Acumen Barcode Reader SDR2 USB User Manual

ACUMEN INSTRUMENTS CORPORATION  
DataBridge™ SDR2-USB  
Configuration Guide  
revision 1.0 • 04/2009  
 
Copyright  
This document is copyrighted by Acumen Instruments Corporation with all rights reserved.  
No part of this document may be reproduced in any form without prior written consent of  
Acumen Instruments Corporation.  
Copyright © 2009 by Acumen Instruments Corporation. All rights reserved.  
Disclaimer  
This manual has been thoroughly reviewed for accuracy, and every effort has been made to  
ensure that the information is accurate and complete. However, different versions of this  
product have different features and capabilities, and this manual only reflects one of those  
versions. Therefore, Acumen Instruments Corporation assumes no responsibility for errors,  
omissions or defects in this material, and shall not be liable for any damages resulting from  
their use.  
The information in this document is subject to change without notice.  
ACUMEN INSTRUMENTS CORPORATION MAKES NO WARRANTY OF ANY KIND WITH RESPECT TO  
THIS DOCUMENT, EITHER EXPRESSED OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY  
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 
 
SDR2-USB Configuration Guide rev 1.0  
Getting Started  
Table of Contents  
1. Getting Started ..................................................................... 5  
1.1  
1.2  
1.3  
1.4  
Overview.................................................................................................5  
Before you start ......................................................................................6  
A quick guide to the DataBridge SDR2-USB ..........................................6  
Deploying the DataBridge SDR2-USB....................................................7  
1.4.1 Connecting power to your SDR2-USB....................................................7  
1.4.2 Configuring your SDR2-USB via the setup file........................................7  
1.4.3 Congratulations!......................................................................................8  
2. Configuring the DataBridge SDR2-USB ............................... 9  
2.1  
2.2  
Comments ............................................................................................10  
Setting date and time............................................................................10  
Step 1: Edit setup.txt..........................................................................10  
Step 2: Insert USB storage device and apply power..........................11  
Step 3: Synchronize the SDR2-USB clock.........................................11  
Step 4: Re-edit setup.txt ....................................................................11  
Configuring the data port ......................................................................11  
Specifying a filename and folder...........................................................12  
Notes about filenames.......................................................................12  
Configuring file creation behavior .........................................................13  
Adding time stamps to recorded files....................................................13  
Testing your configuration ....................................................................14  
2.3  
2.4  
2.5  
2.6  
2.7  
3. Operations.......................................................................... 15  
3.1  
3.2  
Setup file reading..................................................................................15  
Record mode operation ........................................................................15  
3.2.1 Receiving data......................................................................................15  
3.2.2 Stopping recording ...............................................................................16  
3.2.3 Power failure and improper shutdowns.................................................16  
3.2.4 Full storage media................................................................................16  
3.2.5 Formatting the storage media...............................................................17  
3.2.6 Partitions...............................................................................................17  
3.3  
3.4  
Resetting to factory defaults .................................................................18  
Lithium battery maintenance.................................................................18  
4. Setup File Reference.......................................................... 19  
4.1.1 Initial Setup Commands........................................................................19  
4.1.2 Data Port Setup Commands.................................................................20  
4.1.3 Recording Behavior Commands...........................................................20  
4.1.4 Scheduled File Closing Commands......................................................21  
4.1.5 Time Stamping Commands ..................................................................21  
4.1.6 Other Commands .................................................................................22  
5. J4 Remote Control Port...................................................... 23  
5.1  
5.2  
5.3  
5.4  
5.5  
Overview...............................................................................................23  
Location................................................................................................23  
Functions..............................................................................................24  
Pinout and Mating Cable ......................................................................24  
Force-Record Shunt Installation ...........................................................25  
 
Getting Started  
SDR2-USB Configuration Guide rev 1.0  
6. Service and Support ........................................................... 27  
6.1  
Exception Codes .................................................................................. 27  
Exception 2: Root Directory Full ........................................................ 27  
Exception 3: Disk Full........................................................................ 27  
Exception 4: Bad Boot Record .......................................................... 28  
Exception 5: Hardware Error ............................................................. 28  
Exception 6: EEPROM Error ............................................................. 28  
Exception 7: Cache Error .................................................................. 28  
Exception 8: Buffer Error (firmware error).......................................... 28  
Exception 9: Tasking Error (firmware error)....................................... 28  
Exception 10: USB Error ................................................................... 28  
Exception 11: Directory Creation Error.............................................. 28  
Exception 12: FAT12 File System Detected...................................... 28  
Contacting Acumen Instruments Corporation....................................... 29  
6.2  
6.2.1 Technical support................................................................................. 29  
6.2.2 U.S. Mail............................................................................................... 29  
6.2.3 E-mail................................................................................................... 29  
6.2.4 World Wide Web .................................................................................. 29  
6.3  
6.4  
Returning Equipment............................................................................ 29  
Warranty............................................................................................... 30  
6.4.1 One year warranty................................................................................ 30  
6.4.2 Exclusions............................................................................................ 30  
6.4.3 Limitations............................................................................................ 30  
A. Serial Port Basics ............................................................... 31  
A.1  
A.2  
Serial specifications.............................................................................. 31  
Data rates............................................................................................. 31  
A.2.1 Data rates and the UART..................................................................... 32  
A.3 More asynchronous serial parameters ................................................. 32  
A.3.2 DTE and DCE ...................................................................................... 33  
A.3.3 Handshaking ........................................................................................ 34  
A.3.4 Voltage levels....................................................................................... 34  
B. Specifications ..................................................................... 37  
B.1  
Electrical specifications ........................................................................ 37  
B.1.5 J7 rear power receptacle pin configuration........................................... 37  
B.1.6 J1 power receptacle pin configuration .................................................. 38  
B.2  
B.3  
B.4  
Serial communications ......................................................................... 38  
USB socket .......................................................................................... 38  
Mechanical Specifications .................................................................... 38  
 
SDR2-USB Configuration Guide rev 1.0  
Getting Started  
1
1. Getting Started  
1.1 Overview  
DataBridge SDR2-USB serial data recorders record RS-232 serial data to  
industry-standard mass storage using an Microsoft Windows™-compatible  
FAT file format. The SDR2-USB is equipped with a USB 2.0 socket and is  
designed for use with USB storage media such as USB flash memory keys.  
During Record mode, the SDR2-USB’s data port accepts RS-232 serial data  
from your data source. The SDR2-USB data port supports baud rates up to  
921600 bps and RTS/CTS hardware handshaking for reliable high-speed  
communication. Your SDR2-USB is also equipped with a real-time clock,  
power-saving features, non-volatile memory, and a resume-on-power failure  
feature. The SDR2-USB features a one-button front panel user interface  
that starts and stops recording.  
NOTE: The data  
source is a device that  
transmits serial data  
for use by a computer,  
printer, or data logger.  
SDR2-USB configuration is performed by editing a setup file on the USB  
storage device.  
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Getting Started  
SDR2-USB Configuration Guide rev 1.0  
1.2 Before you start  
Before you start, be sure you have the following items available:  
DataBridge SDR2-USB  
A 5-30VDC power supply  
RS-232 DB9 serial cable  
The device you wish to record from (serial data source)  
1.3 A quick guide to the DataBridge  
SDR2-USB  
On the front of the SDR2-USB are the USB "A" socket, record button, and  
LED indicators. The SDR2-USB can be toggled in and out of record mode  
using the record button located on the front panel. The LED indicators  
show the SDR2-USB’s current recording status. The data indicator flashes  
when data is received and is used to verify data reception from your data  
source.  
Record Button  
Power Indicator  
Record Indicator  
Fault Indicator  
Data Indicator  
Figure 1.1. SDR2-USB Front Panel Controls.  
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SDR2-USB Configuration Guide rev 1.0  
Getting Started  
On the rear is the male nine-pin D-subminiature connector (DB9M) for the  
data port. The 5 to 30 VDC power input is also located on the rear panel.  
From serial data source  
5 to 30 VDC Power  
Figure 1.2. SDR2-USB Rear Panel.  
1.4 Deploying the DataBridge SDR2-USB  
1.4.1 Connecting power to your SDR2-USB  
The SDR2-USB starter kit includes a 120VAC power supply that connects  
via the rear panel. If you use an alternate power source, it should be capable  
of sourcing at least 1W power. When you apply power the power indicator  
should light and the other indicators should flash in sequence.  
1.4.2 Configuring your SDR2-USB via the setup file  
To successfully receive data from your data source, the SDR2-USB must  
know at which baud rate the data source is transmitting. Configure the  
recorder for this baud rate using the setup file.  
NOTE: Your  
computer’s Windows  
installation may  
display different drive  
letters, file types, etc.  
due to differences in  
Windows versions,  
configurations, and  
software installations.  
Insert the USB device you intend to use for recording into your PC’s USB  
socket. Usually, Windows will respond by displaying the contents of the  
device. If this doesn’t occur, navigate to the device’s drive letter (e.g. J:).  
Right-click within your drive’s contents in Windows Explorer, then select  
“New” and “Text Document.” When prompted, name the file setup.txt  
(See Figure 1.3).  
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Getting Started  
SDR2-USB Configuration Guide rev 1.0  
Figure 1.3. Creating setup.txt.  
Once the file is created, double-click it to open the file in Windows Notepad  
and enter “DataPortBaud=9600” as shown in Figure 1.4. This tells the  
SDR2-USB to communicate with your data source at 9600 baud. The baud  
rate for your serial data source may differ from 9600 bps.  
Figure 1.4. Editing a simple setup.txt file.  
Close Windows Notepad, then right-click the USB device’s drive letter and  
click “Eject” to safely remove the device from your system.  
Insert the USB device into the SDR2-USB, connect your serial data source  
to the DB9M connector, and connect power. The SDR2-USB will display a  
left-to-right-to-left flashing sequence. If your data source is outputting data,  
the front panel “data” indicator will flash as data arrives.  
1.4.3 Congratulations!  
You’ve set up the SDR2-USB to communicate with your device!  
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SDR2-USB Configuration Guide rev 1.0  
Configuring the DataBridge SDR2-USB  
2
2. Configuring the  
DataBridge  
SDR2-USB  
Now that you’ve successfully edited the SDR2-USB’s setup.txt file, you are  
ready to configure it for use with your serial data source. Using the setup  
file, you can:  
Set the date and time.  
Configure handshaking and data word format for your device.  
Specify a directory to record files to.  
Specify a filename for recording.  
Select how and when data is written to files.  
Add time stamps to recorded files.  
Before you begin, be sure you have the documentation available for the  
device you’ll connect to your SDR2-USB. If possible, be sure you can  
communicate with the data source using the supplied software and/or your  
communications software. An intimate knowledge of your data source's  
communications standards will make connecting it to the SDR2-USB  
simple.  
Note: all SDR2-USB settings are persistent. Changes made via the  
setup file will be retained by the recorder after power is removed and  
until they are reversed in the setup file or the recorder is restored to  
factory defaults (see Section 3.4).  
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Configuring the DataBridge SDR2-USB  
SDR2-USB Configuration Guide rev 1.0  
2.1 Comments  
Within the setup.txt file, it is useful to record comments documenting the  
settings chosen and why some configuration choices were made. Comments  
are also useful for temporarily disabling setting(s) for the purposes of testing  
multiple settings.  
Figure 2.1. Use of comments to switch between GPS  
receivers.  
To create a comment line in the setup file, place to forward slashes (“//”) at  
the beginning of a line. The SDR2-USB will completely ignore any line that  
begins with //. To disable a particular line temporarily, insert // at the  
beginning of the line.  
2.2 Setting date and time  
The SDR2-USB features a real-time clock that reports a file’s last modified  
date and time. The real-time clock accurate and battery-backed, so setting  
the date and time is seldom necessary.  
Unlike DataBridge SDR products equipped with a configuration port,  
setting the SDR2-USB’s date and time is a four-step process.  
Step 1: Edit setup.txt  
Add CurrentDate=and CurrentTime=lines to the setup file (see  
Figure 2.2) with a time value 1-2 minutes ahead of the current time. The  
year field must be specified using 4 digits, while all other fields must be  
specified using 2 digits. Date is specified in YYYY/MM/DD format, and  
time is entered using 24-hour format. Take note of this time for use in  
step 3.  
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SDR2-USB Configuration Guide rev 1.0  
Configuring the DataBridge SDR2-USB  
Figure 2.2. Setting date and time.  
Step 2: Insert USB storage device and apply power  
Eject the USB storage device and remove it from the computer. Insert the  
USB device into the SDR2-USB, and connect power. The SDR2-USB will  
display its usual flashing pattern, then read the setup file and turn on all 4  
front-panel LED indicators. If precise setting is desired, monitor a  
stopwatch or computer clock.  
Step 3: Synchronize the SDR2-USB clock  
When the stopwatch or computer clock reaches the time specified in step 1,  
press the record button on the front panel. The SDR2-USB will the operate  
normally.  
Step 4: Re-edit setup.txt  
Remove the USB storage device from the SDR2-USB and edit the setup file  
using Windows Notepad on the PC. Disable the CurrentDate= and  
CurrentTime= lines by inserting //characters before them. These lines can  
also be deleted if date/time setting will not be performed again.  
2.3 Configuring the data port  
Before the SDR2-USB and your data source can communicate, they must  
interact at the same data rate and using the same data format.  
The SDR2-USB's data port is, by default, configured to communicate at  
115200 bps.  
NOTE: By default,  
the SDR2-USB uses a  
serial data format of  
eight data bits, no  
parity, and one stop bit  
(8N1). Most serial  
devices use this  
If your data source can communicate at 115200 bps (also referred to as  
115200 baud), it may be easiest to configure it for 115200 bps. For devices  
with a fixed data rate, you will need to set the SDR2-USB's data port baud  
rate to match your data source. You may also wish to choose a higher data  
rate and hardware handshaking if your data source sends a high volume of  
data.  
format.  
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Configuring the DataBridge SDR2-USB  
SDR2-USB Configuration Guide rev 1.0  
Hardware handshaking prevents a data source from sending data when the  
SDR2-USB is not ready to receive it – the SDR2-USB can “shut off” the  
transmitting data source if, for example, the USB storage media is slow or  
not present.  
Be sure that your serial data source and the SDR2-USB use the same  
handshaking settings. If your data source monitors the handshaking signals  
but the SDR2-USB doesn't send the appropriate signal, the software may  
never transmit data.  
To change the baud rate for the data port, add the line DataPortBaud= to  
the setup file as in Figure 1.4. Common baud rates are 300, 1200, 2400,  
4800, 9600, 19200, 38400, 57600, 115200, 230400 bps, although the  
SDR2-USB can handle “nonstandard” baud rates as well.  
To enable hardware handshaking, include the line DataPortHandshake= in  
in the file, with a value of 1 for enabled or 0 for disabled.  
Finally, while 8N1 communication is used by the vast majority of data  
sources, some devices communicate using nonstandard data word formats  
such as 7E1. To specify this, add the line DataPortWordFormat= to the  
setup file, with a value of 8N1, 7E1, etc.  
2.4 Specifying a filename and folder  
By default, the SDR2-USB records data to a file called SDR-0000.DAT  
located in the DATAsubfolder in the storage device's root directory. You can  
keep this filename or specify a new filename that reflects the data it contains.  
For example, you may wish to use PRESSURE.TXTfor pressure data or a  
name like TEMP1109.TXTfor temperature data from November 2009.  
Likewise, your choice of folder names may reflect something about the data  
it contains.  
Notes about filenames  
When you specify a filename, it must conform to the FAT 8+3 filename  
format. This means that files contain up to 8 characters, a period ("dot"), and  
up to three more characters. For example, BRIDGE.DAT, ABCDEFGH.123,  
and 1are all valid filenames, while DATA.FILE, and JOHNSMITH.TXTare  
not. The SDR2-USB ignores characters you type that are not allowed in  
FAT16 filenames, such as: \/*|[]. Specifying illegal characters can  
sometimes result in unpredictable filenames.  
To specify the name of the file the SDR2-USB will use for recording data,  
include the line Filename= in your setup file and specify a folder and  
filename after the equals sign. For example, to record to a folder named  
“GPSDATA” and use a filename of “GPS-0000.TXT”, include the line  
Filename=GPSDATA\GPS-0000.TXT (see Figure 2.3).  
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Configuring the DataBridge SDR2-USB  
Figure 2.3. Specifying filename and folder for recording.  
2.5 Configuring file creation behavior  
Be default, the SDR2-USB creates a new file in the recording folder every  
time recording is initiated, generating a new, unique filename based on the  
previous filename. To instruct the SDR2-USB to always append data to the  
existing file when recording starts, add the line Append=1 to the setup file.  
The SDR2-USB can also be configured to periodically restart recording  
based on file size, a period of time in seconds, or at specific times of day.  
Use the line Fileclose= to enable this periodic scheduled file closing, and  
FileCloseBytes=, FileCloseSeconds=, or StartTime= and StopTime= to  
enable one of these modes (see section 4.1.4 for more details).  
Finally, the SDR2-USB can be configured to overwrite the oldest file found  
in the recording directory if necessary. When this mode is enabled, the  
SDR2-USB will delete the oldest file on the disk whenever recording starts  
and the storage media has less than 1 megabyte of free disk space.  
Use this option with scheduled file closing to configure the SDR2-USB as a  
circular buffer that contains only the most recently received data. To enable  
overwrite-oldest mode, include the line OverWriteOldest=1 in the setup  
file.  
2.6 Adding time stamps to recorded files  
Along with file creation and last-modified dates, many users want to record  
date and time information as data is received. Date and time stamps can be  
logged along with incoming data and triggered either when a specific data  
byte is received or when a gap in the data stream is detected.  
Date/time stamping is commonly used for ASCII (human-readable) text  
data. Lines of text end with a line feed character (ASCII code 10). Enable  
the SDR2-USB’s time stamping feature by adding the line Timestamp=1 to  
the setup file. Then, instruct the recorder to add a time stamp after a line  
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Configuring the DataBridge SDR2-USB  
SDR2-USB Configuration Guide rev 1.0  
feed is received by adding the line TimestampTrigger=10. The recorder will  
be “armed” to time stamp when a line feed is received, then insert a stamp  
when the next character is received— at the start of the next line.  
It is common to encounter a data source that periodically outputs “bursts” of  
data with time gaps between the bursts. For example, a GPS receiver  
outputs a position report once/second, then sits idle between reports. For  
this scenario, it is convenient to configure the recorder to insert a time stamp  
after any gap in the data stream. To specify this behavior, add the line  
TimeStampTrigger=gap to the setup file.  
Custom time/date stamp formats are also available and can include  
millisecond-precision stamping. See section 4.1.5 for more details on  
custom date/time stamps.  
2.7 Testing your configuration  
To test your configuration, use a null modem adapter or cable to connect a  
computer running terminal software (e.g. Windows HyperTerminal) to the  
SDR2-USB’s data port. Your computer then becomes a data source.  
Press the Record button to enter record mode. The SDR2-USB’s record  
indicator will illuminate.  
To ensure that recording is occurring, type several keystrokes on the  
terminal or use the software’s ASCII text upload feature to send a text file.  
The SDR2-USB’s data indicator should blink as you press keys, indicating  
data is being received. When finished, press the record button again to stop  
recording and inspect the file created on the USB storage device.  
Note: The SDR2-USB will not echo data while it is being recorded, so you  
will not see characters appear on-screen as you type. You can enable your  
terminal software’s "local echo" or "full duplex" feature to view data as you  
send it.  
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SDR2-USB Configuration Guide rev 1.0  
Operations  
3
3. Operations  
3.1 Setup file reading  
The setup.txt file on the USB storage device is read only when power is  
applied to the SDR2-USB. Once read, all settings found in setup.txt are  
retained by the recorder.  
3.2 Record mode operation  
When you press the record button, the SDR2-USB searches for the current  
file specified in the setup file, creates it if necessary, and opens it. Once the  
SDR2-USB has successfully opened the file, the record indicator turns on  
and the SDR2-USB enters record mode. Once in record mode, the SDR2-  
USB records any data received on the data port to the open file.  
3.2.1 Receiving data  
The data indicator flashes when the SDR2-USB receives data. This indicator  
is useful to ensure that the SDR2-USB is actually receiving data via the data  
port. Note: this flashing indicator does not guarantee a correct baud rate.  
Incorrect baud rates between the data source and SDR2-USB may still cause  
the data indicator to flash and invalid data to be written to the current file.  
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Operations  
SDR2-USB Configuration Guide rev 1.0  
3.2.2 Stopping recording  
Incoming data is written to the open file as it is received until you stop  
recording by pressing the record button. The SDR2-USB then closes the  
file, updates its directory entry (recording file size, date, and time), and  
returns to stop mode.  
3.2.3 Device removal while recording  
Do not terminate recording by removing the USB storage device without  
stopping the recorder, or disk corruption may occur.  
3.2.4 Power failure and improper shutdowns  
If the SDR2-USB loses power while in record mode, it returns to record  
mode after power is restored.  
An improper shutdown may result in loss of data (due to sector buffering  
and caching in the storage device) and minor allocation errors that can be  
repaired using the Windows 95/98/NT/2000/XP/Vista™ Explorer or  
chkdsk.exe from the Windows Command Prompt.  
3.2.5 Filename generation  
When operating with Append=0 (see section 4.1.3), unique new filenames  
are generated based on the specified filename. This is done to avoid  
overwriting an existing file within the specified folder.  
Filenames are generated by “incrementing”. Before incrementing, the file’s  
name is extended to 8 characters with a sequence of zeros. From there, the  
filename’s last character is incremented through the digits 0-9 and A-Z,  
carrying to the next-last as needed. An example of incrementing is shown in  
Figure 3.1.  
Before Incrementing  
BRIDGE.DAT  
After Incrementing  
BRIDGE01.DAT  
BRIDGE01.DAT  
BRIDGE02.DAT  
BRIDGE09.DAT  
BRIDGE0Z.DAT  
BRIDGE10.DAT  
BRIDGE0A.DAT  
BRIDGE10.DAT  
BRIDGE11.DAT  
Figure 3.1. Generating filenames when append mode is off.  
3.2.6 Full storage media  
When the storage media’s first valid partition is full, the SDR2-USB returns  
to stop mode unless overwrite-oldest mode is enabled, in which case the  
SDR2-USB will delete the oldest file in the target folder and return to  
recording mode.  
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SDR2-USB Configuration Guide rev 1.0  
Operations  
Delete files on the target media using your computer or replace the media,  
then insert and press the record button to record data normally.  
3.2.7 Formatting the storage media  
If you have purchased a USB storage device, you may need to format it  
using MS-DOS™, Windows 95/98/ME™, Windows NT/2000/XP™, or  
another operating system that supports the FAT file system.  
NOTE: If your USB  
storage media was  
included with  
SDR2-USB, it is  
already formatted  
properly.  
The SDR2-USB supports only the FAT and FAT32 file systems. If your  
computer supports the NTFS, HPFS, or other advanced file systems, be  
sure your card is formatted using FAT or FAT32.  
Figure 3.2. Formatting a small USB memory key using the FAT  
file system.  
3.2.8 Partitions  
In some cases, disks are partitioned to contain multiple "virtual" drives on a  
single disk. Partitioning is sometimes done to overcome the 2 gigabyte size  
limit in MS-DOS™ (and create multiple 2 gigabyte drives), support multiple  
operating systems and file systems, or make more efficient use of disk space.  
FDISK.EXE (included with MS-DOS™ and Windows 95/98™), Disk  
Administrator (included with Windows NT/2000/XP/Vista™), Norton Disk  
Doctor™, and Norton DiskEdit™ are useful tools for managing and  
analyzing disk partitioning schemes.  
The SDR2-USB supports both extended and primary FAT partitions, but  
always reads and writes files in the first partition it recognizes as a FAT  
partition.  
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Operations  
SDR2-USB Configuration Guide rev 1.0  
3.3 Lithium battery maintenance  
The SDR2-USB's real-time clock uses a small lithium battery to maintain  
time when external power is unavailable. The life of this battery should  
exceed 5 years.  
If you find your SDR2-USB is not keeping time correctly when power is lost,  
you may need to replace the battery. If necessary, replace the battery with a  
Panasonic CR2032, or equivalent, making sure the positive (+) face is in  
contact with the battery clip. After replacing the battery, be sure to reset the  
SDR2-USB’s time and date.  
3.4 Resetting to factory defaults  
The SDR2-USB can be reset to factory defaults by removing the USB  
storage device, holding the record button, and connecting power. Once  
power is connected, the record button must be held for 5 seconds until the  
flashing pattern is displayed on the front panel LEDs.  
Resetting to factory defaults overrides all settings that have been changed via  
the setup file.  
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SDR2-USB Configuration Guide rev 1.0  
Setup File Reference  
4
4. Setup File  
Reference  
All SDR2-USB configuration is performed via the setup.txt file in the root  
folder of the USB storage device. The setup file is read only when power is  
connected to the SDR2-USB, and all settings specified within the setup file  
are retained by the recorder indefinitely.  
4.1.1 Initial Setup Commands  
The CurrentDate= and CurrentTime= setup file lines are used during one-  
time initial setup to set the real-time clock’s time and date values. After  
including these lines in the setup file, power up the SDR2-USB and press  
the record button to synchronize the clock, then re-edit the setup file,  
erasing or commenting-out the lines for future use.  
CurrentDate: Use this command to set the real-time clock’s date. Date  
must be specified in YYYY/MM/DD format (e.g. 2009/06/30 for 30 June  
2009).  
CurrentTime: Use this command to set the real-time clock’s time. Time  
must be specified in 24-hour HH:MM:SS format (e.g. 14:49:00 for 2:49  
PM).  
// uncomment and update these 2 lines to set the time  
// time setting is synchronized on a button press  
CurrentDate=2009/06/30  
CurrentTime=14:49:00  
19  
 
Setup File Reference  
SDR2-USB Configuration Guide rev 1.0  
4.1.2 Data Port Setup Commands  
DataPortBaud (default=9600): Use this setup file command to specify a  
bits/second rate for communication with your data source. Industry-  
standard baud rates are 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600,  
115200, and 230400 bps. The SDR2-USB can also handle nonstandard  
rates including 460800 and 961600 bps.  
DataPortWordFormat (default=8N1): This command changes the  
SDR2-USB’s data bits, parity, and stop bits. To specify the most common  
setting, set this value to “8N1”, meaning eight data bits, no parity, and one  
stop bit. Other possible values include seven data bits, odd/even parity  
(O/E), and one or two stop bits, resulting in the following permutations:  
8N1,8N2,7E1,7E2,7O1,7O2,8E1,8O1.  
DataPortHandshake (default=0): Use this setup file command to turn  
hardware handshaking on or off. When enabled, the SDR2-USB will drive  
its RTS signal low when the USB media isn’t present and internal data  
buffer space is exhausted. When disabled, the RTS signal will remain high  
regardless of the SDR2-USB’s state.  
// data port baud rate (50-921600)  
DataPortBaud=9600  
// data port word format (8 data bits, no parity, 1 stop bit)  
DataPortWordFormat=8N1  
// data port handshaking (0=off)  
DataPortHandshake=0  
4.1.3 Recording Behavior Commands  
Filename (default=DATA\SDR-0000.DAT): The Filename command sets  
both the location and name of the file to be recorded. To specify a folder  
for data storage (recommended), precede the filename with a folder name  
and backslash. To record files to the media’s root folder, simply specify a  
filename. The SDR2-USB uses this filename for the first file that’s  
recorded— subsequent files are given unique names based on this name.  
Append (default=0): Use the Append command to control whether the  
SDR2-USB creates new files each time recording restarts. When  
Append=1, the SDR2-USB adds data to the existing file. When  
Append=0, the SDR2-USB creates a new file with unique filename any time  
recording starts (see section 3.2.5).  
FlushBuffer (default=0): Use the FlushBuffer command with a value of 1 to  
configure the SDR2-USB to record only data that is received after recording  
starts. When FlushBuffer is 0, the recorder can buffer several seconds of  
data while recording is stopped, allowing time to exchange media if needed.  
ForceRecording (default=0): ForceRecording=1 configures the SDR2-USB  
to always record if storage media is present and ignore the front-panel  
button. This setting is useful for guaranteeing data is recorded.  
OverWriteOldest (default=0): Use OverWriteOldest=1 to configure the  
SDR2-USB to overwrite the oldest file in the destination recording folder if  
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SDR2-USB Configuration Guide rev 1.0  
Setup File Reference  
possible when space available on the storage media is exhausted. Together  
with scheduled file closing, this option can be used to configure the  
SDR2-USB as a circular buffer— as the disk fills, the oldest file is  
overwritten.  
// file name and path to record to  
Filename=DATA\GPS0000.txt  
// create new files when recording starts  
Append=0  
// buffer data when stopped  
FlushBuffer=0  
// always record if media is present  
ForceRecording=1  
// overwrite oldest file if necessary  
OverWriteOldest=1  
4.1.4 Scheduled File Closing Commands  
Scheduled file closing, together with Append=0, allows the user to divide  
recorded data into files of a more manageable size.  
FileClose (default=0): The FileClose setup file line enables and disables  
scheduled file closing.  
FileCloseSeconds: The FileCloseSeconds setting configures the SDR2-USB  
to close the current file and restart recording after the specified number of  
seconds. For example, to configure the recorder to restart recording every  
hour, use FileCloseSeconds=3600 (3600 seconds=60 minutes=1 hour).  
FileCloseBytes: The FileCloseBytes setup file line configures the recorder to  
close the current file and restart recording once the current file reaches the  
specified number of bytes. For example, use FileCloseBytes=1048576 to  
configure the SDR2-USB to create a new file if the size reaches 1 megabyte.  
StartTime, StopTime: The StartTime and StopTime lines configure the  
recorder to start and stop at specific times of day (specified in 24-hour  
HH:MM:SS format). If start and stop times are equal, each file will contain  
24 hours of data. FlushBuffer=1 (see above) is usually used if start and stop  
times are different in order to reject data received while recording was  
stopped.  
// enable scheduled file closing  
FileClose=1  
// record only during business hours  
StartTime=08:00:00  
StopTime=17:00:00  
FlushBuffer=1  
4.1.5 Time Stamping Commands  
The SDR2-USB can insert time and date information into files during  
recording. Among other things, this is useful for scientific data analysis and  
historical trending studies.  
Timestamp (default=0): The Timestamp setup file line enables date/time  
stamping.  
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Setup File Reference  
SDR2-USB Configuration Guide rev 1.0  
TimestampTrigger: The TimestampTrigger setup file line specifies a decimal  
ASCII character that “arms” the time stamping function. Once the trigger  
character is received, the recorder will insert a time stamp when the next  
byte of data is received. For example, a trigger value of 10 will configure the  
SDR2-USB to insert a time stamp after a line feed is received.  
TimestampTrigger=gap: Specifying a trigger value of “gap” enables a special  
time stamping mode where the SDR2-USB will detect time gaps in the  
stream of incoming serial characters and insert a time stamp after the gap.  
This is useful for data sources such as GPS receivers that output “bursts” of  
data periodically.  
TimestampFormat (default=MM/DD/YYYY hh:mm:ss\20): Use the  
TimestampFormat command to provide a template for the timestamps as  
they are inserted into the file. Timestamp field format values are case-  
sensitive— month, day, and year fields must be specified in capital letters,  
while hour, minute, second, and millisecond fields must be provided in  
lower-case letters. Escape codes are used to insert characters such as spaces,  
line feeds, carriage returns, and tabs. To include an escape sequence, use a  
backslash followed by the two-digit hexadecimal ASCII code for the  
character to use (e.g. \0A for a line feed or \20 for a space).  
// enabled time stamping  
Timestamp=1  
// trigger on a line feed  
TimestampTrigger=10  
// include milliseconds and 2-digit year in time/date stamp  
TimestampFormat=MM/DD/YY hh:mm:ss.ddd\20  
4.1.6 Other Commands  
DisableIndicators (default=0): Use a setup file line with  
DisableIndicators=1 to turn front-panel LED indicators off. When  
enabled, the indicators will flash occasionally in a “heartbeat” pattern. Use  
this setting to save small amount of power and/or avoid user confusion.  
22  
 
SDR2-USB Configuration Guide rev 1.0  
J4 Remote Control Port  
5
5. J4 Remote  
Control Port  
5.1 Overview  
The SDR2-USB’s J4 remote connector allows for starting and stopping  
recording via external switches/buttons or TTL/CMOS digital logic. The J4  
connector also provides alternate outputs for the front-panel fault, data, and  
record indicators.  
5.2 Location  
The J4 connector is located next to the J1 power input connector on the  
SDR2-USB’s internal circuit board.  
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Setup File Reference  
SDR2-USB Configuration Guide rev 1.0  
5.3 Functions  
Table 5.1 describes the functions of the J4 remote connector.  
VDD (3.3VDC)  
Regulated low-current voltage output. Use for deasserting  
active-low inputs and driving LED indicator outputs.  
GND (0 VDC)  
Signal ground. Use for asserting active-low inputs.  
Momentary record input. Function is similar to front-panel  
record button. To use, connect a momentary pushbutton  
switch between this contact and GND.  
REC_BUTTON  
Force-record input. To use, connect a toggle switch  
between this contact and GND. When closed, the  
SDR2-USB will always enter record mode.  
REC_TOGGLE  
FAULT  
Fault condition indicator output. Function is similar to the  
front-panel Fault indicator. When low, indicates an  
unrecoverable error has occurred in the SDR2-USB. To  
use, connect an LED’s cathode to this contact and its anode  
to VDD via a current-limiting resistor. Limit current to 10 mA  
max.  
Data indicator output. Function is similar to the front-panel  
Data indicator. Pulses momentarily low to indicate data  
reception in the SDR2-USB. To use, connect an LED’s  
cathode to this contact and its anode to VDD via a current-  
limiting resistor. Limit current to 10 mA max.  
DATA  
Recording indicator output. Function is similar to the front-  
panel Record indicator. Driven low when the SDR2-USB is  
recording data to an open file. To use, connect an LED’s  
cathode to this contact and its anode to VDD via a current-  
limiting resistor. Limit current to 10 mA max.  
RECORD  
Table 5.1. J4 remote control port pin functions.  
5.4 Pinout and Mating Cable  
The J4 connector is a 2mm 10-pin connector housing that mates to a Hirose  
DF11-10DS-2C shell (Digi-Key part number H2023-ND). A pre-built J4  
cable is available from Acumen Instruments Corporation on request.  
24  
 
SDR2-USB Configuration Guide rev 1.0  
J4 Remote Control Port  
Contact  
1
Function  
Direction  
Wire Color  
VDD (3.3 VDC)  
GND (0 VDC)  
-
Black  
Blue  
Grey  
Yellow  
-
2
3
REC_BUTTON  
REC_TOGGLE  
FAULT  
input  
input  
4
5
output  
6
no connect  
DATA  
7
output  
output  
Orange  
Green  
-
RECORD  
8
9
VDD (3.3 VDC)  
GND (0 VDC)  
10  
-
Table 5.2. J4 remote control port pinout.  
J4 mating plug (shell): Hirose DF11-10DS-2C (Digi-Key part number  
H2023-ND)  
For use with DF11 crimp contacts e.g. DF11-2428SCA (Digi-Key part number  
H2300-ND) or pre-crimped wires (Digi-Key part number H3BXG-101LL-CW  
where LL=length in inches, C=color code, W=wire gauge code).  
5.5 Force-Record Shunt Installation  
The SDR2-USB can be forced into record mode any time power is applied  
and USB storage is present. To use this mode, install a 2mm shunt between  
J4 pins 4 (REC_TOGGLE) and pin 2 (GND).  
A good choice of shunt is Norcomp part number 810-002-SP2L001 (Digi-  
Key part number SP2-001E-ND).  
25  
 
 
SDR2-USB Configuration Guide rev 1.0  
Service and Support  
6
6. Service and  
Support  
6.1 Exception Codes  
The following are common error codes encountered when using DataBridge  
SDR2-USB products. To determine which error has occurred, watch the  
"exception" indicator on the SDR2-USB's front panel and count the number  
of rapid blinks. Each sequence is separated by a 1 second pause in the blink  
pattern.  
Exception 2: Root Directory Full  
A FAT (FAT16) root directory can have only 512 directory entries (fewer if  
long filenames are used). Delete files from the root directory, record to a  
subfolder in the root directory, or use FAT32 formatting to overcome this  
limitation.  
Exception 3: Disk Full  
The disk has no (or almost no) available space for files. Delete files from the  
disk to ensure space is available.  
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Service and Support  
SDR2-USB Configuration Guide rev 1.0  
Exception 4: Bad Boot Record  
Occurs when the disk is completely unformatted or formatted for an  
unsupported file system.  
Use format /FS:FATfrom the Windows command prompt to ensure  
proper FAT formatting.  
Exception 5: Hardware Error  
Usually occurs when the SDR2-USB cannot reset the USB storage device.  
Try ejecting and reinserting the card or using a new card and contact  
Acumen if problem persists.  
Exception 6: EEPROM Error  
Rare hardware error. Contact Acumen to discuss repair or replacement.  
Exception 7: Cache Error  
Rare hardware error. Contact Acumen to discuss repair or replacement.  
Exception 8: Buffer Error (firmware error)  
Rare error that may occur in customized or beta firmware versions. Contact  
Acumen to report.  
Exception 9: Tasking Error (firmware error)  
Rare error that may occur in customized or beta firmware versions. Contact  
Acumen to report.  
Exception 10: USB Error  
The USB storage media has reported a fatal error to the SDR2-USB.  
Reinsert/replace the media and contact Acumen if problem persists.  
Exception 11: Directory Creation Error  
Rare. The SDR2-USB cannot create the subdirectory files are to be  
recorded to. Try using a different directory name or reformatting the media.  
Exception 12: FAT12 File System Detected  
The SDR2-USB has determined that the USB media was formatted using  
the FAT12 file system, which is unsupported. Reformat the USB storage  
device using the /A:512 option (Windows 2000/XP) and retry.  
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SDR2-USB Configuration Guide rev 1.0  
Service and Support  
6.2 Contacting Acumen Instruments  
Corporation  
6.2.1 Technical support  
Service and technical support can be reached between the hours of 9AM and  
5PM (Central Standard Time) Monday through Friday. Acumen Instruments  
Corporation can be reached at the following phone numbers:  
(515) 296-5366 (voice)  
(515) 296-3554 (fax)  
6.2.2 U.S. Mail  
Acumen Instruments Corporation can be reached by mail at:  
Acumen Instruments Corporation  
2625 N. Loop Drive Suite 2200  
Ames, IA 50010  
USA  
6.2.3 E-mail  
Acumen Instruments Corporation can be reached via e-mail at:  
6.2.4 World Wide Web  
Acumen Instruments Corporation maintains a web site containing product  
information and downloads:  
6.3 Returning Equipment  
Before returning equipment to Acumen Instruments Corporation, please call  
for an RMA number and shipping information. This allows us to plan for  
your shipment in order to provide the best possible service. When returning  
equipment, please include a note indicating the symptoms of the failure and  
any other pertinent information.  
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Service and Support  
SDR2-USB Configuration Guide rev 1.0  
6.4 Warranty  
6.4.1 One year warranty  
Acumen Instruments Corporation warrants this product to be free from  
defects in materials and workmanship for a period of one (1) year from the  
date of shipment. During the warranty period, Acumen Instruments  
Corporation will, at its option, either repair or replace products that prove to  
be defective.  
6.4.2 Exclusions  
This warranty shall not apply to any defect, failure or damage caused by  
misuse, abuse, improper application, alteration, accident, disaster,  
negligence, use outside of the environmental specifications, improper or  
inadequate maintenance, or incorrect repair or servicing not performed or  
authorized by Acumen Instruments Corporation.  
6.4.3 Limitations  
ACUMEN INSTRUMENTS CORPORATION SHALL IN NO EVENT HAVE  
OBLIGATIONS OR LIABILITIES TO BUYER OR ANY OTHER PERSON FOR LOSS  
OF PROFITS, LOSS OF USE OR INCIDENTAL, SPECIAL, OR CONSEQUENTIAL  
DAMAGES, WHETHER BASED ON CONTRACT, TORT (INCLUDING  
NEGLIGENCE), STRICT LIABILITY, OR ANY OTHER THEORY OR FORM OF  
ACTION, EVEN IF ACUMEN INSTRUMENTS CORPORATION HAS BEEN ADVISED  
OF THE POSSIBILITY THEREOF, ARISING OUT OF OR IN CONNECTION WITH  
THE SALE, DELIVERY, USE, REPAIR, OR PERFORMANCE OF THIS PRODUCT  
(INCLUDING EQUIPMENT, DOCUMENTATION AND SOFTWARE). IN NO EVENT  
SHALL THE LIABILITY OF ACUMEN INSTRUMENTS CORPORATION ARISING IN  
CONNECTION WITH ANY PRODUCT EXCEED THE ACTUAL AMOUNT PAID FOR  
SUCH A PRODUCT.  
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, WRITTEN OR ORAL,  
EXPRESSED OR IMPLIED, INCLUDING IMPLIED WARRANTIES OR  
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
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SDR2-USB Configuration Guide rev 1.0  
Serial Port Basics  
A
A.Serial Port  
Basics  
A.1 Serial specifications  
Serial data is any data that is sent one bit at a time using a single electrical  
signal. In contrast, parallel data is sent 8, 16, 32, or even 64 bits at a time  
using a signal line for each bit. Data that is sent without the use of a master  
clock is said to be asynchronous serial data.  
Several communications standards exist for the transfer of asynchronous  
serial data. Common PC’s transfer data using the EIA RS-232C (also known  
as V.28 or V.24). Updated versions of this standard include RS-232D and  
EIA/TIA-232E, but most literature still refers to the RS-232C or RS-232  
standard.  
Other asynchronous serial standards in common use include RS-422, RS-  
423, and RS-485. These standards allow higher data rates and longer cable  
lengths than RS-232 and are common in industrial settings.  
A.2 Data rates  
The baud rate for a serial connection is the number of bits that are  
transmitted per second. It is specified in bits/second or baud. For example, a  
9600 baud serial link transfers 9600 bits per second.  
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SDR2-USB Configuration Guide rev 1.0  
The EIA RS-232C standard permits data rates up to 19200 bps and cable  
lengths up to 400 meters (but not both).  
data rate  
(bps)  
19200  
9600  
maximum distance  
(meters)  
(feet)  
15  
45  
25  
50  
76  
152  
4800  
2400  
1200  
600  
100  
200  
400  
304  
608  
1216  
Table A.1. Data rates and distances for RS-232 communications.  
Although the specification only defines rates up to 19200 bps,  
communication using data rates as high as 230400 bps and a short (<2  
meter) cable are common. Standard modems communicate with computers  
at up to 115200 bps.  
As you may have guessed, the use of high baud rates requires more capable  
computer hardware. At high baud rates, a computer must process as many as  
23000 characters per second. The constant attention a computer must pay to  
its serial port makes this problematic particularly in multitasking  
environments such as Microsoft Windows 3.1/95/98/NT/2000.  
A.2.1 Data rates and the UART  
Computer hardware designers solve this problem by allowing the computer  
to respond to characters less frequently. A Universal Asynchronous  
Receiver/Transmitter (UART), the component responsible for  
communicating via RS-232, may contain several bytes of memory called a  
FIFO (first-in, first-out memory).  
The original IBM PC (and many of its successors) used the 8250 UART,  
which contained no FIFO. That is, a computer with 8250 (or 16450)  
UART’s must respond to every incoming character.  
Newer PC’s incorporate the 16550 UART or a variant. The 16550  
incorporates a 16-byte FIFO and is mandatory for communications at  
speeds above 9600 bps and is important for error-free communications at  
lower speeds as well.  
You can find out which type of UART’s your computer uses by using the  
MSD.EXE tool provided with DOS and Windows or by looking in the  
Windows 95/98 control panel.  
A.3 More asynchronous serial parameters  
In most cases, the data rate in bytes/second can be approximated by dividing  
the baud rate (in bits/second) by 10. If a byte consists of 8 bits, why divide  
by 10?  
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Serial Port Basics  
To transfer data asynchronously, the UART frames the 8 data bits between a  
stop bit and a start bit. The start bit is always a zero, while the stop bit is  
always a one. So, a byte of data sent serially is made up of 10 bits instead of  
the usual 8.  
Asynchronous serial devices can communicate using 7 or 8 data bits, and 1,  
1½, or 2 stop bits. To further complicate matters, devices can also employ a  
parity bit instead of an eighth data bit to check for errors. Even parity  
systems transmit a one when the sum of the seven bits is an even number,  
while odd parity systems transmit a one when the sum is odd. Still more  
exotic systems may specify “mark” or “space” parity, where the parity bit is  
always a one or zero, respectively.  
What does all of this mean? Device vendors usually specify their data rate  
and format using statements like “9600, 8N1”, which translates to 9600 bps,  
8 data bits, no parity, and 1 stop bit or “19200, 7E1”, which translates to  
19200 bps, 7 data bits, even parity, and 1 stop bit.  
NOTE: Most serial  
devices format of eight  
data bits, no parity,  
and one stop bit  
(8N1).  
A.3.2 DTE and DCE  
The RS-232 specification defines two classes of devices: data terminal  
equipment (DTE) and data communication equipment (DCE). Your  
computer’s serial port is configured for DTE operation, since the computer  
acts as a terminal. Modems and many other serial devices are configured as  
DCE, since they are communications equipment.  
What’s the difference? A DTE device’s TD signal means “I transmit data on  
this line.” A DCE’s TD signal can be read “You (the DTE) transmit data to  
me on this line.” A DTE’s RD signal means “I receive data on this signal  
line.” A DCE’s RD line means, “You, the DTE, will receive the data I  
transmit on this signal line.” Sound confusing?  
A look at a the DB9 connector pinouts and signal direction with respect to  
DTE (e.g. your computer) makes things a little more clear.  
pin number  
signal name  
transmitted data  
received data  
request to send  
clear to send  
data terminal ready  
data set ready  
data carrier detect  
ring indicator  
25-pin  
2
3
4
5
20  
6
8
22  
7
9-pin  
direction  
DTEDCE  
DTEDCE  
DTEDCE  
DTEDCE  
DTEDCE  
DTEDCE  
DTEDCE  
DTEDCE  
3
2
7
8
4
6
1
9
5
TD  
RD  
RTS  
CTS  
DTR  
DSR  
DCD  
RI  
signal ground  
GND  
Table A.2. Pinouts for 9-pin and 25-pin serial connectors.  
The cable that connects DTE devices (such as your computer) and DCE  
devices (such as your modem) is simple. It connects the TD pin to TD, pin  
RD to RD, etc. A cable that connects DTE to DTE or DCE to DCE must  
connect the TD to RD and RD to TD. This cable is referred to as a null  
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SDR2-USB Configuration Guide rev 1.0  
modem cable because it can connect two terminals (DTE’s) without the use  
of modems (DCE’s). Note that GND pins are always connected.  
Most devices have female connectors (DB9 or DB25) if they are configured  
for DCE operation and male connectors if they are configured for DTE  
operation, but this is not always the case.  
There is a simple trick for determining whether a device is DTE or DCE.  
Connect a voltmeter’s ground line to the connector’s GND pin. Then, probe  
the voltage on the TD and RD pins. If the TD pin voltage is small (-  
3V<Vin<+3V), the device is configured to receive data on the TD pin, and  
thus is a DCE device. Likewise, if the RD pin voltage is small, the device is  
receiving data on the RD pin, and thus is DTE.  
A.3.3 Handshaking  
Handshaking signals by the receiving device to tell the transmitter “I am  
ready for data” or “I am not ready for data.” These signals are optional: the  
receiver may always be ready for data or may choose to simply discard data it  
couldn’t process.  
A DTE device asserts the “request to send” (RTS) signal when it is ready to  
receive data and deasserts it when it cannot accept data. Likewise, a DCE  
device asserts “clear to send” (CTS) when it is ready to receive data. The  
RTS and CTS signals form a handshaking pair, and their use constitutes  
RTS/CTS handshaking.  
The “data terminal ready” (DTR) signal, asserted by the DTE, and the “data  
set ready” (DSR) signal, asserted by the DCE serve similar functions and  
constitute DTR/DSR handshaking. A DTE or DCE devices may employ  
either or both forms of handshaking. Often, deasserting RTS or CTS signals  
“micro” events, such as a buffer that is full but will be empty soon, while  
deasserting DTR or DSR may signal “major” events such as that power has  
not been applied.  
RTS/CTS handshaking and DTR/DSR handshaking are both referred to as  
hardware handshaking. Another form of handshaking, XON/XOFF or  
software handshaking, requires that the receiver send a character (Control-S,  
ASCII 19) to halt data transfer and another character (Control-Q, ASCII  
17) to resume transfer. Although this method eliminates the need for the  
RTS, CTS, DTR, or DSR signals, it suffers from slow response time by the  
receiver and renders 2 characters of the 256-character ASCII set unusable.  
A.3.4 Voltage levels  
For noise immunity and long cable lengths, RS-232 devices convert  
TTL/CMOS-level signals (0V=logic zero, +5V or +3.3V=logic one) to  
higher voltage bipolar signals. For the TD and RD signal lines, RS-232  
devices use a voltage between –3V and –25V to transmit a one and a voltage  
between +3V and +25V to transmit a zero. For the other signal lines (RTS,  
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SDR2-USB Configuration Guide rev 1.0  
Serial Port Basics  
CTS, etc.), RS-232 devices use +3V to +25V to assert the signal and –3V to  
–25V to deassert the signal. These voltage levels are defined in the EIA/TIA-  
232E specification. So, when a DTE devices drives RTS at –9.50V, it is  
signaling the DCE to stop sending data.  
A few devices, particularly devices that communicate at low data rates or  
over short cables, bypass the voltage conversion altogether. These devices  
often require “computer interface kits” that are really no more than a level  
converter in a box. These serial ports are often referred to as TTL RS-232,  
CMOS RS-232, or 5 Volt RS-232 ports and require level converters to  
interact with computers and other serial devices.  
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Specifications  
SDR2-USB Configuration Guide rev 1.0  
B
B.Specifications  
B.1 Electrical specifications  
SDR2-USB requires a 5 to 30 VDC power source power source via  
connectors J7 and J1 on SDR2-USB. J1 is inaccessible on the SDR2-USB  
without removing the enclosure.  
NOTE: The  
SDR2-USB datasheet  
contains further  
specifications. All  
specifications shown in  
this section may be  
superseded by the  
datasheet.  
Recording Mode  
Idle  
+12 VDC  
+12 VDC  
see data  
sheet  
Table B.1. DataBridge SDR2-USB power consumption with  
Kingston 1GB USB flash key installed.  
B.1.5 J7 rear power receptacle pin configuration  
pin Function  
tip +5 to +30 VDC  
ring Ground  
Table B.2. The SDR2-USB rear power receptacle pin configuration.  
37  
 
Specifications  
SDR2-USB Configuration Guide rev 1.0  
B.1.6 J1 power receptacle pin configuration  
pin Function  
1
2
+5.0 to +30 VDC  
Ground  
Table B.3. The SDR2-USB internal power receptacle pin  
configuration.  
B.2 Serial communications  
Serial Port  
electrical interface compliance  
data rates  
data bits  
EIA/TIA-232E and V.28  
50 to 921600 baud  
7 or 8  
stop bits  
1 or 2  
Parity  
Handshaking  
None, even, odd  
RTS/CTS, none  
Table B.4. Serial communications specifications for the  
SDR2-USB.  
B.3 USB socket  
Socket Type  
USB "A" receptacle  
storage capacity  
limited only by storage device and file system  
Table B.5. USB socket specifications for the SDR2-USB.  
B.4 Mechanical Specifications  
SDR2-USB  
Dimensions  
3.35" L x 3.76" W x 1.18" H  
(85 mm x 96 mm x 30 mm)  
8.0 oz (225.0 grams)  
Aluminum extrusion  
Weight (without USB media)  
Enclosure Material  
Table B.1. SDR2-USB mechanical specifications.  
38  
 
Specifications  
SDR2-USB Configuration Guide rev 1.0  
Notes:  
39  
 

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