ADLINK USB-2405 User Manual

USB-2405

USB 2.0-based Dynamic Signal Acquisition Module

User’s Manual

Manual Rev.: 2.00
Revision Date: July 5, 2013
Part No: 50-1Z148-1000

Advance Technologies; Automate the World.

Revision History

Revision Release Date Description of Change(s)

2.00 July 5, 2013 Initial release

ii

USB-2405

Preface

Copyright 2013 ADLINK Technology, Inc.

This document contains proprietary information protected by copy­right. All rights are reserved. No part of this manual may be repro­duced by any mechanical, electronic, or other means in any form
without prior written permission of the manufacturer.

Disclaimer

The information in this document is subject to change without prior
notice in order to improve reliability, design, and function and does
not represent a commitment on the part of the manufacturer.

In no event will the manufacturer be liable for direct, indirect, spe­cial, incidental, or consequential damages arising out of the use or
inability to use the product or documentation, even if advised of
the possibility of such damages.

Environmental Responsibility

ADLINK is committed to fulfill its social responsibility to global
environmental preservation through compliance with the Euro­pean Union's Restriction of Hazardous Substances (RoHS) direc­tive and Waste Electrical and Electronic Equipment (WEEE)
directive. Environmental protection is a top priority for ADLINK.
We have enforced measures to ensure that our products, manu­facturing processes, components, and raw materials have as little
impact on the environment as possible. When products are at their
end of life, our customers are encouraged to dispose of them in
accordance with the product disposal and/or recovery programs
prescribed by their nation or company.

Trademarks

Product names mentioned herein are used for identification pur­poses only and may be trademarks and/or registered trademarks
of their respective companies.

Preface iii

Conventions

Take note of the following conventions used throughout this
manual to make sure that users perform certain tasks and
instructions properly.

Additional information, aids, and tips that help users perform
tasks.

NOTE:

NOTE:

Information to prevent minor physical injury, component dam-

age, data loss, and/or program corruption when trying to com-

CAUTION:

WARNING:

plete a task.

Information to prevent serious physical injury, component

damage, data loss, and/or program corruption when trying to
complete a specific task.

iv Preface

USB-2405

Table of Contents

Revision History...................................................................... ii

Preface.................................................................................... iii

List of Figures....................................................................... vii

List of Tables.......................................................................... ix

1 Introduction ........................................................................ 1

1.1 Overview.............................................................................. 1

1.2 Features............................................................................... 1

1.3 Applications ......................................................................... 2

1.4 Specifications....................................................................... 2

1.4.1 General Specifications................................................ 2

1.4.2 Analog Input (AI)......................................................... 2

1.4.3 DC accuracy @25°C .................................................. 3

1.4.4 AC Dynamic Performance (typical, 25°C) .................. 3

1.4.5 Digital I/O.................................................................... 5

1.5 Software Support ................................................................. 5

1.6 Driver Support for Windows................................................. 6

1.7 Utilities for Windows ............................................................ 6

1.8 Overview and Dimensions ................................................... 8

1.8.1 Module........................................................................ 8

1.8.2 Module Stand ........................................................... 10

1.9 Connections....................................................................... 16

2 Getting Started ................................................................. 17

2.1 Unpacking the USB-2405 .................................................. 17

2.2 Connecting the USB-2405 Module .................................... 17

2.3 Device ID ........................................................................... 19

2.4 Device Mounting ................................................................ 20

Table of Contents v

2.4.1 Rail Mounting............................................................ 20

2.4.2 Wall Mounting ........................................................... 23

2.5 Hardware Configuration ..................................................... 25

3 Operation........................................................................... 27

3.1 Functional Layout............................................................... 27

3.2 Analog Input....................................................................... 28

3.2.1 Analog Input Front End Configuration ...................... 28

3.2.2 AI Data Format ......................................................... 29

3.2.3 Sampling Rate .......................................................... 30

3.2.4 Data Transfer............................................................ 31

3.2.5 Anti-Aliasing Filter and Frequency Response...........31

3.3 Triggering........................................................................... 33

3.3.1 Analog Input Trigger Source..................................... 33

3.4 Programmable Function I/O............................................... 39

3.4.1 Static Digital Input/Output ......................................... 39

3.4.2 Frequency Counter ................................................... 39

3.4.3 Pulse Output ............................................................. 39

3.4.4 Digital Trigger IN for Continuous Analog Input ......... 40

3.4.5 Synchronization Sample Clock IN ............................ 40

4 Calibration......................................................................... 41

4.1 Loading Calibration Constants........................................... 41

4.2 Auto-Calibration ................................................................. 41

4.3 Saving Calibration Constants............................................. 42

Important Safety Instructions............................................... 43

Getting Service...................................................................... 45

vi Table of Contents

USB-2405

List of Figures

Figure 1-1: U-Test Interface.......................................................... 7

Figure 1-2: USB-2405 Module Front View .................................... 9

Figure 1-3: USB-2405 Module Side View ..................................... 9

Figure 1-4: USB-2405 Module Rear View................................... 10

Figure 1-5: Module, Stand, and USB Cable................................ 11

Figure 1-6: Module, Stand, & Wall Mount Kit Side View (w/ Connec-

tions)......................................................................... 12

Figure 1-7: Module In Stand Front View ..................................... 13

Figure 1-8: Module Stand Top View ........................................... 14

Figure 1-9: Module Stand Side Cutaway View ........................... 15

Figure 1-10: Module Stand Front View ......................................... 15

Figure 1-11: BNC Connector Polarity ........................................... 16

Figure 2-1: USB-2405 Module in Windows Device Manager...... 18

Figure 2-2: Device ID Selection Control...................................... 19

Figure 2-3: Rail Mount Kit ........................................................... 20

Figure 2-4: Module Pre-Rail Mounting ........................................ 21

Figure 2-5: Module Rail-Mounted ............................................... 22

Figure 2-6: Wall Mount Holes ..................................................... 23

Figure 2-7: USB-2405 Module with Wall Mount Apparatus ........ 24

Figure 3-1: USB-2405 Functional Block Diagram ....................... 27

Figure 3-2: USB-2405 Analog Front End .................................... 28

Figure 3-3: Excitation Current for IEPE Sensor Measurement ... 29
Figure 3-4: Input Frequency Response for High Resolution Mode

(Fs=51.2kS/s) ........................................................... 32

Figure 3-5: Input Frequency Response for High Speed Mode

(Fs=102.4kS/s) ......................................................... 33

Figure 3-6: Below-Low Analog Triggering................................... 34

Figure 3-7: Above-High Analog Triggering ................................. 35

Figure 3-8: Digital Triggering ...................................................... 35

Figure 3-9: Post Trigger without Retrigger.................................. 36

Figure 3-10: Pre-trigger Mode Operation (valid trigger only) ........ 36

Figure 3-11: Pre-trigger Mode Operation (w/ invalid trigger) ........ 37

Figure 3-12: Delay-Trigger Mode Operation ................................. 37

Figure 3-13: Middle-Trigger Acquisition ........................................ 38

Figure 3-14: Gated Trigger ........................................................... 38

List of Figures vii

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viii List of Figures

USB-2405

List of Tables

Table 1-1: U-Test Interface Legend.................................................. 7

Table 3-1: Signal Source-Card Configuration ................................. 28

Table 3-2: USB-2405 Input Ranges................................................ 30

List of Tables ix

This page intentionally left blank.

xList of Tables

1 Introduction

1.1 Overview

The USB-2405 is a 24-bit high-performance dynamic signal acqui­sition USB module, equipped with 4 simultaneous-sampling ana­log input channels sampling up to 128 kS/s per channel. The
USB-2405 also features software selectable AC or DC coupling
input configuration, and built-in high precision 2 mA excitation cur­rent to measure integrated electronic piezoelectric (IEPE) sensors
such as accelerometers and microphones.

The USB-2405 delivers high precision DC and dynamic measure­ment performance with very low temperature drift. The onboard
24-bit Sigma-Delta ADC supports anti-aliasing, which suppresses
modulator and signal out-of-band noise and provides usable sig­nal bandwidth of the Nyquist rate, making it ideal for high dynamic
range signal measurement in vibration and acoustic applications.

The USB-2405 supports digital and analog trigger sources and
flexible trigger modes, including post, delay, middle, gated, and
pre-triggering, which acquires data efficiently without post pro­cessing. The USB-2405 is USB bus powered and equipped with
BNC connectors and removable spring terminals for easy device
connectivity.

USB-2405

1.2 Features

X Hi-Speed USB 2.0

X USB bus powered

X 24-bit Sigma-Delta ADC with built-in anti-aliasing filter

X 4-CH simultaneous sampling analog input, up to 128kS/s

X AC or DC input coupling, software selectable

X Analog or digital triggering

X Supports 2mA excitation output on each analog input chan-

nel for IEPE sensor measurement

X Full auto-calibration

X Ready-to-use testing application (U-Test) provided

Introduction 1

1.3 Applications

X Vibration testing

X Machine condition monitoring

X Acoustic measurement

X Environmental noise analysis

1.4 Specifications

1.4.1 General Specifications

Physical, Power, and Operating Environment

Interface Hi Speed USB 2.0 compatible, mini-USB connector

Dimensions 156.5 (L) x 114 (W) x 41.3 (H) mm (6.16 X 4.49 X

1.63 in.)

I/O Connector Four BNC connectors and 4-pin removable spring

terminals

Power requirement USB power (5 V @ 400 mA)

Operating environment Ambient temperature: 0 to 55°C

Relative humidity: 10% to 90%, non-condensing

Storage environment Ambient temperature: -20 to 70 °C

Relative humidity: 5% to 95%, non-condensing

1.4.2 Analog Input (AI)

Channels 4 (simultaneous-sampling)

ADC resolution 24-bit

ADC type Delta-sigma

Sampling rate 1kHz to 128kHz

Input range ±10V

FIFO buffer size 8kS across all channel

Input configuration Differential or pseudo-differential

Input impedance 200 kΩ between positive input and

negative input

16.93 kΩ between negative input and
chassis ground

Input coupling AC or DC, software selectable

2Introduction

USB-2405

Integrated electronic piezoelectric
(IEPE)

Over-voltage protection ±60V

Input common mode range ±10V

Trigger source Analog or digital, software selectable

Trigger mode Post trigger, delay trigger, middle

Data transfer Programmed I/O, continuous (bulk

Current: 2 mA or 0 mA, software
selectable
IEPE compliance: 24V

trigger, gated trigger, pre-trigger, post
or delay trigger with re-triggering

transfer mode)

1.4.3 DC accuracy @25°C

Offset Error (mV) Gain Error (%)

Typical ±0.15mV ±0.15mV

Maximum ±0.3mV ±0.3%

1.4.4 AC Dynamic Performance (typical, 25°C)

THD, THD+N (Vin = 8.9 Vpk)

Input Configuration

Differential 20Hz to 20kHz -94dB -91 dB

Pseudo-differential 20Hz to 20kHz -92 dB -88 dB

Input Signal
Frequency (fin)

20Hz to 46.4kHz -89 dB -88 dB

20Hz to 46.4kHz -85 dB -85 dB

THD THD+N

CMRR

AC (20Hz to 1kHz) 60 dB

Introduction 3

Bandwidth

-3dB bandwidth 0.49 x fs (where fs is sampling rate)

AC cut-off frequency (-3dB) 0.4 Hz

AC cut-off frequency (-0.1dB) 2.4 Hz

Flatness

Input Signal Frequency (fin)

20Hz to 20kHz ±0.01 dB

20Hz to 46.4kHz ±0.15 dB

Flatness

Crosstalk

Input Signal Frequency (fin)

1kHz -102 dB

46.4kHz -95 dB

Crosstalk

System Noise

Measurement Bandwidth AI Noise

High Resolution (< 52.734kHz)

High Speed Mode (52.734 kHz to 128kHz)

SFDR (Vin = -1 dBFS)

Input Signal Frequency (fin)

1kHz 104 dB

SFDR

50

65

µVrms

µVrms

Dynamic Range (Vin = -60 dBFS)

Input Signal Frequency (fin)

1kHz 100 dB

4Introduction

Dynamic
Range

1.4.5 Digital I/O

Channels 2 programmable function I/O

Compatibility 3.3V / TTL (single-ended)

Initial status Input (pulled low)

Input voltage Logic low: VIL = 0.8 V max; IIL = 0.2 mA max.

Logic high: VIH = 2.0 V min.; IIH = 0.2 mA max.

Output voltage Logic low: VOL = 0.8 V max; IIL = 0.2 mA max.

Logic high: VOH = 2.0 V min.; IIH = 24 mA max.

Over-voltage
protection

Supporting
modes (only
one can be
selected and
function at a
time, see
Section 3.4:
Programmable
Function I/O

Data Transfer Programmed I/O

-2V to +7V

• Static digital input/output

• PWM output, max. frequency: 4 MHz

• Frequency/Event counter, max.
frequency: 4MHz

• Digital trigger IN

• Synchronization sample clock IN, max.
frequency: 128kHz

USB-2405

1.5 Software Support

ADLINK provides comprehensive software drivers and packages
to suit various user approaches to system building. In addition to
programming libraries, such as DLLs, for most Windows-based
systems, ADLINK also provides drivers for application environ­ments such as LabVIEW® and MATLAB®. ADLINK also provide
ActiveXcomponent ware for measurement and SCADA/HMI, and
breakthrough proprietary software. All software options are
included in the ADLINK All-in-One CD.

Be sure to install the driver & utility before using the USB-2405
module.

Introduction 5

1.6 Driver Support for Windows

UD-DASK

UD-DASK is composed of advanced 32/64-bit kernel drivers for
customized DAQ application development. USB-DASK enables
you to perform detailed operations and achieve superior perfor­mance and reliability from your data acquisition system. DASK
kernel drivers now support Windows 7/Vista
only UD-DASK versions 1.2.2.0627 and later can support the
USB-2405 module.

®

OS. Please note that

DAQPilot

DAQPilot is a task-oriented Software Development Kit, supporting
ActiveX Controls/.NET Assembly, Express VI and Polymorphic VI
for LabVIEW and DAQ Toolbox for MATLAB.

You can download and install DAQPilot at:

http://www.adlinktech.com/TM/DAQPilot.html

Please note that only DAQPilot versions 2.6.1.0628 and later can
support the USB-2405.

1.7 Utilities for Windows

U-Test

U-Test is a free and ready-to-use utility which can assist instant
testing and operation of all ADLINK USB DAQ series functions
with no programming. In addition to providing data collection and
monitoring functions, U-Test also supports basic FFT analysis and
provides direct control of analog output and digital I/O with a
user-friendly interface.

6Introduction

USB-2405

A

B

C

D

Figure 1-1: U-Test Interface

A Main Menu

B Device Viewer

C AI Data View & AO, DIO Control Panel

D Analog Input Configuration

Table 1-1: U-Test Interface Legend

You can download and install U-Test at: http://www.adlink­tech.com/

Introduction 7

1.8 Overview and Dimensions

All dimensions shown are in millimeters (mm)

NOTE:

NOTE:

1.8.1 Module

41.3

45.6

8Introduction

Figure 1-2: USB-2405 Module Front View

156.5

167.5

USB-2405

114

Figure 1-3: USB-2405 Module Side View

Introduction 9

Figure 1-4: USB-2405 Module Rear View

1.8.2 Module Stand

The multi-function USB-2405 stand is compatible with desk, rail, or
wall mounting. To fix the module in the stand, slide the module
body into the stand until a click is heard. To remove the module

10 Introduction

USB-2405

from the stand, twist the bottom of the stand in a back-and forth
motion and separate from the module.

Figure 1-5: Module, Stand, and USB Cable

Introduction 11

128

167
198

Figure 1-6: Module, Stand, & Wall Mount Kit Side View (w/ Connections)

12 Introduction

USB-2405

114

100

Figure 1-7: Module In Stand Front View

Introduction 13

26

B

20.4

Figure 1-8: Module Stand Top View

14 Introduction

20.4

1.5

3.4

6

USB-2405

5.89

Figure 1-9: Module Stand Side Cutaway View

100

Figure 1-10: Module Stand Front View

Introduction 15

1.9 Connections

The USB-2405 module is equipped with four BNC connectors and
one 4-pin removable spring terminal connector, with pin assign­ment as labeled.

BNC connector polarity is as shown.

Positive (+)

Negative (-)

Figure 1-11: BNC Connector Polarity

16 Introduction

2 Getting Started

2.1 Unpacking the USB-2405

Before unpacking, check the shipping carton for any damage. If the
shipping
immediately.
inspection.
any
included

2.2 Connecting the USB-2405 Module

carton and/or contents are damaged, inform your dealer

Retain the shipping carton and packing materials for

Obtain authorization from your dealer before returning

product to ADLINK. Ensure that the following items are

in

the package.

Z USB-2405

Z Stand

Z USB cable (2 meter)

Z Rail mount kit

Z ADLINK All-in-One CD

Z Quick Start Guide

USB-2405

The appropriate driver must be installed before you can con­nect the USB DAQ to the computer system. Refer to

WARNING:

Section 1.6: Driver Support for Windows for driver support
information.

1. Turn on the computer.

2. Connect the USB-2405 module to one USB 2.0 port on
the computer using the included USB cable.

3. The first time the USB-2405 module is connected, a New
Hardware message appears. It will take around 6 sec­onds to load the firmware. When loading is complete, the
LED indicator on the rear of the USB DAQ module

Getting Started 17

changes from amber to green and the New Hardware
message closes.

4. The USB-2405 module can now be located in the hard­ware Device Manager, as shown.

Figure 2-1: USB-2405 Module in Windows Device Manager

If the USB-2405 module cannot be detected, the power provided
by the USB port may be insufficient. The USB-2405 module is
exclusively powered by the USB port and requires 400 mA @ 5 V.

18 Getting Started

USB-2405

2.3 Device ID

A rotary control on the rear of the module (as shown) controls
device ID setting and can be set from 0 to 7. The device ID allows
dedicated control of the USB-2405 module irrespective of the con­nected USB port. When more than one USB module of the same
type is connected, each must be set to a different ID to avoid con­flicts and errors in operation.

Figure 2-2: Device ID Selection Control

Getting Started 19

2.4 Device Mounting

2.4.1 Rail Mounting

The multi-function stand can be mounted on the DIN rail using the
rail-mount kit as shown.

Figure 2-3: Rail Mount Kit

20 Getting Started

USB-2405

Figure 2-4: Module Pre-Rail Mounting

Getting Started 21

Figure 2-5: Module Rail-Mounted

22 Getting Started

USB-2405

2.4.2 Wall Mounting

The multi-function stand can be fixed to a wall using four flush
head screws as shown. The four screw holes should be
approximately 3.4 mm in diameter.

Figure 2-6: Wall Mount Holes

Getting Started 23

Figure 2-7: USB-2405 Module with Wall Mount Apparatus

24 Getting Started

USB-2405

2.5 Hardware Configuration

All remaining hardware configurations are software
programmable, including sampling/update rate, input/output
channel, input range, and others. Please see the UD-DASK
Function Reference manual for details.

Getting Started 25

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26 Getting Started

3 Operation

Operation of the USB-2405 is described here to assist in
configuration and programming of the module. Functions
addressed include analog input and GPIO.

3.1 Functional Layout

The USB-2405 is equipped with four simultaneous-sampling
analog input channels and two general-purpose digital I/Os
(GPIO).

EEPROM

Control Signal

EEPROM

USB-2405

4-CH AI

2-CH GPIO

ADC Front end

24 Bit Sigma-

delta ADC

AFI

GPIO Circuit

DI, DO,

Counter,

PWM OUT,

Trigger IN

DDS (Direct

Digital

Synthesis)

AI Data and Control

I2C Interface

GPIO

ADLINK

FPGA

AI

Calibration

Control

Calibration

data

A/D

Others

function

8051 Core

3.3 2.5 1.2V
Supply

Cypress

CY7C68013A

8051 Core 12/24/

DDR2 SDRAM

DATA

24MHz XTAL

Power
circuit

Figure 3-1: USB-2405 Functional Block Diagram

48MHz

3.3V Supply

USB BUS

+5V Supply

USB INTERFACE

Operation 27

3.2 Analog Input

3.2.1 Analog Input Front End Configuration

AI

Calibration

Circuit

Differential/

Psuedo-

differential

Switch
Circuit

IEPE

Circuit

AC

Coupling

circuit

ADC Driver

Diff input

24 Bit ADC

Figure 3-2: USB-2405 Analog Front End

Input Configuration: Differential/Pseudo-Differential

Differential input mode provides anode and cathode inputs of the
BNC connector that respond to signal voltage differences
therebetween. If the signal source is ground-referenced, the
differential input mode can be used for common-mode noise
rejection.

If the signal source is a floating signal, setting pseudo-differential
input mode will provide a reference ground connected to the
cathode input of the BNC through a 20 kΩ resistor.

Recommended configurations for the signal sources are as
follows.

Signal Source Card Configuration

Floating Pseudo-differential

Ground-reference Differential

Table 3-1: Signal Source-Card Configuration

Input Coupling

When DC coupling is selected, DC offset present in the input sig­nal is passed to ADC. DC coupling configuration is indicated when
the signal source has a small offset voltage or if the DC content of

28 Operation

USB-2405

the signal is important. When AC coupling is selected, DC offset
present in the input signal is removed. AC coupling configuration
is indicated when the DC content of the input signals is to be
rejected. AC coupling enables a high pass R-C filter through the
input signal path, with corner frequency (-3dB) about 0.4 Hz.

IEPE Input

For applications utilizing sensors such as accelerometers or
microphones, the USB-2405 provides an excitation current
source.

The excitation current is 2 mA for the IEPE sensors, with DC volt­age offset generated because of the excitation current and sensor
impedance. When enabling IEPE current sources, the USB-2405
automatically sets input configuration to AC coupling.

VCC

2mA

Constant

Current

IEPE ON/

AI Channel

Figure 3-3: Excitation Current for IEPE Sensor Measurement

OFF

3.2.2 AI Data Format

When an A/D converter is used, properties of the signal to be
measured must be ascertained to determine the channel to be

Operation 29

used and connections to the card. After A/D conversion, the A/D
data is buffered in a Data FIFO, for transfer to memory for further
processing. Transfer characteristics of various input ranges of the
USB-2405 are as follows, with data format 2’s complement.

Description

Full-scale Range ±10V

Least significant bit 1.19uV

FSR-1LSB 9.99999881V 7FFFFFh

Midscale +1LSB 1.19uV 000001h

Midscale 0V 000000h

Midscale –1LSB -1.19uV FFFFFFh

-FSR -10V 800000h

Table 3-2: USB-2405 Input Ranges

Bipolar Analog
Input Range

Digital Code

3.2.3 Sampling Rate

To drive the sigma-delta ADC, an onboard timebase clock is
applied, with frequency exceeding the sampling rate, produced
from a DDS (Direct Digital Synthesis) chip. The output frequency
of the DDS chip is programmable, with excellent resolution.

DDS Timing/Sampling Rate

Mode High Resolution High Speed

Sampling Rate 1 kHz ~ 52.734 kHz 52.734 kHz ~ 128

kHz

fCLK/fDATA 512 256

DDS CLK 512kHz to

26.999808MHz

Sampling Rate
Resolution

0.0003 Hz 0.0003 Hz

13.499904 MHz to

2.768 MHz

30 Operation

USB-2405

3.2.4 Data Transfer

Software Polling Data Transfer (Non-Buffering Pro­grammed I/O)

Polling mode supports flexible timing and is suitable for retrieving
recent data without FIFO buffering latency. The USB-2405 contin­uously updates the most recently acquired data onto a data port
for specific channels. Data not retrieved in time is overwritten with
new data without notification. The UD-DASK Function Library Ref­erence provides corresponding software API details.

Continuous Acquisition Mode

Differs from software polling mode only in the generation of block
data in continuous acquisition mode without the need to consider
data overwriting or acquiring repeat data in software polling mode.
This mode is suitable for when continuous data is to be acquired in
a fixed and precise time interval. Please note the data buffer size
must be a multiple of 256 in continuous acquisition mode. The
UD-DASK Function Library Reference provides corresponding
software API details.

3.2.5 Anti-Aliasing Filter and Frequency Response

The filter limits the bandwidth of the signal path and rejects
out-of-band noise. The digital filter of the Sigma-Delta ADC sets
the overall frequency response, using multi-stage FIR topology to
provide linear phase with minimal passband ripple and high stop­band attenuation. These image frequencies, if present in the sig­nal and not externally filtered, will fold back (or alias) into the
passband, causing errors. The stopband of the ADC provides
100dB attenuation of frequencies that begin just beyond the pass­band and continue out to ADC over-sampling rate. The USB-2405
provides an anti-aliasing, low-pass, simple RC filter in front of the
ADC inputs to limit possible high amplitude out-of-band signals
and noise.

Operation 31

5

−3dB Bandwidth (Fs = 51.2KS/s)

0

−5

X: 25
Y: −2.058

−10

−15

(dB)

−20

−25

−30

−35
5 10 15 20 25

Input Signal Frequency (kHz)

Figure 3-4: Input Frequency Response for High Resolution Mode

(Fs=51.2kS/s)

32 Operation

−10

−20

(dB)

−30

−40

−50

USB-2405

−3dB Bandwidth (Fs = 102.4KS/s)

0

X: 50
Y: −2.27

−60

Figure 3-5: Input Frequency Response for High Speed Mode (Fs=102.4kS/s)

5 10 15 20 25 30 35 40 45 50 55

Input Signal Frequency (kHz)

3.3 Triggering

The USB-2405 supports flexible trigger sources and trigger modes
for analog input functionality. The trigger source can originate with
software command, external analog, or external digital signal in
continuous analog input mode. Trigger source and mode are pro­grammable by software.

3.3.1 Analog Input Trigger Source

Software Triggering

This trigger mode requires no external trigger signals. The trigger
asserts immediately following execution of the specified function
calls to begin the operation.

Operation 33

External Analog Trigger

The analog multiplexer can select one input channel as the analog
trigger source. That is, one of 4 input channels can be selected as
the analog trigger source. An external analog trigger occurs when
the analog trigger signal crosses above (above high) or below
(below low) the pre-defined voltage level. The range of trigger
level is the full-scale range of the selected input channel and the
resolution is 24-bit. In external analog trigger mode, the first
acquired data starts with a delay time of 1/(sampling rate).

Below-Low Analog Triggering

As shown, the trigger signal is generated when the input ana­log signal is less than the Low_Threshold voltage.
High_Threshold setting is not used in this triggering situation.

Figure 3-6: Below-Low Analog Triggering

Above-High Analog Triggering

As shown, the trigger signal is generated when the input ana­log signal exceeds the High_Threshold voltage.
Low_Threshold setting is not used in this triggering situation

34 Operation

USB-2405

Figure 3-7: Above-High Analog Triggering

External Digital Triggering

An external digital trigger occurs when a rising or falling edge is
detected on the digital signal connected to the GPIO pin. Trigger
polarity can be programmed using ADLINK software drivers.

Signal level of the external digital trigger signals should be
3/3V/TTL-compatible, with a minimum pulse of 20ns.

NOTE:

NOTE:

Positive-edge

(rising) trigger event

occurs

Negative-edge
(falling) trigger

event occurs

Figure 3-8: Digital Triggering

Trigger Modes

Analog input supports post, delay, middle, gate, post trigger with
retrigger, and delay trigger with retrigger modes.

Operation 35

Post-Trigger Acquisition Mode (no retrigger)

Post-trigger acquisition is indicated in applications where data
is to be collected after a trigger event, as shown.

Trigger

ƔOperation

start

ƔTrigger Event Occurs
ƔAcquisition start

N samplesData

ƔAcquisition stop
ƔBegin to transfer data to system

Figure 3-9: Post Trigger without Retrigger

Pre-trigger Acquisition (no retrigger)

Collects data before the trigger event, with acquisition starting
once specified function calls are executed to begin the pre-trig­ger operation, and stopping when the trigger event occurs. If
the trigger event occurs after the specified amount of data has
been acquired, the system stores only data preceding the trig­ger event by a specified amount, as shown. Note that N must
be equal to or less than 8k samples for all analog input chan­nels.

ƔTrigger Event Occurs

ƔOperation start
ƔAcquisition start

ƔAcquisition stop
ƔBegin to transfer data to

system

Time

Time

Trigger

Data

This data is

discarded.

N samples

Only acquired N

samples will be

transferred back to

system.

Figure 3-10: Pre-trigger Mode Operation (valid trigger only)

36 Operation

USB-2405

The trigger event occurs after the specified amount of data has
been acquired. However, if the trigger event occurs before the
specified amount of data has been acquired, the acquisition
engine ignores the trigger signal until the specified amount of
data has been acquired, as shown.

ƔOperation start
ƔAcquisition start

Trigger

Data

ƔTrigger signals that occur before
the specified amount of data has
been acquired are ignored

X samples have been acquired
before trigger occurs, where
X<N

N samples

ƔTrigger Event Occurs
ƔAcquisition stop
ƔBegin to transfer data to system

Figure 3-11: Pre-trigger Mode Operation (w/ invalid trigger)

Delay-Trigger Acquisition (no retrigger)

Delays data collection after the trigger event, as shown. The delay
count is specified by a 32-bit counter value, such that the maxi­mum delay count is (2

ƔOperation
start

ƔTrigger Event
Occurs

32

-1) when the minimum delay count is 1.

ƔAcquisition start

Delay Time

ƔAcquisition stop
ƔBegin to transfer data

to system

Time

Time

Trigger

Data

N samples

Figure 3-12: Delay-Trigger Mode Operation

Middle-Trigge r Ac quisition

Middle-trigger acquisition is indicated when data is to be collected
before and after the trigger event. The amount of stored data

Operation 37

before and after trigger event can be set individually (M and N
samples), as shown. Please note that M+N must be equal to or
less than 8k samples for all analog input channels, and that the
trigger event can only be accepted when the specified amount of
data has been acquired (M samples), otherwise the trigger event
will be ignored.

ƔTrigger Event Occurs
ƔAcquisition stop
ƔBegin to transfer data to

system

Trigger

Data

ƔOperation start
ƔAcquisition start

This data is

discarded.

N samples

Only acquired N

samples will be

transferred back to

system.

Figure 3-13: Middle-Trigger Acquisition

Gated Trigger

Gated-trigger acquisition is indicated in applications where data is
to be collected when trigger events are set to level high/low, and
acquisition suspended when trigger events are set to the opposite
level. The process repeats until the specified amount of data is
acquired.

Time

ƔOperation start
ƔAcquisition start

ƔTrigger event occurs

(high active)

ƔTrigger event occurs

(high active)

Time

Trigger

ƔƔƔƔ

Data N samplesM samples

Figure 3-14: Gated Trigger

Post-Trigger or Delay-Trigger Acquisition with Re-Trigger

Post-trigger or delay-trigger acquisition with re-trigger function is
indicated in applications where data is to be collected after several
trigger events. The number of scans after each trigger and the

38 Operation

USB-2405

re-trigger number are valid from 1 to the buffer size allocated in
kernel space. The process repeats until the specified amount of
re-trigger signals is detected.

3.4 Programmable Function I/O

The USB-2405 supports powerful programmable I/O function pro­vided by an FPGA chip, configurable as static digital input/output,
32-bit frequency counters, pulse output, synchronization sample
clock IN, and trigger IN. These signals are single-ended and 3.3 V/
TTL-compliant.

3.4.1 Static Digital Input/Output

Programmable function I/O can be used as static digital inputs or
outputs, with I/O lines readable and writeable by software polling,
with sample and update rate fully controlled by software timing.

3.4.2 Frequency Counter

Calculates base clocks occurring within a period (rising edge to
rising edge or falling edge to falling edge) of the repetitive input
signal, which is then converted to frequency value. Counter polar­ity can be adjusted to rising edge active or falling edge active, with
maximum frequency measurable of 4MHz.

3.4.3 Pulse Output

The GPIO can also simulate a pulse output. By setting a varying
amount of Pulse_initial_cnt and Pulse_length_cnt, varying pulse
frequencies and duty cycles can be obtained. The maximum out­put frequency is 4MHz, as shown.

Pulse_initial_count=7 Pulse_length_count=8

Timebase

PWM OUT

Operation 39

Calculation of the pulse frequency and duty cycle is as follows.

F

F

PWM

Duty

PWM

Timebase



cntlengthPulsecntinitialPulse

____

cntlengthPulse

__

cntlengthPulsecntinitialPulse



____

3.4.4 Digital Trigger IN for Continuous Analog Input

The GPIO can be programmed as the digital trigger source for
continuous analog input acquisition. Please see External Digital
Triggering for details.

3.4.5 Synchronization Sample Clock IN

To synch multiple devices, the GPIO can be programmed as exter­nal sample clock input, with the same trigger signal and external
sample clock applicable to multiple USB-2405s to achieve more
than 4 channel synchronization without phase delay. Note the syn­chronization sample clock must be continuous, with valid fre­quency range from 1 kHz to 128 kHz.

40 Operation

4 Calibration

This chapter introduces the process of calibrating the USB-2405 to
optimize AD measurement.

4.1 Loading Calibration Constants

The USB-2405 is factory-calibrated before shipment, with associ­ated calibration constants of the TrimDACs firmware written to the
onboard EEPROM. TrimDACs firmware is the algorithm in the
FPGA. Loading calibration constants entails loading the values of
TrimDACs firmware stored in the onboard EEPROM.

ADKLINK provides a software utility that automatically reads the
calibration constants, if necessary.

Dedicated space for storing calibration constants is provided in the
EEPROM. In addition to the default bank of factory calibration con­stants, there is one user-utilization bank, allowing loading of the
TrimDACs firmware values either from the original factory calibra­tion or a subsequently-performed calibration.

Since measurement errors may vary depending on time and tem­perature, it is recommended that the USB-2405 module be cali­brated in the existing testing environment, as follows.

USB-2405

4.2 Auto-Calibration

The USB-2405 module should be warmed up for at least 15
minutes before initiating auto-calibration.

NOTE:

NOTE:

The USB-2405 auto-calibration utility measures and corrects
almost all calibration errors with no requirement for external signal
connection, reference voltage, or measurement devices. An
onboard calibration reference is provided to ensure accuracy of
auto-calibration. The reference voltage is measured in the produc­tion line by a digital potentiometer and compensated in the soft­ware. The calibration constant is stored after auto-calibration.

Calibration 41

4.3 Saving Calibration Constants

Factory-calibrated constants are permanently stored in a bank of
the onboard EEPROM and cannot be modified. When the device
is recalibrated through auto-calibration, the software stores the
new constants in a user-configurable section of the EEPROM. To
restore original factory calibration settings, the software can copy
the factory-calibrated constants to the user-configurable section of
the EEPROM. When auto-calibration is complete, the new calibra­tion constants can be saved to the user-configurable banks in the
EEPROM.

42 Calibration

USB-2405

Important Safety Instructions

For user safety, please read and follow all instructions,
WARNINGS, CAUTIONS, and NOTES marked in this manual

and on the associated equipment before handling/operating the
equipment.

X Read these safety instructions carefully.

X Keep this user’s manual for future reference.

X Read the specifications section of this manual for detailed

information on the operating environment of this equipment.

X When installing/mounting or uninstalling/removing

equipment:

Z Turn off power and unplug any power cords/cables.

X To avoid electrical shock and/or damage to equipment:

Z Keep equipment away from water or liquid sources;

Z Keep equipment away from high heat or high humidity;

Z Keep equipment properly ventilated (do not block or

cover ventilation openings);

Z Make sure to use recommended voltage and power

source settings;

Z Always install and operate equipment near an easily

accessible electrical socket-outlet;

Z Secure the power cord (do not place any object on/over

the power cord);

Z Only install/attach and operate equipment on stable

surfaces and/or recommended mountings; and,

Z If the equipment will not be used for long periods of time,

turn off and unplug the equipment from its power source.

Important Safety Instructions 43

X Never attempt to fix the equipment. Equipment should only

be serviced by qualified personnel.

A Lithium-type battery may be provided for uninterrupted, backup
or emergency power.

Risk of explosion if battery is replaced with an incorrect type;
please dispose of used batteries appropriately.

WARNING:

X Equipment must be serviced by authorized technicians

when:

Z The power cord or plug is damaged;

Z Liquid has penetrated the equipment;

Z It has been exposed to high humidity/moisture;

Z It is not functioning or does not function according to the

user’s manual;

Z It has been dropped and/or damaged; and/or,

Z It has an obvious sign of breakage.

44 Important Safety Instructions

USB-2405

Getting Service

Contact us should you require any service or assistance.

ADLINK Technology, Inc.

Address: 9F, No.166 Jian Yi Road, Zhonghe District
New Taipei City 235, Taiwan

Tel: [phone]
Fax: [phone]
Email: [e-mail]

Ampro ADLINK Technology, Inc.

Address: 5215 Hellyer Avenue, #110, San Jose, CA 95138, USA
Tel: [phone]
Toll Free: [phone] (USA only)
Fax: [phone]
Email: [e-mail]

ADLINK Technology (China) Co., Ltd.

Address: Ϟ⍋Ꮦ⌺ϰᮄᓴ∳催⾥ᡔು㢇᯹䏃 300 ো(201203)
300 Fang Chun Rd., Zhangjiang Hi-Tech Park,

Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology Beijing

Address: ࣫ҀᏖ⍋⎔Ϟഄϰ䏃 1 োⲜ߯ࡼ࡯໻ E ᑻ 801 ᅸ(100085)

Tel: [phone]
Fax: [phone]
Email: [e-mail]

ᄅקؑխࡉ೴৬ԫሁ 166 ᇆ 9 ᑔ

Pudong New Area, Shanghai, 201203 China

Rm. 801, Power Creative E, No. 1,
Shang Di East Rd., Beijing, 100085 China

ADLINK Technology Shenzhen

Address: ⏅ഇᏖቅ⾥ᡔು催ᮄϗ䘧᭄ᄫᡔᴃು

Tel: [phone]
Fax: [phone]
Email: [e-mail]

LiPPERT ADLINK Technology GmbH

Address: Hans-Thoma-Strasse 11, D-68163, Mannheim, Germany
Tel: [phone]
Fax: [phone]
Email: [e-mail]

A1 󰶀 2 ὐ C  (518057)
2F, C Block, Bldg. A1, Cyber-Tech Zone, Gao Xin Ave. Sec. 7,
High-Tech Industrial Park S., Shenzhen, 518054 China

Getting Service 45

ADLINK Technology, Inc. (French Liaison Office)

Address: 15 rue Emile Baudot, 91300 Massy CEDEX, France
Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology Japan Corporation

Address: ͱ101-0045 ᵅҀ䛑ҷ⬄⼲⬄䤯ފ⬎ 3-7-4

⼲⬄ 374 ɛɳ 4F

KANDA374 Bldg. 4F, 3-7-4 Kanda Kajicho,

Chiyoda-ku, Tokyo 101-0045, Japan
Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology, Inc. (Korean Liaison Office)

Address: 昢殾柢 昢爎割 昢爎壟 1675-12 微汾瘶捒娯 8猻

8F Mointer B/D,1675-12, Seocho-Dong, Seocho-Gu,

Seoul 137-070, Korea
Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology Singapore Pte. Ltd.

Address: 84 Genting Lane #07-02A, Cityneon Design Centre,

Singapore 349584
Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology Singapore Pte. Ltd. (Indian Liaison Office)

Address: 1st Floor, #50-56 (Between 16th/17th Cross) Margosa Plaza,

Margosa Main Road, Malleswaram, Bangalore-560055, India
Tel: [phone]
Fax: [phone]
Email: [e-mail]

ADLINK Technology, Inc. (Israeli Liaison Office)

Address: 6 Hasadna St., Kfar Saba 44424, Israel
Tel: [phone]
Fax: [phone]
Email: [e-mail]

46 Getting Service