timer generates a
pulse width modulated output signal.
FIO
A counter accumulates the number of falling edges (Hto-L signal transition) detected on an FIO.
1
2
3
FIO
Counter (32-bit register)
00000000000000000000000000000011
= 310
This keeps track of
the number of
times an event has
occurred.
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Summary
Screw Terminals
• FIO (8: FIO0-FIO7)
• Digital input (-10 V to +10 V)
• Digital output (L: 0 V, H: +3.3 V)
• Analog input (-10 V to +10 V)
[Usable range: 0 V to +2.44 V]
• Timer / Counter
• DAC (2: DAC0-DAC1)
• Analog output (0 V to +4.95 V)
• VS (6)
• Fixed DC voltage (+5 V)
• GND (5)
• Ground reference (0 V)
DB15 Port
• EIO (8: EIO0-EIO7)
• Digital input (-6 V to +6 V)
• Digital output (L: 0 V, H: +3.3 V)
• Analog input (-6 V to +6 V)
[Usable range: 0 V to +2.44 V]
• Timer / Counter
• CIO (4: CIO0-CIO3)
• Digital input (-6 V to +6 V)
• Digital output (L: 0 V, H: +3.3 V)
• VS (1)
• Fixed DC voltage (+5 V)
• GND (2)
• Ground reference (0 V)
Warnings
• Do not exceed rated voltage limits for inputs.
• Never apply an external voltage into an output.
• Do not short-circuit the LabJack.
• Do not overtighten screw terminals.
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REFERENCE: I/O Specifications
The following tables contain more detailed
specifications for the LabJack's hardware.
VS Parameter
Output Voltage
Maximum Current
Conditions
Min
Typ
Max
Units
Self-Powered
4.75
5.0
5.25
V
Bus-Powered
4.0
5.0
5.25
V
Self-Powered
450
mA
Bus-Powered
50
mA
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Digital I/O Parameter
Conditions
Min
Typ
Max
Units
Low Level Input Voltage
-0.3
0.8
V
High Level Input Voltage
2
5.8
V
FIO
-10
10
V
EIO/CIO
-6
6
V
Maximum Input Voltage
Output Low Voltage
No Load
0
V
FIO
Sinking 1 mA
0.55
V
EIO/CIO
Sinking 1 mA
0.18
V
EIO/CIO
Sinking 5 mA
0.9
V
No Load
3.3
V
FIO
Sourcing 1 mA
2.75
V
EIO/CIO
Sourcing 1 mA
3.12
V
EIO/CIO
Sourcing 5 mA
2.4
V
FIO
6
mA
EIO/CIO
18
mA
FIO
550
Ω
EIO/CIO
180
Ω
Output High Voltage
Short Circuit Current
Output Impedance
18
Analog Input Parameter
Max
Units
0
2.44
V
Differential, LV
-2.44
2.44
V
Special, LV
0
3.6
V
Max AIN Voltage to GND
Valid Readings, LV
-0.3
3.6
V
Max AIN Voltage to GND
No Damage, FIO
-10
10
V
No Damage, EIO
-6
6
V
Typical Input Range
Conditions
Min
Single-Ended, LV
Resolution
Integral Linearity Error
Differential Linearity Error
Typ
12
bits
±0.05
% FS
±1
counts
Effective Resolution (RMS)
QuickSample Off
>12
bits
Noise-free Resolution
QuickSample Off
11.0
bits
Single-Ended, LV
1.2
mV
Diff., Special, LV
2.4
mV
LV
40
MΩ
Input Impedance
Source Impedance
LongSettling Off, LV
10
kΩ
LongSettling On, LV
200
kΩ
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Analog Output Parameter
Nominal Output Range
Conditions
Min
No Load
@ ±2.5 mA
Typ
Max
Units
0.04
4.95
V
0.225
4.775
V
Slew Rate
0.4
V/ms
Resolution
20
bits
Absolute Accuracy
5% to 95% FS
±5.0
% FS
Short Circuit Current
Max to GND
45
mA
50
Ω
Source Impedance
Output frequency
Sinusoidal
16
Hz
20
Timer & Counter Modes
Mode
Description
Mode
Description
0
16-bit PWM output
7
Frequency output
1
8-bit PWM output
8
Quadrature input
2
Period input (32-bit, rising edges)
9
Timer stop input (odd timers only)
3
Period input (32-bit, falling edges)
10
System timer low read (default)
4
Duty cycle input
11
System timer high read
5
Firmware counter input
12
Period input (16-bit, rising edges)
6
Firmware counter input (debounced)
13
Period input (16-bit, falling edges)
Allowed channels:
FIO4-FIO7, EIO0-EIO3
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