SeaLINK+8.Ultra Users Manual
Contents
1. 5 LINUX DEVICE DRIVER INSTALLATION cccccccccecececscececececscececececscececececececececececececececececeeecececesececess 6 RAW SOCKETS iet ueri be ee eee ENTE INS 6 TECHNICAE DESCRIPTION eee CONNECTOR PIN 5 5 enin ense sese sese se ease ease ease see r ease ene en 7 RS 422 485 DB 9 Male RERO E 7 RS 232 DB 9 Mal eerte ere ede e 7 8 20 sees deae ee Sos 9 ENVIRONMENTAL SPECIFICATIONS 2 2 4 sese sre r eren ein 8 MANUFACTURING i TIPP I 8 APPENDIX TROUBLESHOOTING ee ee ee eese eese eese eese eese eese eese eese eese eese APPENDIX HOW TO GET ASSISTANCE 22 22 2 APPENDIX ELECTRICAL INTERFACE sn sees sesso sssssssssssss APPENDIX D ASYNCHRONOUS COMMUNICATIONS eese eese eese eese eesee2. RTS Request To Send Positive 6 Output CTS Clear Send Positive 9 Input CTS Clear To Send Negative 8 Input RS 232 DB 9 Male GND Grund 15 Data Carrier Detect Ring Indicator RD 8 DSR DataSetReady 6 hm Technical Note Please terminate any control signals that are not going to be used The most common way to do this is connect RTS to CTS and RI Also connect DCD to DTR and DSR Terminating these pins if not used will help ensure you get the best performance from your adapter Sealevel Systems SeaLink 8 Ultra Page 7 Specifications Specifications Environmental Specifications Specification Operating Temperature 0 to 70 C 50 to 105 C Range 32 to 158 58 to 221 F Humidity Range 10 to 9096 R H 10 to 9096 R H Non Condensing Non Condensing Manufacturing Sealevel Systems Printed Circuit boards are built to UL 94V0 rating and are 100 electrically tested These printed circuit boards are solder mask over bare copper or solder mask over tin nickel Sealevel Systems SeaLink 8 Ultra Page 8 Appendix A Troubleshooting Appendix A Troubleshooting Sealevel Software is supplied with the Sealevel Systems adapter and will be used in the troubleshooting procedures Using this software and following these simple steps can eliminate most common problems without the need to call Techni
3. Always use the Sealevel Systems diagnostic software when troubleshooting a problem This will eliminate any software issues from the equation If you are unable to resolve the problem contact Technical Support at mailto support sealevel com Sealevel Systems SeaLink 8 Ultra Page 9 Appendix B How to Get Assistance Appendix B How To Get Assistance Please refer to Troubleshooting Guide prior to calling Technical Support 1 Begin by reading through the Trouble Shooting Guide in Appendix A If assistance is still needed please see below 2 When calling for technical assistance please have your user manual and current adapter settings If possible please have the adapter installed in a computer ready to run diagnostics 3 Sealevel Systems provides an FAQ section on its web site Please refer to this to answer many common questions This section can be found at http www sealevel com faq asp 4 Sealevel Systems maintains a web page on the Internet Our home page address is http www sealevel com The latest software updates and newest manuals are available via our web site 5 Technical support is available Monday to Friday from 8 00 a m to 5 00 p m eastern time Technical support can be reached at 864 843 4343 Return Authorization Must Be Obtained From Sealevel Systems Before Returned Merchandise Will Be Accepted Authorization Can Be Obtained By Calling Sealevel Systems And Requesting A Return Merchandi
4. Authenticode signature not found Please select the Yes button and proceed with the installation This declaration simply means that the Operating System is not aware of the driver being loaded It will not cause any harm to your system 8 During setup the user may specify installation directories and other preferred configurations This program also adds entries to the system registry that are necessary for specifying the operating parameters for each driver An uninstall option is also available to remove all registry INI file entries from the system Linux If you have downloaded the source code in tar gz format type tar xzvf filename tar gz to extract the files and refer to the INSTALL file in the extracted directory If you have downloaded an RPM file compatible with your system type rpm filename rpm to install the software Locating the Device and Assigning an IP Address Before the SeaLINK device can be used it must be assigned an IP address valid to your network When first powered up the device will attempt to automatically find an IP address using DHCP If the device is linked but cannot locate a DHCP server the link LED on the box will flash indicating that the device does not have valid network setting In that case you will need to assign it a static address using the configuration utility provided The configuration utility Start Programs SeaLINK SeaLINKConfig exe is also useful for locating devices to determi
5. created can communicate with the serial server at the specified IP address and port number Once the Status returns a series of green checkmarks indicating a working configuration click the Use Settings button and proceed to the last step of setting up your applications Use WinSSD to verify that the COM ports a re configured correctly and fully functional See the Installation chapter in the User s Guide if you need more information Reconfigure your applications to use remote devices or SeaLINK COM ports Change your application settings to use a previously installed SeaLINK COM port Your application can now be used over a Windows TCP IP network Sealevel Systems SeaLink 8 Ultra Page 5 Software Installation Linux Device Driver Installation The source code is in tar gz format type tar xzvf filename tar gz to extract the files and refer to the INSTALL file in the extracted directory If you have downloaded an RPM file compatible with your system type rpm i filename rpm to install the software To implement a virtual serial port in Linux use the SeaLINK virtual serial port module provided in the software installation 1 Configuration e Before you can access a serial port you must install it to the client computer Launch the SeaLINK Configuration console utility by typing usr sbin sealinkcfg If your device is on the local network you should see it listed Type i followed by the number of the hub in the
6. forth The data will not be inspected or modified in any way This method provides the least control because serial port functions such as baud rate and modem control signals cannot be monitored or changed programmatically However Raw Data is platform independent and requires no software installation If your purposes do not require dynamic serial port control Raw Data may be the most efficient choice for you 1 Configuration e Since Raw Data does not allow for programmatic changing of serial port controls the serial ports must be configured before use via the onboard web server see the section Web Configuration From the Port Settings page configure the ports to the desired settings and click Submit at the bottom of the page The serial ports will automatically be set to these defaults when opened Selection 2 Usage Details access a serial port using Raw Data mode open a TCP socket to the device s IP address on port 4760 which corresponds to the serial port on the device Only one client can open each serial port at a time further socket requests to a TCP port will be denied Sealevel Systems SeaLink 8 Ultra Page 6 Technical Description Technical Description The Sealevel Systems SEALINK 4 Ultra provides a PCI interface adapter with 8 RS 232 422 485 asynchronous serial ports for industrial automation and control applications Connector Pin Assignments RS 422 485 DB 9 Male GND Ground 1 1 0 5
7. 20 Ohm termination resistor across the input data pins RX RX as well as the pull up and pull down resistors may be removed or inserted with DIP switches S1 S4 To add the termination bias resistors select the On position to remove it select the position Sealevel Systems SeaLink 8 Ultra Page 2 Software Installation Software Installation Unlike most other adapters the SeaLINK 8 Ultra may physically be connected before the software has been installed To completely install the adapter attach a 10 100 Base T Ethernet cable to the appropriate connector make the connections for your serial port and connect the provided AC adapter or provide 5 VDC at 1A Windows 98 ME NT 2000 XP Start Windows 2 Insert the Sealevel Systems CD in to your CD drive 3 If Auto Start is enabled for this drive the software will automatically launch Otherwise point your browser to the Index htm on the root directory of the CD 4 Select Install Software 5 Select the Part Number for your adapter from the listing 6 Select Windows 98 ME 2000 XP The setup file will automatically detect the operating environment and install the proper components Next depending on the OS version select the Run this program from its current location or Open option Follow the information presented on the screens that follow 7 A screen may appear with the declaration The publisher cannot be determined due to the problems below
8. SEALEVEL SYSTEMS INCORPORATED SeaLINK 8 Ultra Users Manual Part 4803 Sealevel Systems Inc Telephone 864 843 4343 155 Technology Place Fax 864 843 3067 Liberty SC 29657 USA www sealevel com Contents OVER VIE Ws Lc REI E MR 1 WHAT oenielobenPE D Semet scm ib emat eani ee 1 CARD SETUP 5 esee o Soot aene Se ee be sra eae Ga gene de gd os hene ose aede ge SF ae Gods ae asa 2 ELECTRICAL INTERFACE 5 seroso enne seen seen eese se eren eese eese en een 2 RS 485 BNABEE MOBES 1 reiten t eee pes ds ee RENE S 2 SOFTWARE INSTALLATI N gt DEVICE CONFIGURATION WITH WINDOWS cccccececesececececececececececececececececececececececeeececeeeeseeeececeeececs 3 DEVICE CONFIGURATION WITH LINUX ccccccccccecececececececececececececececececececscecececececeeececeeeeececececececeeecs 4 WEB CONFIGURATION E 4 D M 4 GUSTOM BAUD RATES ies nito hiemis teile ieri eer elabi ENEE 4 RESETTING TO FACTORY DEFAULTS sssssccvcvvvevessvevecevsvevcvessvevesevevevevevevevesevsvevsvevsvevssevevevevevevevevevss 4 WINDOWS DEVICE DRIVER
9. anty that is standard on all Sealevel manufactured products We are able to offer this warranty due to our control of manufacturing quality and the historically high reliability of our products in the field Sealevel products are designed and manufactured at its Liberty South Carolina facility allowing direct control over product development production burn in and testing Sealevel Systems Inc hereafter Sealevel warrants that the Product shall conform to and perform in accordance with published technical specifications and shall be free of defects in materials and workmanship for life In the event of failure Sealevel will repair or replace the product at Sealevel s sole discretion Failures resulting from misapplication or misuse of the Product failure to adhere to any specifications or instructions or failure resulting from neglect or abuse are not covered under this warranty Warranty service is obtained by delivering the Product to Sealevel and providing proof of purchase Return authorization must be obtained from Sealevel Systems before returned merchandise will be accepted Authorization is obtained by calling Sealevel Systems and requesting a Return Merchandise Authorization RMA number The Customer agrees to insure the Product or assume the risk of loss or damage in transit to prepay shipping charges to Sealevel and to use the original shipping container or equivalent Warranty is valid only for original purch
10. aser and is not transferable Sealevel Systems assumes no liability for any damages lost profits lost savings or any other incidental or consequential damage resulting from the use misuse of or inability to use this product Sealevel Systems will not be liable for any claim made by any other related party This warranty applies to Sealevel manufactured Product Product purchased through Sealevel but manufactured by a third party will retain the original manufacturer s warranty Sealevel Systems Incorporated 155 Technology Place P O Box 830 Liberty SC 29657 USA 864 843 4343 FAX 864 843 3067 www sealevel com email support sealevel com Technical Support is available from 8 a m to 5 p m Eastern time Monday Friday Trademarks Sealevel Systems Incorporated acknowledges that all trademarks referenced in this manual are the service mark trademark or registered trademark of the respective company SEALINK 8 ULTRA is a trademark of Sealevel Systems Incorporated Sealevel Systems SeaLink 8 Ultra Page 15
11. at assembles the bits back into a character Data rate error checking handshaking and character framing start stop bits are pre defined and must correspond at both the transmitting and receiving ends Asynchronous communications is the standard means of serial data communication for PC compatibles and PS 2 computers The original PC was equipped with a communication or COM port that was designed around an 8250 Universal Asynchronous Receiver Transmitter UART This device allows asynchronous serial data to be transferred through a simple and straightforward programming interface A start bit followed by a pre defined number of data bits 5 6 7 or 8 defines character boundaries for asynchronous communications The end of the character is defined by the transmission of a pre defined number of stop bits usually 1 1 5 or 2 An extra bit used for error detection is often appended before the stop bits Idle state of Odd Even 5 to 8 Data Bits 1 unused next stabit 1 T ly Y T pxespe USER ed 1 I 1 1 ISTI cot Uo ipsc NUN 0 l E 171 15 4 2 Figure 1 Asynchronous Communications Bit Diagram This special bit is called the parity bit Parity is a simple method of determining if a data bit has been lost or corrupted during transmission There are several methods for implementing a parity check to guard against data corruption Comm
12. ates From the Port Settings Page you can enter a baud rate of any value from 1 to 230400 While it may not be possible to hit the exact desired baud rate the UART will attempt to set it as closely as possible and will be within an acceptable 246 range After you click Submit the page will refresh and display the baud rate actually being used Resetting to Factory Defaults If you have forgotten your password or otherwise wish to reset the device to the factory defaults manually browse to http x x x x debug htm where x x x x is the device s IP address and click the button marked Reset to Factory Defaults You will be prompted for a username and password For the username enter debug In the password field type the MAC address of the unit located either on the summary page or on the label on the device The MAC address should be entered without formatting such as dashes or spaces Sealevel Systems SeaLink 8 Ultra Page 4 Software Installation Windows Device Driver Configuration SeaLINK is a general purpose redirector client from Sealevel Systems Inc that lets Windows based PC applications use shared serial lines on serial servers SeaLINK supports up to 16 redirected COM ports With SeaLINK you can configure Windows applications to communicate with COM ports on a remote serial server as if they were local to the PC Users with a basic understanding of Windows can follow the steps below to be up and running in minutes M
13. cal Support 1 Verify that the Power LED is lit and remains on 2 Verify that the Link LED remains on to determine that the 10 100 Base T connections and the polarity are correct If the Link LED is lit you have a valid Link condition 3 Verify that the Ethernet LED remains on to determine that the 10 100 Base T connections and the polarity are correct If the Ethernet LED is lit you have a working Ethernet connection 4 Verify that the correct cable is being used i e Straight thru for switch hub connection and cross over for direct connection to NIC and that all cables are connected securely 5 Verify that the Ethernet Hub Switch and any other network devices between the server and the SeaLINK device is powered up and operating 6 Ensure that the Serial Server and Client are in the same sub net Broadcast Domain and not behind a router or bridge 7 Ensure that the IP address in the Client is the same as the IP address of the Server If using DHCP this address is subject to change after a Server reboot 8 To isolate the unit from the network use a crossover Ethernet cable to connect the unit directly to the NIC card in the server 9 Rebootthe server 10 Ensure that server software is correctly loaded 11 Remove and reload the server software 12 Update the firmware at ftp ftp sealevel com pub SOFTW ARE SEALINK Firmware CURRENT This link will provide the file and directions for updating your firmware
14. cations The output of the RS 422 485 driver is capable of being Active enabled or Tri State disabled This capability allows multiple ports to be connected in a multi drop bus and selectively polled RS 485 allows cable lengths up to 4000 feet and data rates up to 10 Megabits per second The signal levels for RS 485 are the same as those defined by RS 422 RS 485 has electrical characteristics that allow for 32 drivers and 32 receivers to be connected to one line This interface is ideal for multi drop or network environments RS 485 tri state driver not dual state will allow the electrical presence of the driver to be removed from the line Only one driver may be active at a time and the other driver s must be tri stated RS 485 can be cabled in two ways two wire and four wire mode Two wire mode does not allow for full duplex communication and requires that data be transferred in only one direction at a time For half duplex operation the two transmit pins should be connected to the two receive pins Tx to Rx and Tx to Rx Four wire mode allows full duplex data transfers RS 485 does not define a connector pin out or a set of modem control signals RS 485 does not define a physical connector Sealevel Systems SeaLink 8 Ultra Page 11 Appendix D Asynchronous Communications Appendix D Asynchronous Communications Serial data communications implies that individual bits of a character are transmitted consecutively to a receiver th
15. eeesss 12 APPENDIX E BACK PANEL ieee eo oo inen eo ea eoe so obs ee eo ae no ob ae ea vena ooo eno ee soccorso LO APPENDIX COMPLIANCE NOTICES 222 2 14 FEDERAL COMMUNICATIONS COMMISSION STATEMENT ccccccececececscececececececececececececeeeceeeceeeeeeecs 14 EMC DIRECTIVE STATEMENT 22 ceret tee eo eo aee dv aeo eos bee eub ds ae 14 Revision May 26 2004 Sealevel Systems Incorporated rights reserved Introduction Introduction Overview The Sealevel SEALINK 8 ULTRA Part number 4803 is an eight channel RS 232 422 485 Ethernet based serial I O adapter supporting data rates up to 230 4 K bps The RS 232 compatibility allows for connection to devices utilizing the RS 232 electrical interface such as modems data entry terminals and plotters RS 422 provides excellent communications for long distance device connections up to 4000ft where noise immunity and high data integrity are essential RS 485 is optimized for Multi Drop or Party line operations selecting data from multiple peripherals as many as 3 devices can be connected on an RS 485 bus What s Included The SEALINK 8 ULTRA is shipped with the following items If any of these items is missing or damaged contact the supplier SEALINK 8 ULTRA Ethernet Terminal Adapter Sealevel So
16. ftware 5 volt power adapter Sealevel Systems part number TR101 Ethernet cable straight through blue Ethernet cable cross over yellow Sealevel Systems SeaLink 8 Ultra Page 1 Card Setup Card Setup Electrical Interface Selection Each port on the SEALINK 8 ULTRA has the ability to be used in RS 422 485 This is selectable using the software setup utility and correctly configuring DIP switches S1 S4 RS 232 RS 422 485 RS 422 485 No termination RS 485 Enable Modes RS 485 is ideal for multi drop or network environments RS 485 requires a tri state driver that will allow the electrical presence of the driver to be removed from the line The driver is in a tri state or high impedance condition when this occurs One of the unique features of the SEALINK 8 ULTRA is the ability to be RS 485 compatible without the need for special software or drivers This ability means that the user can effectively use the SEALINK 8 ULTRA in an RS 485 application with the standard Sealevel Software supplied drivers Typically each end of the RS 485 bus must have a line terminating resistor RS 422 terminates the receive end only A 120 ohm resistor silk screen is across each RS 422 485 input in addition to a 1K ohm pull up silk screen and a 1K ohm pull down silk screen PD combination that biases the receiver inputs Only the ends of an RS 485 network should have the 120 Ohm terminating resistor The presence of the 1
17. list probably 1 1 to install it If your device is not listed type n and follow the prompts to tell the software about your device e When finished configuring ports type q to quit The SeaLINK driver must be restarted or started for the first time so type either sbin sealink restart or sbin sealink start If one gives you an error try the other one 2 Usage Details Once a device has been installed it can be accessed through the character devices dev ttySL 0 n where is the number of ports on your device minus one For example echo hello gt dev ttySLO will send the ASCII characters hello to the first serial port on your device while echo hello gt dev ttySL2 will do the same for the third serial port dev ttySL devices are designed to communicate with a virtualized a serial port so programs can access them just like a dev ttyS port using the termios functions see the man page for termios Note that unlike a normal serial port SeaLINK serial ports can only be opened by one program at a time This is done to ensure that the correct client receives the correct data signals Raw Data Sockets Raw Data Sockets are probably the easiest way for a software developer to control a serial port but provide the least control from a software standpoint You can simply open a socket to the device on the Raw Data TCP port corresponding to the serial port you want and stream data back and
18. ne the IP address The method depends on your operating system so see the appropriate section below Device Configuration with Windows Windows device configuration is performed through the SeaLINKConfig exe Start Programs SeaLINK utility provided with the software installation When started the utility will display all devices on the local network the utility cannot see devices on the other side of a router If your device is not listed verify that it is connected to the network see the section Troubleshooting To assign static IP addresses select your device in the list then uncheck the box that says Enable DHCP and change the IP Gateway and Network Mask fields to values valid on your network Then click Apply Changes The device will reboot and temporarily disappear from view so you may need to click Search Again to relocate the device Sealevel Systems SeaLink 8 Ultra Page 3 Software Installation Device Configuration with Linux Linux device configuration is performed through the SeaLINKConfig console utility provided with the software installation Once the software has been installed correctly type usr sbin sealinkcfg to launch the program You should see a list of all devices on the local network the utility cannot see devices on the other side of a router If your device is not listed verify that it is connected to the network see the section Troubleshooting To as
19. on methods are called E ven Parity or O dd Parity Sometimes parity is not used to detect errors on the data stream This is refereed to as N o parity Because each bit in asynchronous communications is sent consecutively it is easy to generalize asynchronous communications by stating that each character is wrapped framed by pre defined bits to mark the beginning and end of the serial transmission of the character The data rate and communication parameters for asynchronous communications have to be the same at both the transmitting and receiving ends The communication parameters are baud rate parity number of data bits per character and stop bits i e 9600 8 1 Sealevel Systems SeaLink 8 Ultra Page 12 Appendix E Back Panel Appendix E Back Panel PDRT l E 5 DONEC ERU Quai leap 477 e PORT 4 Sealevel Systems SeaLink 8 Ultra Page 13 Appendix Compliance Notices Appendix F Compliance Notices Federal Communications Commission Statement FCC This equipment has been tested and found to comply with the limits for Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with
20. ore information is available in the full User s Guide and on the Sealevel Systems Inc website 1 Confirm the following You are using an Intel compatible PC running Windows 2000 Windows NT 4 0 SP5 Windows ME Windows 98 or Windows XP Install SeaLINK on your PC Log in as a user with administration privileges It is not necessary to be an admin to use SeaLINK Quit all Windows programs that use COM ports Run the SeaLINKConfig program and note your IP address SeaLINKConfig will find all of the SeaLINK servers currently installed on the same network segment Broadcast Domain as the machine you are executing it from Create the SeaLINK COM ports After the installer runs the Select Ports Window appears Check one or more new COM ports for SeaLINK to create and click OK Note The list of COM ports will not include those already in use by Windows on this PC Configure and verify SeaLINK COM ports Do not enter any values in the User Name or Password field These fields are not valid for this version of SeaLINK The main SeaLINK Window should now be open If not right click on the SeaLINK icon in the System Tray and choose Configure Then enter the serial server s IP Address and Port Number in the boxes provided for each COM port Note The SeaLINK Serial Server will place the port at 4680 Click the Configuration Wizard button in the Main Window and then click Start This important step will confirm that each new port just
21. se Authorization RMA Number Sealevel Systems SeaLink 8 Ultra Page 10 Appendix Electrical Interface Appendix C Electrical Interface RS 232 Quite possibly the most widely used communication standard is RS 232 This implementation has been defined and revised several times and is often referred to as RS 232 C D E or EIA TIA 232 C D E It is defined as Interface between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange mechanical implementation of RS 232 is on 25 pin D sub connector The PC computer defined the RS 232 port on a 9 pin D sub connector and subsequently the EIA TIA approved this implementation as the EIA TIA 574 standard This standard has defined as the 9 Position Non Synchronous Interface between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange Both implementations are in wide spread use and will be referred to as RS 232 in this document RS 232 is capable of operating at data rates up to 20K bps 50 ft The absolute maximum data rate may vary due to line conditions and cable lengths RS 232 often operates at 38 4K bps over very short distances The voltage levels defined by RS 232 range from 12 to 12 volts RS 232 is a single ended or unbalanced interface meaning that a single electrical signal is compared to a common signal ground to determine binary logic states A voltage of 12 volts us
22. sign a static IP address type for configure followed by the number of your hub in the displayed list probably 1 Hit return and answer n when asked if the device should use DHCP Then enter Gateway and Network Mask settings valid on your network The device will reboot and temporarily disappear from view so you may need to type r to refresh the device list Web Configuration Once the device has been assigned an IP address reachable from your computer you can configure it through the onboard web server Open a web browser such as Internet Explorer or Netscape and type http x x x x into the URL field where is device s IP address The web interface provides a summary page that lists various details about the device a port settings page that allows you to configure aspects of each serial port and an administration page that lets you change the device s network and password settings Port Defaults The Port Settings page allows you to set defaults for the serial port If you are using a virtual serial port protocol such as SeaLINK Software programs may change these settings dynamically after opening the ports If you want programs to always use the defaults you set check the box labeled Always use defaults This can be useful especially when specifying a custom baud rate that is not available from your operating system see Custom Baud Rates Custom Baud R
23. the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in such case the user will be required to correct the interference at the users expense EMC Directive Statement C Products bearing the CE Label fulfill the requirements of the EMC directive 89 336 EEC and of the low voltage directive 73 23 EEC issued by the European Commission To obey these directives the following European standards must be met EN55022 Class A Limits and methods of measurement of radio interference characteristics of information technology equipment EN55024 Information technology equipment Immunity characteristics Limits and methods of measurement EN60950 IEC950 Safety of information technology equipment including electrical business equipment Warning This is a Class A Product In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures to prevent or correct the interference Always use cabling provided with this product if possible If no cable is provided or if an alternate cable is required use high quality shielded cabling to maintain compliance with FCC EMC directives Sealevel Systems SeaLink 8 Ultra Page 14 Warranty Warranty Sealevel s commitment to providing the best I O solutions is reflected in the Lifetime Warr
24. ually 3 to 10 volts represents a binary 0 space and 12 volts 3 to 10 volts denote a binary 1 mark The RS 232 and the EIA TIA 574 specification define two types of interface circuits Data Terminal Equipment DTE and Data Circuit Terminating Equipment DCE The Sealevel Systems Adapter is a DTE interface RS 422 The RS 422 specification defines the electrical characteristics of balanced voltage digital interface circuits RS 422 is a differential interface that defines voltage levels and driver receiver electrical specifications On a differential interface logic levels are defined by the difference in voltage between a pair of outputs or inputs In contrast a single ended interface for example RS 232 defines the logic levels as the difference in voltage between a single signal and a common ground connection Differential interfaces are typically more immune to noise or voltage spikes that may occur on the communication lines Differential interfaces also have greater drive capabilities that allow for longer cable lengths RS 422 is rated up to 10 Megabits per second and can have cabling 4000 feet long RS 422 also defines driver and receiver electrical characteristics that will allow 1 driver and up to 32 receivers on the line at once RS 422 signal levels range from 0 to 5 volts RS 422 does not define a physical connector RS 485 RS 485 is backwardly compatible with RS 422 however it is optimized for party line or multi drop appli
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