RedLab 1208FS
USB-based
Analog and Digital I/O Module
User's Guide
Document Revision 1.5 E, April, 2014
© Copyright 2014, Meilhaus Electronic
Imprint
User’s Guide RedLab® Series
Document Revision 1.5 E
Revision Date: April 2014
Meilhau
Am Sonnenlicht 2
D-82239 Alling near Munich, Germany
http://www.meilhaus.de
© Copyright 2014 Meilhaus Electronic GmbH
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form by any means, electronic, mechanical, by photocopying, recording, or
otherwise without the prior written permission of Meilhaus Electronic GmbH.
s Electronic GmbH
Important note:
All the information included in this user’s guide were put together with utmost care and to best
knowledge. However, mistakes may not have been erased completely.
For this reason, the firm Meilhaus Electronic GmbH feels obliged to point out that they cannot be take
on neither any warranty (apart from the claims for warranty as agreed) nor legal responsibility or
liability for consequences caused by incorrect instructions.
We would appreciate it if you inform us about any possible mistakes.
The trademark Personal Measurement Device, TracerDAQ, Universal Library, InstaCal, Harsh
Environment Warranty, Measurement Computing Corporation, and the Measurement Computing logo
are either trademarks or registered trademarks of Measurement Computing Corporation.
Windows, Microsoft, and Visual Studio are either trademarks or registered trademarks of Microsoft
Corporation.
LabVIEW is a trademark of National Instruments.
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All other trademarks are the property of their respective owners.
3
Table of Contents
Preface
About this User's Guide .......................................................................................................................6
What you will learn from this user's guide .........................................................................................................6
Conventions in this user's guide .........................................................................................................................6
Where to find more information.........................................................................................................................6
Chapter 1
Introducing the RedLab 1208FS ..........................................................................................................7
RedLab 1208FS block diagram ..........................................................................................................................8
Software features................................................................................................................................................8
Connecting a RedLab 1208FS to your computer is easy....................................................................................9
Chapter 2
Installing the RedLab 1208FS ............................................................................................................10
What comes with your RedLab 1208FS shipment?..........................................................................................10
Hardware .........................................................................................................................................................................10
Additional documentation................................................................................................................................................10
Unpacking the RedLab 1208FS........................................................................................................................11
Installing the software ......................................................................................................................................11
Installing the hardware .....................................................................................................................................11
Chapter 3
Functional Details ...............................................................................................................................13
Theory of operation - analog input acquisition modes .....................................................................................13
Software paced mode.......................................................................................................................................................13
Continuous scan mode .....................................................................................................................................................13
External components ........................................................................................................................................13
USB connector.................................................................................................................................................................14
LED .................................................................................................................................................................................14
Screw terminal wiring......................................................................................................................................................14
Main connector and pin out .............................................................................................................................................16
Analog input terminals (CH0 IN - CH7 IN).....................................................................................................................17
Analog output terminals (D/A OUT 0 and D/A OUT 1)..................................................................................................19
Digital I/O terminals (Port A0 to A7, and Port B0 to B7)................................................................................................20
Power terminals ...............................................................................................................................................................21
Calibration terminal .........................................................................................................................................................21
Ground terminals .............................................................................................................................................................21
External trigger terminal..................................................................................................................................................21
SYNC terminal ................................................................................................................................................................21
Counter terminal ..............................................................................................................................................................22
Accuracy...........................................................................................................................................................22
RedLab 1208FS channel gain queue feature ....................................................................................................25
Synchronizing multiple units............................................................................................................................25
Chapter 4
Specifications......................................................................................................................................27
Analog input .....................................................................................................................................................27
Analog output ...................................................................................................................................................29
Digital input/output...........................................................................................................................................29
External trigger.................................................................................................................................................30
External clock input/output...............................................................................................................................30
Counter .............................................................................................................................................................31
Non-volatile memory........................................................................................................................................31
4
RedLab 1208FS User's Guide
Microcontroller.................................................................................................................................................31
Power................................................................................................................................................................31
General .............................................................................................................................................................32
Environmental ..................................................................................................................................................32
Mechanical .......................................................................................................................................................32
Main connector and pin out..............................................................................................................................32
4-channel differential mode .............................................................................................................................................33
8-channel single-ended mode...........................................................................................................................................33
5
Preface
About this User's Guide
What you will learn from this user's guide
This user's guide explains how to install, configure, and use the RedLab 1208FS so that you get the most out of
its USB data acquisition features.
This user's guide also refers you to related documents available on our web site, and to technical support
resources.
Conventions in this user's guide
For more information on …
Text presented in a box signifies additional information and helpful hints related to the subject matter you are
reading.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
<#:#> Angle brackets that enclose numbers separated by a colon signify a range of numbers, such as those assigned
to registers, bit settings, etc.
bold text Bold text is used for the names of objects on the screen, such as buttons, text boxes, and check boxes. For
example:
1. Insert the disk or CD and click the OK button.
italic text Italic text is used for the names of manuals and help topic titles, and to emphasize a word or phrase. For
example:
The InstaCal installation procedure is explained in the Quick Start Guide.
Never touch the exposed pins or circuit connections on the board.
Where to find more information
The following electronic documents provide helpful information relevant to the operation of the RedLab
1208FS.
The Quick Start Guide is available on our RedLab CD in the root directory.
The Guide to Signal Connections is available on our RedLab CD under „ICalUL\Documents“.
The Universal Library User's Guide is available on our RedLab CD under „ICalUL\Documents“.
The Universal Library Function Reference is available on our RedLab CD under „ICalUL\Documents“.
The Universal Library for LabVIEW™ User’s Guide is available on our RedLab CD under
„ICalUL\Documents“.
6
Chapter 1
Introducing the RedLab 1208FS
This user's guide contains all of the information you need to connect the RedLab 1208FS to your computer and
to the signals you want to measure.
The RedLab 1208FS is a USB 2.0 full-speed device supported under popular Microsoft
systems. It is designed for USB 1.1 ports, and was tested for full compatibility with both USB 1.1 and USB 2.0
ports.
The RedLab 1208FS features eight analog inputs, two 12-bit analog outputs, 16 digital I/O connections, and one
32-bit external event counter. The RedLab 1208FS is powered by the +5 volt USB supply from your computer.
No external power is required.
The analog inputs are software configurable for either eight 11-bit single-ended inputs, or four 12-bit
differential inputs. Sixteen digital I/O lines are independently selectable as input or output in two 8-bit ports.
A 32-bit counter can count TTL pulses. The counter increments when the TTL levels transition from low to
high (rising-edge).
A SYNC (synchronization) input / output line lets you pace the analog input acquisition of one USB module
from the clock output of another.
The RedLab 1208FS is shown in Figure 1. I/O connections are made to the screw terminals located along each
side of the RedLab 1208FS.
®
Windows® operating
Figure 1. RedLab 1208FS
7
RedLab 1208FS User's Guide Introducing the RedLab 1208FS
RedLab 1208FS block diagram
RedLab 1208FS functions are illustrated in the block diagram shown here.
USB
G= 1, 2, 4, 5, 8, 10, 16, 20
Full-speed
USB 2.0
Compliant
Interface
Screw terminal I/O connector
CAL
Port A
DIO
Port B
SYNC
TRIG_IN
CAL
Software features
Analog Input
8 single-ended
16
(11-bit) channels
or
SPI
8
4 differential
(12-bit) channels
Analog output
USB
Microcontroller
Figure 2. RedLab 1208FS functional block diagram
2 channels
(12-bit)
Event Counter
32-bit
1 channel
Screw terminal I/O connector
8
2
1
For information on the features of InstaCal and the other software included with your RedLab 1208FS, refer to
the Quick Start Guide that shipped with your device. The Quick Start Guide is also available in PDF on our
RedLab CD (root directory).
8
RedLab 1208FS User's Guide Introducing the RedLab 1208FS
Connecting a RedLab 1208FS to your computer is easy
Installing a data acquisition device has never been easier.
The RedLab 1208FS relies upon the Microsoft Human Interface Device (HID) class drivers. The HID class
drivers ship with every copy of Windows that is designed to work with USB ports. We use the Microsoft
HID because it is a standard, and its performance delivers full control and maximizes data transfer rates for
your RedLab 1208FS. No third-party device driver is required.
The RedLab 1208FS is plug-and-play. There are no jumpers to position, DIP switches to set, or interrupts
to configure.
You can connect the RedLab 1208FS before or after you install the software, and without powering down
your computer first. When you connect an HID to your system, your computer automatically detects it and
configures the necessary software. You can connect and power multiple HID peripherals to your system
using a USB hub.
You can connect your system to various devices using a standard four-wire cable. The USB connector
replaces the serial and parallel port connectors with one standardized plug and port combination.
You do not need a separate power supply module. The USB automatically delivers the electrical power
required by each peripheral connected to your system.
Data can flow two ways between a computer and peripheral over USB connections.
9
Installing the RedLab 1208FS
What comes with your RedLab 1208FS shipment?
As you unpack your RedLab 1208FS, verify that the following components are included.
Hardware
RedLab 1208FS (shown with cable)
Chapter 2
USB cable (2 meter length)
Additional documentation
In addition to this hardware user's guide, you should also receive the Quick Start Guide (available on our
RedLab CD (root directory)). This booklet supplies a brief description of the software you received with your
RedLab 1208FS and information regarding installation of that software. Please read this booklet completely
before installing any software or hardware.
10
RedLab 1208FS User's Guide Installing the RedLab 1208FS
Unpacking the RedLab 1208FS
As with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the RedLab 1208FS from its packaging, ground yourself using a wrist strap or by
simply touching the computer chassis or other grounded object to eliminate any stored static charge.
If your RedLab 1208FS is damaged, notify Meilhaus Electronic immediately by phone, fax, or e-mail. For
international customers, contact your local distributor where you purchased the RedLab 1208FS:
141/
Phone: +49 (0) 8
5271-188
Fax:
E-Mail: suppo
+49 (0) 8141/
5271-169
rt@meilhaus.com
Installing the software
Refer to the Quick Start Guide for instructions on installing the software Guide (available on our RedLab CD
(root directory)).
Installing the hardware
Be sure you are using the latest system software
Before you install your RedLab 1208FS, run Windows Update to update your operating system with the latest
HID and USB drivers.
To connect the RedLab 1208FS to your system, turn your computer on, and connect the USB cable to a USB
port on your computer or to an external USB hub that is connected to your computer. The USB cable provides
power and communication to the RedLab 1208FS.
When you connect the RedLab 1208FS for the first time, a series of
(Windows XP) or dialogs (other Windows versions) opens as the RedLab 1208FS is detected by your computer.
Found New Hardware popup balloons
It is normal for multiple dialogs to open when you connect the RedLab 1208FS for the first time. For additional
information, refer to the "Notes on installing and using the RedLab 1208FS" that was shipped with the RedLab
1208FS.
The last popup balloon or dialog states "Your new hardware is installed and ready to use," and the LED on the
RedLab 1208FS should flash and then remain lit. This indicates that communication is established between the
RedLab 1208FS and your computer.
11
RedLab 1208FS User's Guide Installing the RedLab 1208FS
You can install up to two RedLab 1208FS units on most computers. If you need to connect more than two
RedLab 1208FS units to your computer, contact Tech Support (Tel: +49-(0)8141/
(0)8141/
5271-169 or E-Mail: support@meilhaus.com).
5271-188, Fax: +49-
Caution! Do not disconnect any device from the USB bus while the computer is communicating with the
RedLab 1208FS, or you may lose data and/or your ability to communicate with the RedLab 1208FS.
If the LED turns off
If the LED is illuminated but then turns off, the computer has lost communication with the RedLab 1208FS. To
restore communication, disconnect the USB cable from the computer, and then reconnect it. This should restore
communication, and the LED should turn back on.
12
Chapter 3
Functional Details
Theory of operation - analog input acquisition modes
The RedLab 1208FS can acquire analog input data in two different modes – software paced and continuous
scan.
Software paced mode
In software paced mode, you can acquire one analog sample at a time. You initiate the A/D conversion by
calling a software command. The analog value is converted to digital and returned to the computer. You can
repeat this procedure until you have the total number of samples that you want from one channel.
The maximum throughput sample rate in software paced mode is system-dependent.
Continuous scan mode
In continuous scan mode, you can acquire data from up to eight channels. The analog data is continuously
acquired and converted to digital values until you stop the scan. Data is transferred in blocks of 31 samples from
the RedLab 1208FS to the memory buffer on your computer.
The maximum continuous scan rate of 50 kS/s is an aggregate rate. The total acquisition rate for all channels
cannot exceed 50 kS/s. You can acquire data from one channel at 50 kS/s, two channels at 25 kS/s, and four
channels at 12.5 kS/s. You can start a continuous scan with either a software command or with an external
hardware trigger event.
External components
The RedLab 1208FS has the following external components, as shown in Figure 3.
USB connector
LED
Screw terminal banks (2)
Srew terminal
Pins 21 to 40
LED
Srew terminal
Pins 1 to 20
USB
Figure 3. RedLab 1208FS external components
13
RedLab 1208FS User's Guide Functional Details
USB connector
The USB connector is on the right side of the RedLab 1208FS. This connector provides +5 V power and
communication. The voltage supplied through the USB connector is system-dependent, and may be less than
5 V. No external power supply is required.
LED
The LED on the front of the housing indicates the communication status of the RedLab 1208FS. It uses up to 5
mA of current and cannot be disabled. The table below defines the function of the RedLab 1208FS LED.
LED Illumination
LED Illumination Indication
Steady green The RedLab 1208FS is connected to a computer or external USB hub.
Blinks continuously Data is being transferred.
Screw terminal wiring
The RedLab 1208FS has two rows of screw terminals—one row on the top edge of the housing, and one row on
the bottom edge. Each row has 20 connections. Pin numbers are identified in Figure 4.
Pin 1 Pin 20
Pin 21 Pin 40
Figure 4. RedLab 1208FS Screw terminal pin numbers
Screw terminal – pins 1-20
The screw terminals on the top edge of the RedLab 1208FS (pins 1 to 20) provide the following connections:
Eight analog input connections (
Two analog output connections (
One external trigger source (
CH0 IN to CH7 IN)
D/A OUT 0 to D/A OUT 1)
TRIG_IN)
One SYNC terminal for external clocking and multi-unit synchronization (
One calibration terminal (
Five analog ground connections (
CAL)
AGND)
14
SYNC)
RedLab 1208FS User's Guide Functional Details
One ground connection (GND)
One external event counter connection (
CTR)
Screw terminal – pins 21-40
The screw terminals on the bottom edge of the (pins 21 to 40) provide the following connections:
16 digital I/O connections (
One power connection (
Three ground connections (
PortA0 to Port A7, and Port B0 to Port B7)
PC+5 V)
GND)
15
RedLab 1208FS User's Guide Functional Details
Main connector and pin out
Connector type Screw terminal
Wire gauge range 16 AWG to 30 AWG
AGND
AGND
CH7 IN
CH6 IN
AGND
CH5 IN
CH4 IN
AGND
CH3 IN
20 CTR
CH2 IN
19 SYNC
18 TRIG IN
17 GND
16 CAL1514 D/A OUT 1
13 D/A OUT 012111098765
4
3AGND
2CH1 IN
1CH0 IN
20 CTR
AGND
AGND
CH3 IN LO
CH3 IN HI
AGND
CH2 IN LO
19 SYNC
18 TRIG IN
17 GND
16 CAL1514 D/A OUT 1
13 D/A OUT 01211109
8
7CH2 IN HI
6AGND
5CH1 IN LO
4CH1 IN HI
3AGND
2CH0 IN LO
1CH0 IN HI
GND 40
Port B7 39
Port B6 38
Port B5 37
Port B4 36
GND 31
PC +5 V 30
GND 29
Port B3 35
Port B2 34
Port B1 33
Port A7 28
Port B0 32
8-channel single-ended mode pin out
GND 40
Port B7 39
Port B6 38
Port B5 37
Port A6 27
Port A5 26
Port A4 25
Port A3 24
Port A2 23
Port A1 22
Port A0 21
Port B4 36
GND 31
PC +5 V 30
GND 29
Port B3 35
Port B2 34
Port B1 33
Port A7 28
Port B0 32
Port A6 27
Port A5 26
Port A4 25
Port A3 24
Port A2 23
Port A1 22
Port A0 21
4-channel differential mode pin out
16
RedLab 1208FS User's Guide Functional Details
Analog input terminals (CH0 IN - CH7 IN)
You can connect up to eight analog input connections to the screw terminal containing pins 1 to 20 (CH0 IN
through
You can configure the analog input channels as eight single-ended channels or four differential channels. When
configured for differential mode, each analog input has 12-bit resolution. When configured for single-ended
mode, each analog input has 11-bit resolution, due to restrictions imposed by the A/D converter.
Single-ended configuration
When all of the analog input channels are configured for single-ended input mode, eight analog channels are
available. The input signal is referenced to signal ground (GND), and delivered through two wires:
The wire carrying the signal to be measured connects to CH# IN.
The second wire connects to AGND.
The input range for single-ended mode is ±10 V. No other ranges are supported in single-ended mode. Figure 5
illustrates a typical single-ended measurement connection.
CH7 IN.) Refer to the pinout diagrams on page 16 for the location of these pins.
Pin 1
CH0
Pin 3
GND
Figure 5. Single-ended measurement connection
Battery voltage should read as expected when the hardware is configured for single-ended mode.
Single-ended measurements using differential channels
To perform a single-ended measurement using differential channels, connect the signal to "CHn IN HI" input,
and ground the associated "CHn IN LO" input.
Differential configuration
When all of the analog input channels are configured for differential input mode, four analog channels are
available. In differential mode, the input signal is measured with respect to the low input.
The input signal is delivered through three wires:
The wire carrying the signal to be measured connects to CH0 IN HI, CH1 IN HI, CH2 IN HI, or
CH3 IN HI.
17
RedLab 1208FS User's Guide Functional Details
The wire carrying the reference signal connects to CH0 IN LO, CH1 IN LO, CH2 IN LO, or
CH3 IN LO.
The third wire connects to GND.
A low-noise precision programmable gain amplifier (PGA) is available on differential channels to provide gains
of up to 20 and a dynamic range of up to 12-bits. Differential mode input voltage ranges are ±20 V, ±10 V,
±5 V, ±4 V, ±2.5 V, ±2.0 V, ±1.25 V, and ±1.0 V.
In differential mode, the following two requirements must be met for linear operation:
Any analog input must remain in the −10V to +20V range with respect to ground at all times.
The maximum differential voltage on any given analog input pair must remain within the selected voltage
range.
The input [common-mode voltage + signal] of the differential channel must be in the −10 V to +20 V range in
order to yield a useful result. For example, you input a 4 V pp sine wave to CHHI, and apply the same sine
wave 180° out of phase to CHLO. The common mode voltage is 0 V. The differential input voltage swings from
4 V-(-4 V) = 8 V to -4 V-4 V = -8V. Both inputs satisfy the -10 V to +20 V input range requirement, and the
differential voltage is suited for the ±10 V input range (see Figure 6).
+4V
CHHI
0V
Measured Signal
-4V
8V Differential
+4V
CHLO
-4V
Figure 6. Differential voltage example: common mode voltage of 0 V
+/-8V
If you increase the common mode voltage to 11 V, the differential remains at ±8 V. Although the [commonmode voltage + signal] on each input now has a range of +7 V to +15 V, both inputs still satisfy the -10 V to
+20 V input requirement (see Figure 7).
+15V
Measured Signal
CHHI
CHLO
+11V
+11V
8V Differential
+/-8V
+7V
Figure 7. Differential voltage example: common mode voltage of 11 V
18
RedLab 1208FS User's Guide Functional Details
If you decrease the common-mode voltage to -7 V, the differential stays at ±8 V. However, the solution now
violates the input range condition of -10 V to +20 V. The voltage on each analog input now swings from -3 V to
-11 V. Voltages between -10 V and -3 V are resolved, but those below -10 V are clipped (see Figure 8).
CHHI
CHLO
-3V
-7V
-11V
-3V
-7V
-11V
3V
8V Differential
Figure 8. Differential voltage example: common mode voltage of -7 V
+/-7V
Measured Signal
Since the analog inputs are restricted to a −10 V to +20 V signal swing with respect to ground, all ranges except
±20V can realize a linear output for any differential signal with zero common mode voltage and full scale signal
inputs. The ±20 V range is the exception. You cannot put −20 V on CHHI and 0 V on CHLO since this violates
the input range criteria.
The table below shows some possible inputs and the expected results.
Sample inputs and differential results
CHHI CHLO Result
-20 V 0 V In Valid
-15 V +5 V In Valid
-10 V 0 V -10 V
-10 V +10 V -20 V
0 V +10 V -10 V
0 V +20 V -20 V
+10 V -10 V +20 V
+10 V 0 V +10 V
+15 V -5 V +20 V
+20 V 0 +20 V
For more information on analog signal connections
For more information on single-ended and differential inputs, refer to the Guide to Signal Connections (this
document is available on our RedLab CD (root directory))
19
RedLab 1208FS User's Guide Functional Details
Analog output terminals (D/A OUT 0 and D/A OUT 1)
You can connect up to two analog output connections to the screw terminal pins 13 and 14 (D/A OUT 0 and D/A
OUT 1). Refer to the pinout diagrams on page 16 for the location of these pins.
Each channel can be paced individually at rates up to 10,000 updates per second. Both channels can be paced
simultaneously using the same time base at 5000 updates per channel. The 0-4.096 V output range provides a
convenient 1 mV per LSB when setting the output voltage levels.
Digital I/O terminals (Port A0 to A7, and Port B0 to B7)
You can connect up to 16 digital I/O lines to the screw terminal containing pins 21 to 40 (Port A0 to Port A7,
Port B0 to Port B7.) Refer to the pinout diagrams on page 16 for the location of these pins. You can
and
configure each digital port for either input or output.
When you configure the digital bits for input, you can use the digital I/O terminals to detect the state of any
TTL level input. Refer to the switch shown in Figure 9 and the schematic shown in Figure 10. If the switch is
set to the +5 V input, Port A0 reads TRUE (1). If you move the switch to GND, Port A0 reads FALSE.
Pin 40
GND
Pin 30
PC +5 V
Pin 21
Port A0
Figure 9. Digital connection Port A0 detecting the state of a switch
Port A0
+5V+GND
Figure 10. Schematic showing switch detection by digital channel Port A0
For more information on digital signal connections
For more information on digital signal connections and digital I/O techniques, refer to the Guide to Signal
Connections (available on our RedLab CD (root directory)).
20
RedLab 1208FS User's Guide Functional Details
Power terminals
The PC +5V connection (pin 30) is on the bottom screw terminal of the RedLab 1208FS. Refer to the pinout
diagrams on page 16 for the location of this pin. This terminal draws power from the USB connector. The +5 V
screw terminal is a 5 volt output that is supplied by the host computer.
Caution! The +5 V terminal is an output. Do not connect to an external power supply or you may damage
the RedLab 1208FS and possibly the computer.
The maximum total output current that can be drawn from all RedLab 1208FS connections (power, analog and
digital outputs) is 420 mA. This maximum applies to most personal computers and self-powered USB hubs.
Bus-powered hubs and notebook computers may limit the maximum available output current to 100 mA.
Just connecting the RedLab 1208FS to your computer draws 80 mA of current from the USB +5 V supply.
Once you start running applications with the RedLab 1208FS, each DIO bit can draw up to 2.5 mA, and each
analog output can draw 15 mA. The maximum amount of +5 V current available for experimental use, over and
above that required by the RedLab 1208FS, is the difference between the total current requirement of the USB
(based on the application), and the allowed current draw of the PC platform (500 mA for desktop PCs and self-
powered hubs, or 100 mA for bus-powered hubs and notebook computers).
With all outputs at their maximum output current, you can calculate the total current requirement of the RedLab
1208FS USB +5 V as follows:
(RedLab 1208FS @ 80 mA) + (16 DIO @ 2.5 mA ea) + (2 AO @ 15 mA ea ) = 150 mA
For an application running on a PC or powered hub, the maximum available excess current is 500 mA−150 mA
= 350 mA. This number is the total maximum available current at the PC +5 V screw terminals. Measurement
Computing highly recommends that you figure in a safety factor of 20% below this maximum current loading
for your applications. A conservative, safe user maximum in this case would be in the 350-380 mA range.
Since laptop computers typically allow up to 100 mA, the RedLab 1208FS in a fully-loaded configuration may
be above that allowed by the computer. In this case, you must determine the per-pin loading in the application
to ensure that the maximum loading criteria is met. The per-pin loading is calculated by simply dividing the
+5 V by the load impedance of the pin in question.
Calibration terminal
The CAL connection (pin 16) is an output you should use only to calibrate the RedLab 1208FS. Refer to the
pinout diagrams
controlled via InstaCal.
on page 16 for the location of this pin. Calibration of the RedLab 1208FS is software-
Ground terminals
The four analog ground (AGND) connections provide a common ground for all RedLab 1208FS input channels.
Four ground (GND) connections provide a common ground for the
connections. Refer to the pinout diagrams
on page 16 for the location of the AGND and GND terminal pins.
DIO, TRIG_IN, CTR, SYNC and PC +5V
External trigger terminal
The TRIG_IN connection (pin 18) can be configured for either rising or falling edge. Refer to the pinout
diagrams on page 16 for the location of the TRIG_IN terminal pin.
SYNC terminal
The SYNC connection (pin 19) is a bidirectional I/O signal. You can use it for two purposes:
21
RedLab 1208FS User's Guide Functional Details
Configure as an external clock input to externally source the A/D conversions. The SYNC terminal
supports TTL-level input signals of up to 50 kHz.
Configure as an output to synchronize with a second USB unit and acquire data from 16 channels.
Refer to the pinout diagrams
on page 16 for the location of this pin. For more information on synchronizing
multiple units, refer to page 25.
Counter terminal
The CTR connection (pin 20) is input to the 32-bit external event. Refer to the pinout diagrams on page 16 for
the location of this pin. The internal counter increments when the TTL levels transition from low to high. The
counter can count frequencies of up to 1 MHz.
Accuracy
The overall accuracy of any instrument is limited by the error components within the system. Quite often,
resolution is incorrectly used to quantify the performance of a measurement product. While "12-bits" or "1 part
in 4096" does indicate what can be resolved, it provides little insight into the quality of an absolute
measurement. Accuracy specifications describe the actual results that can be realized with a measurement
device.
There are three types of errors which affect the accuracy of a measurement system:
offset
gain
nonlinearity.
The primary error sources in the RedLab 1208FS are offset and gain. Nonlinearity is small in the RedLab
1208FS, and is not significant as an error source with respect to offset and gain.
Figure 11 shows an ideal, error-free, RedLab 1208FS transfer function. The typical calibrated accuracy of the
RedLab 1208FS is range-dependent, as explained in the "Specifications
" chapter on page 27. We use a ±10 V
range here as an example of what you can expect when performing a measurement in this range.
Input Vo lta g e
+FS
Output Code
0
Figure 11. Ideal ADC transfer function
2048
-FS
4095
22
RedLab 1208FS User's Guide Functional Details
V
The RedLab 1208FS offset error is measured at mid-scale. Ideally, a zero volt input should produce an output
code of 2048. Any deviation from this is an offset error. Figure 12 shows the RedLab 1208FS transfer function
with an offset error. The typical offset error specification on the ±10 V range is ±9.77 mV. Offset error affects
all codes equally by shifting the entire transfer function up or down along the input voltage axis.
The accuracy plots in
Figure 12 are drawn for clarity and are not drawn to scale.
Input Vo lta g e
+FS
Idea l
2
2048
9.77mV
Output Co de
4095
0
Ac t ua l
Offset= 9.77mV
-FS
Figure 12. ADC transfer function with offset error
Gain error is a change in the slope of the transfer function from the ideal, and is typically expressed as a
percentage of full-scale. Figure 13 shows the RedLab 1208FS transfer function with gain error. Gain error is
easily converted to voltage by multiplying the full-scale (
FS) input by the error.
The accuracy plots in
Figure 13 are drawn for clarity and are not drawn to scale.
Input Vo lta g e
+FS
Id ea l
Gain e rror= + 0.2%, or + 20 m
Gain error= -0.2%, or -20 m V
Ac t ua l
Output Code
0
2048
4095
-FS
Figure 13. ADC Transfer function with gain error
For example, the RedLab 1208FS exhibits a typical calibrated gain error of ±0.2% on all ranges. For the ±10 V
range, this would yield 10 V × ±0.002 = ±20 mV. This means that at full scale, neglecting the effect of offset for
23
RedLab 1208FS User's Guide Functional Details
V
V
the moment, the measurement would be within 20 mV of the actual value. Note that gain error is expressed as a
ratio. Values near ±FS are more affected from an absolute voltage standpoint than are values near mid-scale,
which see little or no voltage error.
Combining these two error sources in Figure 14, we have a plot of the error band of the RedLab 1208FS for the
±10 V range. This is a graphical version of the typical accuracy specification of the product.
The accuracy plots in
Ideal + 9.77mV + 20 mV
Id ea l -(9.77 m V + 20 m V)
Figure 14 are drawn for clarity and are not drawn to scale
Idea l
Input Volta g e
+FS
9.77mV
0
2048
-FS
Figure 14. Error band plot
Idea l + 9.7 7m V + 20 m
Idea l + 9.7 7m V + 20 m
Idea l
Ideal -(9.77mV + 20 mV)
Output Code
4095
24
RedLab 1208FS User's Guide Functional Details
RedLab 1208FS channel gain queue feature
The RedLab 1208FS's channel gain queue feature allows you to set up a scan sequence with a unique perchannel gain setting and channel sequence.
The channel gain queue feature removes the restriction of using an ascending channel sequence at a fixed gain.
This feature creates a channel list which is written to local memory on the RedLab 1208FS. The channel list is
made up of a channel number and range setting. An example of a four-element list is shown in the table below.
Sample channel gain queue list
Element Channel Range
0 CH0 BIP10V
1 CH0 BIP5V
2 CH7 BIP10V
3 CH2 BIP1V
When a scan begins with the gain queue enabled, the RedLab 1208FS reads the first element, sets the
appropriate channel number and range, and then acquires a sample. The properties of the next element are then
retrieved, and another sample is acquired. This sequence continues until all elements in the gain queue have
been selected. When the end of the channel list is detected, the sequence returns to the first element in the list.
This sequence repeats until the specified number of samples is gathered. You must carefully match the gain to
the expected voltage range on the associated channel — otherwise, an over range condition can occur. Although
this condition does not damage the RedLab 1208FS, it does produce a useless full-scale reading. It can also
introduce a long recovery time from saturation, which can affect the next measurement in the queue.
Synchronizing multiple units
You can connect the SYNC pin of two RedLab 1208FS units together in a master/slave configuration and
acquire data from the analog inputs of both devices using one clock. When the SYNC pin is configured as an
output, the internal A/D pacer clock is sent to the screw terminal. You can use this signal as a clock input to a
second USB by connecting it to the SYNC pin of the second USB.
When used as a clock input, the SYNC pin operates in one of two modes – Continuous or Gated.
In the default Continuous mode, a RedLab 1208FS ignores the first clock pulse in order to ensure adequate
setup time. Use this mode if the unit is being paced from a continuous clock source, such as a generator.
In the Gated mode, it is assumed that the clock signal will be held off for an adequate amount of time for setup
to occur. No clock pulses are ignored. Use this mode if the RedLab 1208FS is set up as a slave and the source of
the external clock is another USB.
The SYNC pin (pin 19) is set for pacer output by default. To synchronize a master RedLab 1208FS with a slave
RedLab 1208FS and acquire data, follow the steps below.
Article I. Connect the SYNC pin of the master RedLab 1208FS to the SYNC pin of the slave RedLab
1208FS.
Article II. Run InstaCal.
Article III. From the
want to use as a slave. The
Article IV. Select Gated from the
PC Board List on the InstaCal main form, double-click on the RedLab 1208FS you
Board Configuration dialog opens.
Ext. Clock Type drop-down list.
25
RedLab 1208FS User's Guide Functional Details
Article V. Set the Universal Library EXTCLOCK option with cbAInScan()/AInScan for the slave RedLab
1208FS to enable pacing from the master USB device.
This InstaCal option does not affect internally paced acquisition. It only affects scans that use the
option.
EXTCLOCK
An example of a master/slave configuration is shown below.
Master
RedLab 1208FS
Configure the SYNC pin
for output
SYNC pin
pin 19
Figure 15. Configuring for synchronous data acquisition
Configure the SYNC pin
for input
Slave
RedLab 1208FS
Set he Universal Libary EXTCLOCK
option with cbAInScan() / AInScan() for
the slave RedLab 1208FS
When you are operating one RedLab 1208FS, do not set the EXTCLOCK option unless you are using an external
clock for A/D pacing.
26
Chapter 4
Specifications
Typical for 25°C unless otherwise specified.
Specifications in italic text are guaranteed by design.
Analog input
Table 1. Analog input specifications
Parameter Conditions Specification
A/D converter type
Input voltage range for linear operation,
single-ended mode
Input common-mode voltage range for linear
operation, differential mode
Absolute maximum input voltage CHx to GND ±28 V max
Input impedance 122KOhm
Input current (Note 1)
Number of channels
Input ranges, single-ended mode
Input ranges, differential mode
Throughput (Note 2)
Channel gain queue Up to 16 elements
CAL accuracy CAL = 2.5 V ±36.25 mV max
Integral linearity error
Differential linearity error
Repeatability
Trigger source Software selectable External digital: TRIG_IN
Note 1: Input current is a function of applied voltage on the analog input channels. For a given input
voltage, V
, the input leakage is approximately equal to (8.181*Vin-12) µA.
in
CHx to GND ±10 volts (V) max
CHx to GND -10 V min, +20 V max
Vin = +10 V 70 microamperes (µA) typ
Vin = 0 V -12 µA typ
Vin = -10 V -94 µA typ
Software paced
Continuous scan 50 kilosamples per second (kS/s)
Differential 12 bits, no missing codes Resolution (Note 3)
Single-ended 11 bits
Source 5 milliamperes (mA) max CAL current
Sink 20 µA min, 100 µA typ
Successive approximation type
8 single-ended / 4 differential, software
selectable
±10 V, G=2
±20 V, G=1
±10 V, G=2
±5 V, G=4
±4 V, G=5
±2.5 V, G=8
±2.0 V, G=10
±1.25 V, G=16
±1.0 V, G=20
Software selectable
250 samples per second (S/s) typ,
PC-dependent
Software configurable channel, range, and
gain.
±1 least significant bit (LSB) typ
±0.5 LSB typ
±1 LSB typ
27
RedLab 1208FS User's Guide Specifications
Note 2: Maximum throughput scanning to PC memory is machine dependent. The rates specified are for
Windows XP only. Maximum rates on operating systems that predate XP may be less and must be
determined through testing on your machine
Note 3: The AD7870 converter only returns 11-bits (0-2047 codes) in single-ended mode.
Table 2. Accuracy, differential mode
Range Accuracy (LSB)
±20 V 5.1
±10 V 6.1
±5 V 8.1
±4 V 9.1
±2.5 V 12.1
±2 V 14.1
±1.25 V 20.1
±1 V 24.1
Table 3. Accuracy, single-ended mode
Range Accuracy (LSB)
±10 V 4.0
Table 4. Accuracy components, differential mode - All values are (±)
Range % of Reading Gain Error at full scale (FS)
Offset (mV) Accuracy at FS (mV)
(millivolts (mV))
±20 V 0.2 40 9.766 49.766
±10 V 0.2 20 9.766 29.766
±5 V 0.2 10 9.766 19.766
±4 V 0.2 8 9.766 17.766
±2.5 V 0.2 5 9.766 14.766
±2 V 0.2 4 9.766 13.766
±1.25 V 0.2 2.5 9.766 12.266
±1 V 0.2 2 9.766 11.766
Table 5. Accuracy components, single-ended mode - All values are (±)
Range % of Reading Gain Error at FS (mV) Offset (mV) Accuracy at FS (mV)
±10 V 0.2 20 19.531 39.531
Table 6. Noise performance, differential mode
Range Typical counts Least significant bit
root mean square
(LSB
rms)
±20 V 2 0.30
±10 V 2 0.30
±5 V 3 0.45
±4 V 3 0.45
±2.5 V 4 0.61
±2 V 5 0.76
±1.25 V 7 1.06
±1 V 8 1.21
28
RedLab 1208FS User's Guide Specifications
Table 7. Noise performance, single-ended mode
Range Typical Counts LSB
±10 V 2 0.30
rms
Analog output
Table 8. Analog output specifications
Parameter Conditions Specification
Resolution
Output range
Number of channels
Throughput (Note 4)
Power on and reset voltage
Output drive Each D/A OUT 15 mA
Slew rate
Note 4: Maximum throughput scanning to PC memory is machine dependent. The rates specified are for
Windows XP only. Maximum rates on operating systems that predate XP may be less and must be
determined through testing on your machine.
Software paced 250 S/s single channel typical, PC dependent
Single channel, continuous scan 10 kS/s
Dual channel, continuous scan,
simultaneous update
Table 9. Analog output accuracy, all values are (±)
12-bits, 1 in 4096
0 – 4.096 V, 1 mV per LSB.
2
5 kS/s
Initializes to 000h code
0.8V/microsecond (µs) typ
Range Accuracy (LSB)
0-4.096 V 4.0 typ, 45.0 max
Table 10. Analog output accuracy components, all values are (±)
Range % of FSR Gain Error at FS (mV) Offset (mV)
(Note 5)
0-4.096 V 0.1 typ, 0.9 max 4.0 typ, 36.0 max 1.0 typ, 9.0 max 4.0 typ, 45.0 max
Note 5: Negative offsets will result in a fixed zero-scale error or “dead band.” At the maximum offset of -
Accuracy at FS
(mV)
9 mV, any input code of less than 0x009 will not produce a response in the output.
Digital input/output
Table 11. Digital I/O specifications
Digital type CMOS
Number of I/O 16 (Port A0 through A7, Port B0 through B7)
Configuration 2 banks of 8
Pull up/pull-down configuration
Input high voltage 2.0 V min, 5.5 V absolute max
Input low voltage 0.8 V max, –0.5 V absolute min
Output high voltage (IOH =
-2.5 mA)
Output low voltage (IOL =
2.5 mA)
Power on and reset state Input
All pins pulled up to Vs via 47K resistors (default). Positions available for pull down
to ground. Hardware selectable via zero ohm (Ω) resistors as a factory option.
3.8 V min
0.7 V max
29
RedLab 1208FS User's Guide Specifications
External trigger
Table 12. Digital trigger specifications
Parameter Conditions Specification
Trigger source (Note 6) External Digital TRIG_IN
Trigger mode Software selectable
Trigger latency
Trigger pulse width
Input high voltage
Input low voltage
Input leakage current
Note 6: TRIG_IN is a Schmitt trigger input protected with a 1.5 kilohm (kΩ) series resistor.
Edge sensitive: user configurable for CMOS compatible
rising or falling edge.
10 µs max
1 µs min
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
±1.0 µA
External clock input/output
Table 13. External clock I/O specifications
Parameter Conditions Specification
Pin name
Pin type
Input clock rate
Input leakage current Input mode ±1.0 µA
Input high voltage
Input low voltage
Note 7: SYNC is a Schmitt trigger input and is over-current protected with a 200 Ω series resistor.
Output (default) Outputs internal A/D pacer clock. Software selectable direction
Input Receives A/D pacer clock from external source.
Input mode 1 µs min Clock pulse width
Output mode 5 µs min
IOH = -2.5 mA 3.3 V min Output high voltage (Note 7)
No load 3.8 V min
IOL = 2.5 mA 1.1 V max Output low voltage (Note 7)
No load 0.6 V max
SYNC
Bidirectional
50 KHz, maximum
4.0 V min, 5.5 V absolute max
1.0 V max, –0.5 V absolute min
30
RedLab 1208FS User's Guide Specifications
Counter
Table 14. Counter specifications
Pin name (Note 8) CTR
Counter type Event counter
Number of channels 1
Input type TTL, rising edge triggered
Input source CTR screw terminal
Resolution 32 bits
Schmitt trigger hysteresis 20 mV to 100 mV
Input leakage current ±1 µA
Maximum input frequency 1 MHz
High pulse width 500 ns min
Low pulse width 500 ns min
Input high voltage 4.0 V min, 5.5 V absolute max
Input low voltage 1.0 V max, –0.5 V absolute min
Note 8: CTR is a Schmitt trigger input protected with a 1.5K Ω series resistor.
Non-volatile memory
Table 15. Non-volatile memory specifications
EEPROM 1,024 bytes
EEPROM Configuration
Address Range Access Description
0x000-0x07F Reserved 128 bytes system data
0x080-0x1FF Read/write 384 bytes cal data
0x200-0x3FF Read/write 512 bytes user area
Microcontroller
Table 16. Microcontroller specifications
Type High performance 8-bit RISC microcontroller
Program Memory 16,384 words
Data Memory 2,048 bytes
Power
Table 17. Power specifications
Parameter Conditions Specification
Supply current (Note 9)
Note 9: This is the total current requirement for the RedLab 1208FS which includes up to 10 mA for the status
LED.
Connected to self-powered hub
Connected to externally-powered root port hub
Connected to bus-powered hub 4.1 V min, 5.25 V max
Connected to self-powered hub
Connected to externally-powered root port hub
Connected to bus-powered hub 20 mA max
80 mA
4.5 V min, 5.25 V max +5V USB power available (Note 10)
420 mA max Output current (Note 11)
31
RedLab 1208FS User's Guide Specifications
Note 10: Self-powered hub refers to a USB hub with an external power supply. Self-powered hubs allow a
connected USB device to draw up to 500 mA.
Root port hubs reside in the PC’s USB host controller. The USB port(s) on your PC are root port hubs.
All externally powered root port hubs (desktop PCs) provide up to 500 mA of current for a USB
device. Battery-powered root port hubs provide 100 mA or 500 mA, depending upon the manufacturer.
A laptop PC that is not connected to an external power adapter is an example of a battery-powered root
port hub.
Bus powered hubs receive power from a self-powered or root port hub. In this case the maximum
current available from the USB +5 V is 100 mA. The minimum USB +5 V voltage level can be as low
as 4.1 V.
Note 11: This refers to the total amount of current that can be sourced from the USB +5 V, analog outputs
and digital outputs.
General
Table 18. General specifications
Parameter Conditions Specification
Device type
Device compatibility
USB 2.0 full speed
USB 1.1, USB 2.0
Environmental
Table 19. Environmental specifications
Operating temperature range 0 to 70 °C
Storage temperature range -40 to 70 °C
Humidity 0 to 90% non-condensing
Mechanical
Table 20. Mechanical specifications
Dimensions 79 millimeters (mm) long x 82 mm wide x 25 mm high
USB cable length 3 meters max
User connection length 3 meters max
Main connector and pin out
Table 21. Main connector specifications
Connector type Screw terminal
Wire gauge range 16 AWG to 30 AWG
32
RedLab 1208FS User's Guide Specifications
4-channel differential mode
Pin Signal Name Pin Signal Name
8-channel single-ended mode
Pin Signal Name Pin Signal Name
+
33
Meilhaus Electronic GmbH
Am Sonnenlicht 2
D-82239 Alling, Germany
Phone: +49 (0)8141 - 5271-0
Fax: +49 (0)8141 - 5271-129
E-Mail: sales@meilhaus.com
http://www.meilhaus.com
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