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National Instruments 321827C-01 User's Manual

1. Figure 2 6 DB 9 Connector Pin Locations Table 2 1 DB 9 Pin Descriptions DB 9 Pin 232 Signal 485 Signal 1 DCD GND 2 RXD CTS HSI 3 TXD RTS HSO 4 DTR RXD 5 GND RXD 6 DSR CTS HSI 7 RTS RTS HSO 8 CTS TXD 9 RI TXD These signals are not supported by the isolated 232 boards or ports 9 16 of the RS 232 sixteen port board PCMCIA Serial for Windows Me 9x 2 8 ni com Chapter 2 Installation and Verification Connecting Two Wire Devices The PCMCIA 485 boards are designed to work with either two or four wire devices If you are using a two wire device refer to the device documentation for specific wiring instructions In general half duplex networks use a single twisted pair of wires for communication in both directions so you must connect both the transmitter and the receiver at each end of the same pair of wires For example to connect an RS 485 data acquisition device to a port on your PCMCIA 485 using half duplex communication you need a single twisted pair of wires At the PCMCIA 485 connect the TXD and RXD signals pins 8 and 4 on a DB 9 connector together and to one wire Connect the other end of this wire to both the TXD and RXD signals on the data acquisition device You use the same method to connect the TXD and RXD signals pins 9 and 5 on a DB 9 connector to the second wire For information about setting the transceiver mode f
2. Electrical Characteristics of Balanced Voltage Digital Interface Circuits EIA 485 Standard Standard for Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multipoint Systems Microsoft Win32 Software Developer Kit Online Documentation for Win32 Overviews Win32 Reference and Microsoft Programmer s Guide to Windows 98 95 Microsoft Corporation NSI6550AF Universal Asynchronous Receiver Transmitter with FIFOs National Semiconductor ST16C654 Asynchronous Receiver Transmitter with FIFOs EXAR Corporation xii ni com Introduction This chapter explains how to use this manual lists what you need to get started and optional equipment you can order and briefly describes the serial hardware and the NI Serial software How to Use This Manual Chapter 1 a Gather What You Need P to Get Started v Install the NI Serial Software Install the Serial Hardware Chapter 2 Verify the Installation i No __ Troubleshooting Yes y Connect the Cables y Chapter 3 Configure the Serial Port y Learn About Transceiver Control Modes Chapter 4 y Review Programming Requirements y Write Application Program National Instruments Corporation 1 1 PCMCIA Serial for Windows Me 9x Chapter 1 Introduction What You Need to Get Started Before you install your serial hardware and the NI Serial software make sure you h
3. 1 4 Using Your Serial Hardware with LabVIEW and LabWindows CVL eee 1 4 Chapter 2 Installation and Verification Install the SoftWare siiis aiana eaa EE ceased vente A ATA 2 1 Install the HardWare nn ees a an A A E E E S S 2 3 Verify the Installation iani e E A E EE NES 2 4 Verify the Hardware ReEsources eeeeseeseeesseerssesesrestererrestrsesresresesresesresresrst 2 6 Determine Which Physical Port Is Associated with COMX 2 7 Run the Diagnostic Testerenin enn a Ea a deeds staestevics eget etees 2 7 Connect the Cables a asian tela te tee a Nek Satay 2 8 Connecting Two Wire Devices c tescesecs yececechstescecvevsueescuangessonscostestessesenerseovesevennessves 2 9 Chapter 3 Configuration View or Change Communication Port Settings 0 0 eee ee ceesseesecesecseeeseeeeeneeeaeenaes 3 1 Port Settings Tabi en cits at deh eee el rn alee ete Paterna oan ate geek teed 3 2 Bits Per Second i 43 Sab ed eesti ie Ae teh eae Cee E E EEA 3 3 Data Bits venente aar a aa a S peed evtverhs Serre einen 3 3 Arty e eat NAG a A eee eas 3 3 SLOP Bitsin iieis iE E E ectsscuvsd epduivenn E E E Seve ae ee 3 3 Blow Control 2 inch scien A eds E E N 3 3 National Instruments Corporation vii PCMCIA Serial for Windows Me 9x Contents Advanced Port Settings 0 0 eee eceeeeseeseceeeeseceeeesesseeeseeseeesecseeeaesnessaeseenaes 3 3 Trahsceivet MOG ca ssescetsscdsessgecssceassacdesesdeessesse sabes scevecasci an 3 4 Use FIFO Butlers ens
4. Click on the Remove button aye Note To remove ports on two port and four port PCMCIA cards from within the Device Manager you must open the Multi function adapters class select the name of your interface and click on the Remove button 7 Inthe Confirm Device Removal dialog box click on the OK button to remove this interface or click on Cancel to cancel your request PCMCIA Serial for Windows Me 9x B 2 ni com Uninstall the Software Appendix B Uninstalling the Hardware and Software Before uninstalling the software remove all serial port information from the Windows Me 9x Device Manager as described in the previous section You do not need to shut down Windows Me 9x before uninstalling the software Complete the following steps to remove the NI Serial software 1 2 National Instruments Corporation Select Start Settings Control Panel Double click on the Add Remove Programs icon in the Control Panel to launch the Add Remove Programs applet A dialog box similar to the one in Figure B 2 appears This dialog box lists the software available for removal Add Remove Programs Properties 29 x Install Uninstall Windows Setup Startup Disk To install a new program from a floppy disk or CD ROM drive click Install 722 The following software can be automatically removed by v Windows To remove a program or to modify its installed components select it from the list and click Add Remove Microsoft
5. D 1 Physical Characteristics of the PCMCIA Serial Cards Characteristic Specification Dimensions 85 6 by 54 0 by 0 5 cm 3 370 by 2 126 by 0 197 in I O Connector Special Cable with DB 9 Dsub Connector and Converter for PC Card Power Requirement from PCMCIA expansion slot PCMCIA 232 PCMCIA 485 PCMCIA 232 2 PCMCIA 485 2 PCMCIA 232 4 5 VDC 5 VDC 5 VDC 5 VDC 5 VDC 40 mA Typical 100 mA Typical 60 mA Typical 100 mA Typical 60 mA Typical National Instruments Corporation D 1 PCMCIA Serial for Windows Me 9x Appendix D Specifications Table D 2 Environmental Characteristics of the Serial Hardware Characteristic Specification Operating Environment Component Temperature 0 to 70 C Relative Humidity 10 to 90 noncondensing Storage Environment Temperature 40 to 120 C Relative Humidity 5 to 90 noncondensing EMI FCC Class A Verified Software Specifications Table D 3 Software Characteristics Characteristic Specification Maximum Serial Transfer Rate 115 200 bps Actual speed may vary considerably from speed shown due to system and instrumentation capabilities PCMCIA Serial for Windows Me 9x D 2 ni com Technical Support Resources Web Support National Instruments Web support is your first stop for help in solving installation configuration and application problems and questi
6. PCMCIA Serial for Windows Me 9x 1 2 ni com Chapter 1 Introduction The PCMCIA 485 interfaces support four hardware transceiver control modes for reliable communication with two wire and four wire devices Refer to Chapter 4 Using Your Serial Hardware for more information about transceiver control modes All of the serial hardware uses standard 16550 compatible UARTs Universal Asynchronous Receiver Transmitters for 100 percent compatibility with standard PC COM ports The serial hardware contains FIFOs First In First Out buffers for reduced susceptibility to interrupt latency and faster transmission rates Full Plug and Play compatibility gives you the convenience of switchless configuration and installation Refer to Appendix D Specifications for more information about the serial hardware specifications and operating conditions Nl Serial Software Overview The NI Serial software for Windows Me 9x includes a native Windows device driver that provides full interrupt driven buffered I O for multiple COM ports You can obtain a maximum baud rate of 115 2 KBaud You can also use any number of serial ports under Windows Me 9x The NI Serial software also includes a configuration utility which is fully integrated into the Windows Me 9x Device Manager For more information about software specifications refer to Appendix D Specifications The NI Serial software includes the following components e Device driver e Diagnostic utili
7. View devices by type button 3 Double click on the Ports COM amp LPT icon to display a list of installed ports How can I determine which version of the NI Serial software I have installed The Read Me file gives the version of the software To open the file select Start Programs National Instruments Serial Read Me What do I do if the diagnostic test fails with an error Refer to the Troubleshooting Diagnostic Messages section earlier in this appendix How can I determine which port is associated with COMx Refer to the section Determine Which Physical Port Is Associated with COMsx in Chapter 2 Installation and Verification How can I change the COM number of my National Instruments serial ports Table C 1 lists standard DOS base addresses for serial ports Table C 1 Standard DOS Based Addresses COM Port Base Address COM1 3f8 COM2 28 COM3 3e8 COM4 2e8 National Instruments Corporation C 5 PCMCIA Serial for Windows Me 9x Appendix C Troubleshooting and Common Questions In most cases Windows Me 9x does not assign names COM 1 through COM4 to the serial hardware Rather it names the ports starting with COMS If you assign any of the base addresses in Table D 1 to a National Instruments serial port Windows Me 9x automatically changes the COM port name to the corresponding one listed in this table You do not need to change the IRQ setting for this name change to occur To cha
8. YAMAHA OPL3 SAx GamePort SAk AIA OMAA O mand Marakana Properties Refresh Remove Print e 4 1 1G Figure 2 5 Device Manager Ports List for PCMCIA Serial Card Incorrectly Installed Verify the Hardware Resources For every port of the newly installed serial interface double click on the name of the serial port in the Device Manager Then click on the Resources tab If the resources were assigned correctly the Resources page shows which resources are assigned to your serial ports If Windows Me 9x did not assign any resources to the port the Resources page shows only a Set Configuration Manually button Click on the Set Configuration Manually button and try to assign conflict free resources to your serial hardware For instructions refer to the Selecting Conflict Free Resources section of Appendix C Troubleshooting and Common Questions You might have to free an interrupt request level so that one can be assigned to your serial hardware For instructions refer to the section Freeing an Interrupt Request Level in Appendix C Troubleshooting and Common Questions When you have finished verifying the hardware resources proceed to the next section PCMCIA Serial for Windows Me 9x 2 6 ni com Chapter 2 Installation and Verification Determine Which Physical Port Is Associated with COMx For every port of the newly installed serial interface
9. for Windows Me 9x Appendix A Serial Port Information Pin 2 Pin 3 aP Pno Pin 2l PP pind TxD o DCE DCE xp _ l DTE _1X Pin Pin 3 2 a Pin 3 Figure A 4 Straight Through Cabling in a DTE to DCE Interface Straight through cabling is still the standard method to connect a modem to your PC However because many applications use serial communication to connect two or more DTEs without modems the cabling becomes more complicated If two DTEs are wired together using a straight through cable one transmitter is connected to the other transmitter and one receiver is connected to the other receiver In this setup no transmissions can occur Thus these applications must use a cabling scheme that connects the transmitter on one device to the receiver on the other device and vice versa This method is known as null modem cabling because it replaces the two modems that traditional RS 232 applications would require between the two DTEs To communicate from one serial port to another use a null modem cable Figure A 5 shows null modem cabling in a DTE to DTE interface Rx D Rx D _ Pin 2 Pin 2 DTE x DTE TxD TxD Pin 3 Figure A 5 Null Modem Cabling in a DTE to DTE Interface PCMCIA Serial for Windows Me 9x A 6 ni com Uninstalling the Hardware and Software This appendix describes how to uninstall your serial hardware and the NI Serial software Unins
10. or COM 8 Figure C 1 shows the Ports list in the Device Manager with a port selected System Properties 21x General Device Manager Hardware Profiles Performance View devices by type View devices by connection E Keyboard Modem Monitor 4 2 Mouse S gt Multi function adapters gt N I PEM 4 Multi function Parent Network adapters 9 Other devices H PCMCIA socket Y Ports COM amp LPT Communications Port COM1 F N I POMC14 232 4 Communications Port COMS N I PCMCIA 232 4 Communications Port COME F N I PCMCIA 232 4 Communications Port COM N I POMCIA 232 4 Communications Port COM8 a Printer Port LPT2 POTN r ee a re ee ey eee operties Refresh Remove Print Figure C 1 Ports List in Device Manager Tab 7 Click on the Remove button and click on OK to confirm the removal of the serial hardware information 8 Repeat steps 6 and 7 until all serial port entries are removed Then click on Refresh to force Windows Me 9x to detect serial hardware and display the New Hardware Found dialog box PCMCIA Serial for Windows Me 9x C 4 ni com Appendix C Troubleshooting and Common Questions Common Questions How can I determine which type of serial hardware I have installed 1 Select Start Settings Control Panel and double click on the System icon 2 Click on the Device Manager tab and click on the
11. Installed ic ies ccscsscesetseccecssettacel sg covasdesesscounzetvaaseedevecaacsestepesaches 2 5 Figure 2 5 Device Manager Ports List for PCMCIA Serial Card Incorrectly Installed nennen nann enn in 2 6 Figure 2 6 DB 9 Connector Pin Locations 2000 0 eee ees eeeeseeeeeeseeseeeseeeeeseeaeeeaes 2 8 Figure 3 1 Port Settings Tab oe ceceseeseeeseceeeesesseesseesesesecsesnsesseseseeaeenaes 3 2 Figure 3 2 Advanced Port Settings Dialog BOX ec eeeeseeseeseeeeeneeneeeeenaes 3 3 Figure A 1 Typical Full Duplex System o oo eseeeeneceeeeeensecseseeeeseeeees A 4 Figure A 2 Typical Half Duplex System eee eseesecneceeeeseenseeeenseeneenaes A 4 Figure A 3 Multidrop Network Using Terminating Resistors ee eects A 5 Figure A 4 Straight Through Cabling in a DTE to DCE Interface A 6 Figure A 5 Null Modem Cabling in a DTE to DTE Interface oo A 6 Figure B 1 Selecting an Interface to Uninstall ssessesesssessseseersrreresreresreresresrsses B 2 Figure B 2 Add Remove Programs Properties Dialog BOX eee eee eeeeeees B 3 Figure B 3 Successful Uninstallation occ eee eeceeseceecseceseceeeaeseeeeseeneeeeenaes B 4 Figure C 1 Ports List in Device Manager Tab eee ceeeeeecseeeseenseeseeeenaes C 4 Figure C 2 Multi Function Adapter Class in the Device Manager eee C 7 Tables Table 2 1 DB 9 Pin Descriptions eee stasiun aniier sos 2 8 Table 4 1 Transceiver Control Modes 0 ccccccccessssssceceeessseeececesssseeeeeessee
12. Publisher 97 Microsoft Small Business Financial Manager 97 Microsoft Visual C 5 0 Microsoft Word 97 National Instruments Serial NI CAN v1 2 1 NI CCDB for Windows 95 NT NI VISA for Windows 95 NT NuMega SoftICE xl Add Remove OK Cancel Apply Figure B 2 Add Remove Programs Properties Dialog Box B 3 PCMCIA Serial for Windows Me 9x Appendix B Uninstalling the Hardware and Software 3 Select the serial software you want to remove and click on the Add Remove button The uninstall program runs and removes all folders programs VxDs DLLs and registry entries associated with the NI Serial software Figure B 3 shows the results of a successful uninstallation 4 Remove your PCMCIA card from your computer Remove Programs From Your Computer Figure B 3 Successful Uninstallation If you want to reinstall the hardware and software refer to Chapter 2 Installation and Verification PCMCIA Serial for Windows Me 9x B 4 ni com Troubleshooting and Common Questions This appendix describes how to troubleshoot problems and answers some common questions Freeing an Interrupt Request Level To free an interrupt request level for your serial port you must disable the device that is using the interrupt request level To view the system wide allocation of interrupt request resources and remove a device complete the following steps 1 Select Start Settings Control Panel and double cli
13. Serial Getting Started with Your PCMCIA Serial Hardware and Software for Windows Me 9x Wy NATIONAL i September 2000 Edition gt INSTRUMENTS Part Number 321827C 01 Worldwide Technical Support and Product Information ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 794 0100 Worldwide Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 China 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico D F 5 280 7625 Mexico Monterrey 8 357 7695 Netherlands 0348 433466 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 0 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 For further support information see the Technical Support Resources appendix To comment on the documentation send e mail to techpubs ni com Copyright 1998 2000 National Instruments Corporation All rights reserved Important Information Warranty The serial hardware is warranted against defects in materials and workmanship for a p
14. TROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Compliance FCC Canada Radio Frequency Interference Compliance Determining FCC Class The Federal Communications Commission FCC has rules to protect wirel
15. ained multiple instruments together you need a terminating resistor at only the first and last instruments The terminating resistor should match the characteristic impedance of the transmission line typically 100 to 120 Q You can order an optional DB 9 RS 485 termination connector that contains embedded terminating resistors for easy termination from National Instruments For ordering information contact National Instruments Figure A 3 shows a multidrop network using terminating resistors Slave 1 Slave 2 Slave n JN AN AN z 1002 Y Foa MASTER oH Figure A 3 Multidrop Network Using Terminating Resistors DTE vs DCE In the RS 232 specification DTE Data Terminal Equipment and DCE Data Communications Equipment refer to the types of equipment on either end of a serial connection In general DTE and DCE refer to computer equipment and modems respectively Because the RS 232 specification mainly involves connecting a DTE directly to a DCE and vice versa the pinouts are defined so that cabling is simple That is a cable connected a computer to a modem by wiring pin to pin 1 pin 2 to pin 2 and so on This method is known as straight through cabling Figure A 4 shows straight through cabling in a DTE to DCE interface 1 In Revision D of the RS 232 specification a DCE is a Data Circuit Terminating Equipment National Instruments Corporation A 5 PCMCIA Serial
16. al system The two common means of bi directional serial communication are full duplex and half duplex Half duplex communication involves a transmitter and a receiver connected to each end of the same wire or pair of wires Because the same transmission line both sends and receives data devices cannot send data in both directions at the same time First one device transmits over the wire s to the receiver of the second device When the first device finishes transmitting both devices switch the connections from their transmitter to their receiver or vice versa The device that was receiving data can then transmit over the line In full duplex communication the devices use a separate wire or pair of wires for simultaneous transmission in each direction Thus the devices do not switch between transmitting and receiving In a differential serial bus such as RS 422 or RS 485 a half duplex system transmits and receives over the same twisted pair of wires Thus half duplex communication is often referred to as two wire communications Likewise full duplex communication is often referred to as four wire communications because the full duplex system uses a separate pair of wires for communication in each direction Full Duplex A typical full duplex multidrop bus architecture involves a master slave protocol Only one device the master can control access to the bus All other devices are slaves Slave devices must wait for the master to g
17. ardware or niserial vxd file is missing reinstall the hardware and software You can find niserial vxd in the Windows systenm directory C 2 ni com Appendix C Troubleshooting and Common Questions If the utility reports fewer ports installed than it should refer to Chapter 2 Installation and Verification and follow these troubleshooting steps 1 Verify the hardware resources 2 In some versions of Windows Me 9x the Driver tab in the Device Manager gives you the information about the driver installed Verify that the National Instruments serial driver is installed for the port 3 Check the hardware installation to make sure the correct number of boards ports are installed Ifthe I O address test failed Interrupt test cannot be performed error message appears verify the hardware resources as described in Chapter 2 Installation and Verification If the test still fails you probably have an I O address conflict with legacy boards Refer to the next section Resolving Resource Conflicts with Legacy Boards Ifthe Interrupt test failed error message appears verify the hardware resources as described in Chapter 2 Installation and Verification If the test still fails you probably have an interrupt level conflict with legacy boards Refer to the next section Resolving Resource Conflicts with Legacy Boards Resolving Resource Conflicts with Legacy Boards Resource conflicts typically occur if your system contains legacy
18. ave all of the following items Q Windows Me 9x installed on your computer Q One of the following serial interfaces which is included in your kit PCMCIA 232 one two or four port PCMCIA 485 one or two port Q CD N Serial Software for Windows 2000 NT Me 9x which is included in your kit Q Adapter cable from PCMCIA card to DB 9 connector which is included in your kit Optional Equipment For more information about ordering the following optional equipment contact National Instruments e DB 9 RS 485 termination connector e RS 232 9 pin to 9 pin null modem cable e RS 232 9 pin to 25 pin null modem cable e RS 485 9 pin to 9 pin null modem cable Serial Hardware Overview The serial hardware gives you a variety of solutions for serial communications The PCMCIA 232 interfaces work with the RS 232 protocols and the PCMCIA 485 interfaces work with the RS 422 and RS 485 protocols You can use the PCMCIA 232 hardware for serial communication up to distances of 50 ft You can connect the PCMCIA 485 hardware with up to 31 devices using serial cable lengths up to 4 000 ft The PCMCIA 232 is available with one two or four ports The PCMCIA 485 is available in a one port version or two port version All PCMCIA cards come with cables for each port that terminates in a standard DB 9 D Sub connector Throughout this manual references to PCMCIA serial interfaces generally refer to all versions of the interfaces
19. bits in each transmitted byte Stop Bits Stop bits is the number of terminating bits on the end of each transmitted serial byte Flow Control Flow control is a method for temporarily halting the stream of serial bytes to prevent overflow Advanced Port Settings You can view or change the advanced port settings by clicking on the Advanced button on the Port Settings tab Figure 3 2 shows the Advanced Port Settings dialog box National Instruments Corporation Advanced Port Settings x Transceiver Mode 4 wire 4 wire 2 wire DTR echo Z wire DTR ctl J7 Use FIFO buffers SE ert Select lower settings to corect connection problems Select higher settings for faster performance Receive Buffer Low 1 _ High 14 Transmit Buffer Low 1 J High 16 Cancel Defaults Figure 3 2 Advanced Port Settings Dialog Box 3 3 PCMCIA Serial for Windows Me 9x Chapter 3 3 Restore Defaults Configuration The following sections describe the advanced settings options Transceiver Mode This field shows the transceiver mode in use and applies only to PCMCIA 485 boards For more information about transceiver modes refer to Chapter 4 Using Your Serial Hardware Use FIFO Buffers FIFO buffers are present on the 16550 compatible UARTs one for the transmitter and one for the receiver The Receive Buffer control sets the number of characters received in the FIFO before the PC is
20. boards that use resources that are not reserved properly If a resource conflict exists write down the resource that caused the conflict and refer to the Microsoft Windows Me 9x user s guide for instructions on how to use the Device Manager to reserve I O and IRQ resources for legacy boards Forcing Windows to Detect Your Hardware If Windows does not detect your serial hardware correctly or you have been using your serial hardware with the default Windows serial driver or an older version of the NI Serial software Windows does not display the New Hardware Found dialog box To fix this problem follow these steps l 2 3 National Instruments Corporation Select Start Settings Control Panel Double click on the System icon Select the Device Manager tab C 3 PCMCIA Serial for Windows Me 9x Appendix C Troubleshooting and Common Questions 4 Click on the View devices by type button 5 Double click on the Ports COM amp LPT icon to display a list of all ports that Windows recognizes If you have previously installed a PCMCIA serial card double click on Other Devices where Windows lists the ports it does not recognize 3 Note To remove ports on two or four port cards you must open the Multifunction adapter class select the name of the interface and click on the Remove button 6 Select a National Instruments port name from the list of ports that corresponds to a serial port for example COM 5 COM 6 COM 7
21. ccident actions of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks CVI LabVIEW National Instruments and ni com are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CON
22. ce manager tab for PCMCIA serial card ports incorrectly installed figure 2 6 device manager tab ports list figure 2 5 C 4 DeviceloControl 4 4 input values table 4 4 setting transceiver mode with 4 4 diagnostic messages C 2 troubleshooting C 2 diagnostic test failure C 5 PCMCIA Serial for Windows Me 9x Index DOS based addresses table C 5 DTE vs DCE A 5 DTE to DCE interface A 6 straight through cabling in figure A 6 DTE to DTE interface A 6 null modem cabling in figure A 6 duplex architectures A 3 full duplex A 3 half duplex A 4 E environmental characteristics D 2 F FIFO buffers 3 4 flow control 3 3 forcing Windows to detect hardware C 3 four wire mode 4 2 freeing an interrupt request level C 1 full duplex A 3 full duplex system figure A 4 G general programming requirements 4 1 getting started 1 2 glossary G 1 H half duplex A 4 half duplex system figure A 4 hardware installation 2 3 getting started 1 2 verification 2 4 hardware resources verification 2 6 PCMCIA Serial for Windows Me 9x installation determining port associated with COMx 2 7 getting started 1 2 running the diagnostic test 2 7 serial hardware 2 3 serial software 2 1 verification 2 1 verifying hardware installation 2 4 verifying hardware resources 2 6 interrupt request level C 1 freeing C 1 introduction 1 1 L LabVIEW 1 4 using with serial hardware 1 4 LabWind
23. ck on the System icon 2 Click on the Device Manager tab 3 Double click on the Computer icon and click on the View Resources tab 4 Click on the Interrupt Request IRQ button Scan through the list of IRQ settings to determine which devices are using which interrupt request levels 5 When you locate a device that you are not currently using click on the Cancel button 6 Inthe Device Manager tab double click on the icon for that device 7 Inthe Device usage field a checkmark appears to the left of the current configuration usually Original Configuration Current Click on the checkbox to remove the checkmark 8 Click on the Resources tab and make sure that Use automatic settings is unchecked 9 Repeat steps 7 through 9 for each unused device 10 Click on the OK button to save your changes 11 Restart Windows Me 9x to assign resources to your serial port Then complete step 6 in the Verify the Installation section of Chapter 2 Installation and Verification National Instruments Corporation C 1 PCMCIA Serial for Windows Me 9x Appendix C Troubleshooting and Common Questions Selecting Conflict Free Resources When the Device Manager indicates a conflict with another device you can usually correct the problem by manually selecting conflict free resources To do so complete the following steps 1 Select Start Settings Control Panel and double click on the System icon Click on the Device Manag
24. dition The reader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood a
25. double click on the name of the serial port in the Device Manager Then click on the Port Settings tab The top of this page displays the serial number of the serial hardware and the physical port number starting at 1 When you have finished verifying the driver installation and physical port proceed to the next section Run the Diagnostic Test To verify and test the installation run the diagnostic program that came with your NI Serial software The diagnostic program verifies that your serial driver is installed properly that the configuration of your hardware does not conflict with anything else in your system and that the serial driver can communicate with your hardware correctly To run the test select the diagnostics item under Start Programs National Instruments Serial If the diagnostic test completes with no failures your serial hardware and software are installed properly If it fails refer to Appendix C Troubleshooting and Common Questions for troubleshooting instructions National Instruments Corporation 2 7 PCMCIA Serial for Windows Me 9x Chapter 2 Installation and Verification Connect the Cables For the PCMCIA serial cards you can use the standard DB 9 connector found on most serial cables Figure 2 6 and Table 2 1 give the pin locations and descriptions of the DB 9 connector which is found on the PCMCIA serial cable PIN 5 PIN 1 j PIN 9 PIN 6 p
26. ds C 3 restoring defaults 3 4 RS 232 standard A 1 features table A 1 RS 422 standard A 2 features table A 1 RS 485 standard A 2 features table A 1 running the diagnostic test 2 7 S selecting an interface to uninstall figure B 2 selecting conflict free resources C 2 serial communication issues A 3 DTE vs DCE A 5 duplex architectures A 3 termination A 5 serial hardware forcing Windows to detect C 3 general programming requirements 4 1 installation 2 3 overview 1 2 selecting an interface to uninstall figure B 2 uninstalling B 1 using 4 1 using with LabVIEW and LabWindows CVI 1 4 serial port information A 1 serial software add remove programs properties dialog box figure B 3 installation 2 1 overview 1 3 PCMCIA Serial for Windows Me 9x Index successful uninstallation figure B 4 uninstalling B 3 setting transceiver control mode 4 3 setting with DeviceloControl 4 4 setup screen for NI Serial software figure 2 2 software installation 2 1 getting started 1 2 software specifications D 2 specifications D 1 environmental characteristics D 2 physical characteristics D 1 software specifications D 2 standard DOS based addresses table C 5 stop bits 3 3 straight through cabling in a DTE to DCE interface figure A 6 successful uninstallation figure B 4 system integration by National Instruments E 1 T technical support resources E 1 termination A 5 multid
27. e mat riel brouilleur du Canada Class B Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver e Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe B respecte toutes les exigences du R glement sur le mat riel brouilleur du Canada European Union Compliance to EEC Directi
28. e the input buffer values unsigned long listed in Table 4 3 for programming different transceiver modes Table 4 3 DeviceloControl Function Input Values Transceiver Mode DeviceloControl Function Input Value Four wire mode 128 Two wire mode DTR with echo 129 Two wire mode DTR controlled 130 Two wire mode TXRDY auto control 131 For example to set TXRDY two wire auto control mode use the following code ULONG TranceiverMode 131 DeviceloControl hDevice IOCTL SERIAL SET TRANSCEIVER MODE PVOID amp TransceiverMode sizeof ULONG lpOutBuffer nOutBufferSize lpBytesReturned lpOverlapped PCMCIA Serial for Windows Me 9x 4 4 ni com Serial Port Information RS 232 This appendix describes the RS 232 RS 422 and RS 485 standards and explains some of the issues involved with these types of serial communication Table A 1 lists the features of the RS 232 RS 422 and RS 485 standards Table A 1 RS 232 RS 422 and RS 485 Features Feature RS 232 RS 422 RS 485 Type of Single ended Differential Differential transmission lines Maximum number 1 1 32 of drivers Maximum number 1 10 32 of receivers Maximum cable 50 ft 4 000 ft 4 000 ft length Maximum data rate 20 kbytes s 10 Mbytes s 10 Mbytes s Maximum CMV 25 V 7 V 12 to 7 V Driver output 5to25 V 2to6 V 1 5 to 6 V Driver load gt 3 kQ 100 Q 60 Q Nati
29. eeeeesaes 4 2 Table 4 2 Transceiver Mode Control Bytes 0 eee ceeeseeseeseesseeeeeeeeeeeeeeeeees 4 3 Table 4 3 DeviceloControl Function Input Values 0 eee eseeseeereeneee 4 4 Table A 1 RS 232 RS 422 and RS 485 Features ccccsccccesssscecceeesseeeeeeeees A 1 Table C 1 Standard DOS Based Addresses ccccsccccessssscecceeesseeeeesessseeeeeeesnes C 5 Table D 1 Physical Characteristics of the PCMCIA Serial Cards 0 e D 1 Table D 2 Environmental Characteristics of the Serial Hardware 005 D 2 Table D 3 Software Characteristics cccccccsssccccessssscecceessssseecesessseeecceessseeeeeeseas D 2 National Instruments Corporation ix PCMCIA Serial for Windows Me 9x About This Manual Conventions This manual contains instructions to help you install and configure the National Instruments serial hardware and the NI Serial software for Windows Me 9x This manual includes information about the PCMCIA 232 PCMCIA 232 2 PCMCIA 232 4 PCMCIA 485 and PCMCIA 485 2 This manual assumes that you are already familiar with Windows Me 9x italic monospace monospace bold The following conventions appear in this manual The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon den
30. er mode 3 4 using FIFO buffers 3 4 advanced transceiver control for the PCMCIA 485 4 1 four wire mode 4 2 setting transceiver control mode 4 3 transceiver mode control modes table 4 2 two wire mode DTR controlled 4 2 two wire mode DTR with Echo 4 2 two wire mode TXRDY auto control 4 3 bits per second 3 3 C cable connection 2 8 changing communication port settings 3 1 changing resources assigned to PCMCIA serial cards C 6 common questions C 5 changing resources assigned to PCMCIA serial cards C 6 determining port associated with COMx C 5 determining type of serial hardware installed C 5 determining version of NI Serial software installed C 5 diagnostic test failure C 5 maximum supported baud rate C 7 National Instruments Corporation naming National Instruments serial ports C 5 removing information about PCMCIA serial cards from the device manager C 7 communication port settings 3 1 viewing or changing 3 1 configuration 3 1 conflict free resources C 2 selecting C 2 connecting cables 2 8 connecting two wire devices 2 9 conventions xi customer education E 1 D data bits 3 3 DB 9 pin descriptions table 2 8 pin locations figure 2 8 DCE vs DTE A 5 default restoration 3 4 determining port associated with COMx 2 7 C 5 determining type of serial hardware installed C 5 determining version of NI Serial software installed C 5 development tools for saving time 1 4 devi
31. er tab and click on the View devices by type button Double click on the Multi function adapters icon From the Multi function adapters list double click on the serial interface that you want to change Click on the Resources tab B Note To change the resources of ports on two port or four port PCMCIA cards from within the Device Manager you must open the Multi function adapters class and double click on the name of your interface Use the Resources page to change the resources Any resource changes are automatically reflected to the child devices 6 Uncheck the Use automatic settings checkbox and click on the Change Setting button If the system does not allow you to change the settings select the configuration that gives you a conflict free base address and interrupt level from the Setting based on list box Click on the OK button to save your changes Troubleshooting Diagnostic Messages This section lists possible Diagnostic error messages along with solutions PCMCIA Serial for Windows Me 9x If the No National Instruments serial port found error message appears refer to Chapter 2 Installation and Verification and follow these troubleshooting steps 1 Verify the hardware resources 2 In some versions of Windows Me 9x the Driver tab in the Device Manager gives you the information about the driver installed Verify that the National Instruments serial driver is installed for the port 3 If either the serial h
32. eriod of one year from the date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this e
33. es Worldwide Support National Instruments has offices located around the world to help address your support needs You can access our branch office Web sites from the Worldwide Offices section of ni com Branch office Web sites provide up to date contact information support phone numbers e mail addresses and current events If you have searched the technical support resources on our Web site and still cannot find the answers you need contact your local office or National Instruments corporate Phone numbers for our worldwide offices are listed at the front of this manual PCMCIA Serial for Windows Me 9x E 2 ni com Glossary Prefix Meaning Value p pico 10 2 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 t tera 10 degrees Q ohms percent A amperes ANSI American National Standards Institute b bits B bytes baud bits per second bps bits per second C Celsius COM Computer Output Microform used in reference to a communication port CTS clear to send DB xx subminiature D connector where xx is the number of pins National Instruments Corporation G 1 PCMCIA Serial for Windows Me 9x Glossary DCD DCE DLL DMA DSR DTE DTR duplex EIA EMI FCC FIFO ft GND HSI HSO VO IRQ ISA Kbaud data carrier detect data communications equipment or data circuit terminating equipment dynamic link library direct memory acce
34. ess communications from interference The FCC places digital electronics into two classes These classes are known as Class A for use in industrial commercial locations only or Class B for use in residential or commercial locations Depending on where it is operated this product could be subject to restrictions in the FCC rules In Canada the Department of Communications DOC of Industry Canada regulates wireless interference in much the same way Digital electronics emit weak signals during normal operation that can affect radio television or other wireless products By examining the product you purchased you can determine the FCC Class and therefore which of the two FCC DOC Warnings apply in the following sections Some products may not be labeled at all for FCC if so the reader should then assume these are Class A devices FCC Class A products only display a simple warning statement of one paragraph in length regarding interference and undesired operation Most of our products are FCC Class A The FCC rules have restrictions regarding the locations where FCC Class A products can be operated FCC Class B products display either a FCC ID code starting with the letters EXN Trado Nane Medel Kunder or the FCC Class B compliance mark that appears as shown here on the right E Cooe FC with FCC Standards Consult the FCC web site http www fcc gov for more information FCC DOC Warnings This equipment generates and uses radio freq
35. ino e cecil tev R tisha 3 4 Restore Defa ltsi sneinen kininon a a ites a E A 3 4 Chapter 4 Using Your Serial Hardware General Programming Requirements ssesesseessessseeseetsrtstesestestesertnsretesteresteserresrssest 4 1 Advanced Transceiver Control for the PCMCIA 485 esssseessesesresreersrrereresrrerssrereees 4 1 Fo r Ware Mode i a sc a oiea E E tie EEE EE E ANEETA OASE AEI 4 2 Two Wire Mode DTR with Echo ccccsccsssssssssssssscsssssssessenesssseseessseesescesesees 4 2 Two Wire Mode DTR Controlled c csscsscsssessecssssessssssscstssssassassececssanes 4 2 Two Wire Mode TXRDY Auto Control eeeeesessesseeeeseeeeeeeeeeeeceeneeees 4 3 Setting the Transceiver Control Mode 00 cece eee eseeseeceseeseeeeescnseeeseeeneees 4 3 Setting the Transceiver Mode with DeviceloControl eee eee 4 4 Appendix A Serial Port Information Appendix B Uninstalling the Hardware and Software Appendix C Troubleshooting and Common Questions Appendix D Specifications Appendix E Technical Support Resources Glossary Index PCMCIA Serial for Windows Me 9x viii ni com Contents Figures Figure 2 1 Add Remove Programs Properties Dialog BoX eee eee eeeeeees 2 1 Figure 2 2 NI Serial Setup Screen oo eee ee ceceseceeceeeeecsseeeeeeeeseeesesaeensesseenaes 2 2 Figure 2 3 Inserting a PCMCIA Serial Card eee eeeseeeceeeeneenseeneeneeeseeeees 2 3 Figure 2 4 Device Manager Ports List for PCMCIA Serial Card Correctly
36. interrupted to read the data The Transmit Buffer control sets the maximum number of bytes written to the FIFO in a block when the PC is interrupted to write the data When you configure FIFO settings consider the following points e You can select larger FIFO buffer sizes to reduce the number of interrupts your PC receives and therefore minimize system overhead e If transfer rates are high you can lower the Receive Buffer value to prevent overrun errors due to interrupt latency e If your data transfer sizes are small and your Receive Buffer value is above your data sizes your system is less efficient Therefore set the Receive Buffer value below your data sizes Note If you want your serial hardware ports to use the names COM1 COM2 COM3 or COM4 refer to the Common Questions section of Appendix C Troubleshooting and Common Questions To reset the fields to their default values at any time click on the Restore Defaults button PCMCIA Serial for Windows Me 9x 3 4 ni com Using Your Serial Hardware This chapter describes how to set the hardware transceiver control mode for your RS 485 interfaces and lists some general programming requirements General Programming Requirements The NI Serial software is fully integrated into the standard Windows Me 9x communications software NI serial ports are used like any other Windows Me 9x communications COM port Windows Me 9x has standard communication functions for use
37. ive them access to the bus In a typical full duplex system one transmission line connects the bus master transmitter to all of the slave receivers A second transmission line connects all of the slave transmitters to the bus master receiver Because each transmission line has two separate wires a full duplex system is often referred to as a four wire system Figure A 1 shows a typical full duplex system National Instruments Corporation A 3 PCMCIA Serial for Windows Me 9x Appendix A Serial Port Information Slave 1 Slave 2 Slave n Rx Rx Rx MASTER SS Figure A 1 Typical Full Duplex System Half Duplex A typical half duplex multidrop bus architecture also involves a master slave protocol However in a half duplex system all transmitters and receivers are connected to the same transmission line A half duplex system is often referred to as a two wire system Figure A 2 shows a typical half duplex system MASTER Figure A 2 Typical Half Duplex System PCMCIA Serial for Windows Me 9x A 4 ni com Appendix A Serial Port Information Termination Because each differential pair of wires is a transmission line you must properly terminate the line to prevent reflections A common method of terminating a two wire multidrop RS 485 network is to install terminating resistors at each end of the multidrop network If you daisy ch
38. nge the base address refer to the Selecting Conflict Free Resources section earlier in this appendix How do I change the resources assigned to PCMCIA two port or four port serial cards Because the two port PCMCIA cards are single physical devices that support multiple ports they are registered as multi function adapters in the Device Manager Each port is a child device listed under Ports COM amp LPT Windows Me 9x does not allow the resources of the multi function child devices to be changed directly To change the resources of ports on two port PCMCIA cards from within the Device Manager you must open the Multi function adapters class and double click on the Multi function Parent item that corresponds to your National Instruments serial interface Use the Resources page to change the resources Any resource changes are automatically reflected to the child devices Figure C 2 shows the Multi function adapters class in the Device Manager PCMCIA Serial for Windows Me 9x C 6 ni com Appendix C Troubleshooting and Common Questions System Properties 21 x General Device Manager Hardware Profiles Performance View devices by type C View devices by connection E 3 Keyboard Modem m Monitor A Mouse lt gt Multifunction adapters NI PCMCIA 232 Multi function Parent EF Network adapters Other devices PCMCIA socket oY Ports COM amp LPT J Communications Port COM1 F N I POMCIA 232 2 Communication
39. ode the serial hardware transparently enables the transmitter and receiver in a two wire system Use this mode to remove the burden of flow control from your application By connecting the transmitter to the TXRDY Transmit Ready line the hardware enables the transmitter for each byte to be transmitted Also the hardware disables the receiver whenever the transmitter is enabled so you do not receive the packets sent from your transmitter Sy Note When you are communicating with a two wire device National Instruments recommends that you use the two wire TXRDY auto control mode Because this mode handles the transmitter receiver enabling for a two wire connection in your hardware it reduces the software overhead required to perform this operation in your application program For more information about serial communication in two or four wire modes refer to the Serial Communication Issues section in Appendix A Serial Port Information Setting the Transceiver Control Mode The recommended method for setting the transceiver control mode is with the serial configuration utility located in the Windows Me 9x Device Manager For more information refer to the View or Change Communication Port Settings section in Chapter 3 Configuration The mode you select in the Device Manager is automatically configured when you open a port on a Serial interface You can also set the hardware transceiver control mode from within a DOS application For each por
40. onal Instruments Corporation A 1 As specified in the ANSI EIA 232 D Standard Interface Between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange RS 232 standardizes serial communication between computers and between computer terminals and modems Most applications use the RS 232 standard to interface peripherals to personal computers RS 232 uses transmission lines in which the state of each signal is represented by referencing the voltage level of a single line to ground RS 232 was designed for serial communication up to PCMCIA Serial for Windows Me 9x Appendix A Serial Port Information RS 422 distances of 50 ft and with data rates up to 20 kbytes s However because of improvements in line drivers and cabling you can usually increase the actual performance of the bus past the limitations on speed and distance recommended in the specification RS 485 As specified in the E A RS 422 A Standard Electrical Characteristics of Balanced Voltage Digital Interface Circuits RS 422 defines a serial interface much like RS 232 However RS 422 uses balanced or differential transmission lines Balanced transmission lines use two transmission lines for each signal The state of each signal is represented not by a voltage level on one line referenced to ground as in RS 232 but rather by the relative voltage of the two lines to each other For example the TX signal is carried on t
41. ons Online problem solving and diagnostic resources include frequently asked questions knowledge bases product specific troubleshooting wizards manuals drivers software updates and more Web support is available through the Technical Support section of ni com NI Developer Zone The NI Developer Zone at ni com zone is the essential resource for building measurement and automation systems At the NI Developer Zone you can easily access the latest example programs system configurators tutorials technical news as well as a community of developers ready to share their own techniques Customer Education National Instruments provides a number of alternatives to satisfy your training needs from self paced tutorials videos and interactive CDs to instructor led hands on courses at locations around the world Visit the Customer Education section of ni com for online course schedules syllabi training centers and class registration System Integration If you have time constraints limited in house technical resources or other dilemmas you may prefer to employ consulting or system integration services You can rely on the expertise available through our worldwide network of Alliance Program members To find out more about our Alliance system integration solutions visit the System Integration section of ni com National Instruments Corporation E 1 PCMCIA Serial for Windows Me 9x Appendix E Technical Support Resourc
42. or two wire communication refer to Chapter 4 Using Your Serial Hardware For more information about duplex architectures refer to Appendix A Serial Port Information National Instruments Corporation 2 9 PCMCIA Serial for Windows Me 9x Configuration This chapter describes how to view or change the communication port settings View or Change Communication Port Settings The serial configuration utility is fully integrated with the Windows Me 9x Device Manager You can use it to examine or modify the configuration of the serial port Follow these steps to configure the serial port Repeat the configuration procedure for each serial port in your system 1 Select Start Settings Control Panel and double click on the System icon The System Properties window appears 2 Select the Device Manager tab and click on the View devices by type button at the top of the page Double click on the Ports COM amp LPT icon 4 Double click on the name of the port you want to configure You can now view or change information about your serial port in the following ways e Click on the Resources tab to view information about the hardware resources assigned to the serial port e Click on the Port Settings tab to view information about the software configuration for the serial port Refer to the next section Port Settings Tab for more information e On the Port Settings tab click on the Advanced button to change the RS 485
43. otes a note which alerts you to important information Bold text denotes items that you must select or click on in the software such as menu items and dialog box options Bold text also denotes parameter names Signal names with an overscore such as DTR indicate that the signal is active low Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts Bold text in this font denotes the messages and responses that the computer automatically prints to the screen This font also emphasizes lines of code that are different from the other examples National Instruments Corporation xi PCMCIA Serial for Windows Me 9x About This Manual Related Documentation The following documents contain information that you might find helpful as you read this manual PCMCIA Serial for Windows Me 9x ANSI EIA 232 D Standard Interface Between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange EIA RS 422 A Standard
44. ource conflict exists If no circled exclamation point appears the serial hardware is installed correctly Figure 2 4 shows an example of NI serial hardware that is installed properly and Figure 2 5 shows an example of NI serial hardware that is not working properly PCMCIA Serial for Windows Me 9x 2 4 ni com Chapter 2 Installation and Verification System Properties Keyboard Modem Monitor Mouse lt gt Multi function adapters Q NI PEMCIA 232 Multi function Parent E9 Network adapters Other devices PCMCIA socket a Ports COM amp LPT y Communications Port COM1 e F N I POMCIA 232 2 Communications Port COM5 aee Kj N I PEMCIA 232 2 Communications Port COMB ov Printer Port LPT2 A Sound video and game controllers W YAMAHA OPL3 SAx GamePort Figure 2 4 Device Manager Ports List for PCMCIA Serial Card Correctly Installed National Instruments Corporation 2 5 PCMCIA Serial for Windows Me 9x Chapter 2 Installation and Verification System Properties REI General Device Manager Hardware Profiles Performance View devices by type View devices by connection amp Disk drives w Display adapters Sy Floppy disk controllers Sy Hard disk controllers E Keyboard amp Modem a Monitor A Mouse lt gt Multifunction adapters NI PEMCIA 232 Multi function Parent BY Network adapters amp Other devices PCMCIA socket Y Ports COM amp LPT Sound video and game controllers
45. ows CVI After you install your serial hardware and the NI Serial software you can use standard serial I O functions in LabVIEW and LabWindows CVI with your serial interface If you already have LabVIEW or LabWindows CVI and want to use it with your serial hardware refer to your LabVIEW or LabWindows CVI documentation for information about serial I O functions PCMCIA Serial for Windows Me 9x 1 4 ni com Installation and Verification This chapter describes how to install the NI Serial software serial hardware and cables and how to verify the installation Install the Software Install the NI Serial software for Windows Me 9x before you install the hardware 1 Select Start Settings Control Panel 2 Double click on the Add Remove Programs icon in the Control Panel to launch the Add Remove Programs applet A dialog box similar to the one in Figure 2 1 appears Add Remove Programs Properties 27 x Install Uninstall windows Setup Startup Disk al To install a new program from a floppy disk or CD ROM drive click Install 22 The following software can be automatically removed by te Windows To remove a program or to modify its installed components select it from the list and click Add Remove Netscape Navigator Paint Shop Pro Version 3 12 SoftICE for Windows 95 Add Remove OK Cancel Apply Figure 2 1 Add Remove Programs Properties Dialog Box National Instruments Corpo
46. ows CVI 1 4 using with serial hardware 1 4 legacy boards C 3 resolving resource conflicts with C 3 maximum supported baud rate C 7 multidrop network using terminating resistors figure A 5 multi function adapter class in the Device Manager figure C 7 naming National Instruments serial ports C 5 standard DOS based addresses table C 5 National Instruments Web support E 1 NI Developer Zone E 1 ni com NI Serial setup screen figure 2 2 null modem cabling in a DTE to DTE interface figure A 6 0 optional equipment 1 2 overview of serial hardware 1 2 overview of serial software 1 3 P parity 3 3 PCMCIA 485 advanced transceiver control for 4 1 setting transceiver control mode 4 3 transceiver mode control modes table 4 2 two wire mode DTR controlled 4 2 two wire mode DTR with Echo 4 2 two wire mode TXRDY auto control 4 3 physical characteristics D 1 pin descriptions DB 9 connector pin descriptions table 2 8 connector pin locations figure 2 8 port settings tab 3 2 figure 3 2 options advanced port settings 3 3 bits per second 3 3 data bits 3 3 flow control 3 3 parity 3 3 stop bits 3 3 restore defaults button 3 4 ports list in device manager tab figure C 4 National Instruments Corporation Index R related documentation xii removing information about PCMCIA serial cards from the device manager C 7 resolving resource conflicts with legacy boar
47. ration 2 1 PCMCIA Serial for Windows Me 9x Chapter 2 Installation and Verification PCMCIA Serial for Windows Me 9x Click on the Install button When prompted insert the N Serial Software for Windows 2000 NT Me 9x CD and click on the Next button to proceed The software installation wizard begins with the screen shown in Figure 2 2 NI Serial Software x Welcome to the NI Serial Software Setup program This program will install NI Serial Software on your computer It is strongly recommended that you exit all Windows programs before running this Setup program Click Cancel to quit Setup and then close any programs you have running Click Next to continue with the Setup program WARNING This program is protected by copyright law and international treaties Unauthorized reproduction or distribution of this program or any portion of it may result in severe civil and criminal penalties and will be prosecuted to the maximum extent possible under law Figure 2 2 Nl Serial Setup Screen The setup wizard guides you through the necessary steps to install the NI Serial software You can go back and change values where appropriate by clicking on the Back button You can exit the setup where appropriate by clicking on the Cancel button If you need to install your hardware or if this is your first time to install the NI Serial software for Windows Me 9x skip to the next section Install the Hardware Otherwise con
48. rop network using terminating resistors figure A 5 time saving development tools 1 4 transceiver control modes table 4 2 transceiver mode 3 4 setting with DeviceloControl 4 4 transceiver mode control bytes figure 4 3 troubleshooting C 1 diagnostic messages C 2 forcing Windows to detect your hardware C 3 freeing an interrupt request level C 1 resolving resource conflicts with legacy boards C 3 selecting conflict free resources C 2 PCMCIA Serial for Windows Me 9x l 4 two wire devices 2 9 connecting 2 9 typical full duplex system figure A 4 typical half duplex system figure A 4 U uninstalling serial hardware B 1 uninstalling serial software B 3 using FIFO buffers 3 4 using serial hardware 4 1 using this manual 1 1 V verifying hardware installation 2 4 verifying hardware resources 2 6 viewing or changing communication port settings 3 1 W Web support from National Instruments E 1 Win32 Overviews and Win32 Reference 4 1 Win32 Software Development Kit 4 1 worldwide technical support E 2 ni com
49. rted 3 Note Signal names with an overscore such as DTR indicate that the signal is active low Four Wire Mode Use the four wire mode for most full duplex systems In this mode the transmitter and receiver are always enabled This mode is the default Two Wire Mode DTR with Echo Use this mode in half duplex systems where the DTR Data Terminal Ready line must control the transmitter In the DTR with echo mode the transmitter is tri stated when the DTR signal of the UART Universal Asynchronous Receiver Transmitter is asserted To transmit your application must first clear the DTR bit to enable the transmitter After the data is fully transmitted your application once again sets the DTR bit to disable the transmitter Because the receiver is always enabled in this mode you not only receive packets from other devices you also receive the packets sent from your transmitter Two Wire Mode DTR Controlled This mode is similar to the two wire DTR with echo mode Use this mode in half duplex systems where the DTR line must control the transmitter Although this mode uses the same method as the DTR with echo mode to control the transmitter the hardware automatically disables the receiver whenever the transmitter is enabled Thus you do not receive the packets sent from your transmitter PCMCIA Serial for Windows Me 9x 4 2 ni com Chapter 4 Using Your Serial Hardware Two Wire Mode TXRDY Auto Control In this m
50. s Corporation 2 3 PCMCIA Serial for Windows Me 9x Chapter 2 Installation and Verification Verify the Installation When you begin to verify the installation keep in mind that the serial ports built into the computer are typically named from COM1 to COM4 Windows Me 9x typically issues port names to the ports on NI serial hardware starting with COM5 COM6 and so on If not enough resources are available to assign to all the NI serial ports the port with the higher COM lt x name is left unconfigured Double click on the System icon in the Control Panel In the System Properties window that appears select the Device Manager tab and click on the View devices by type button at the top of the page If necessary double click on the Ports COM amp LPT icon to view all of the ports The two port and four port PCMCIA cards are configured as devices belonging to the multi function adapters class The multi function parent device is listed under the Multi function adapters icon and each child device is listed as a port under the Ports COM amp LPT icon If you have installed one of these interfaces double click on the Multi function adapters icon as well as the Ports COM amp LPT icon If a circled exclamation point appears through the port icon the serial port is not installed properly A problem with the port could have occurred because Windows Me 9x could not acquire resources for the port or because an interrupt request res
51. s Port COMS N I PCMCIA 232 2 Communications Port COM6 a Printer Port LPT2 E A Sound video and game controllers YAMAHA OPL3 SAx GamePort SAP OMAA a O manad Oe Properties Refresh Remove Print E Figure C 2 Multi Function Adapter Class in the Device Manager How do I remove information about PCMCIA two port or four port serial cards from the Device Manager Because the two port PCMCIA cards are single physical devices that support multiple ports they are registered as multi function adapters in the Device Manager Each port is a child device listed under Ports COM amp LPT Windows Me 9x does not allow multi function child devices to be removed directly within the Device Manager You must open the Multi function adapters class as shown in Figure C 2 select your interface and click on the Remove button What is the maximum baud rate supported and how can I set it The maximum baud rate supported is 460 8 Kbaud for RS 485 and 115 2 Kbaud for RS 232 To set the baud rate use the SetCommState Win32 function and pass the actual value of the baud rate in the BaudRate field of the DCB structure National Instruments Corporation C 7 PCMCIA Serial for Windows Me 9x Specifications This appendix describes the characteristics of the serial hardware the NI Serial software along with the recommended operating conditions Hardware Specifications Table
52. ss data set ready data terminal equipment data terminal ready the overscore denotes that the signal is active low the means of bandwidth usage in a serial system Electronic Industries Association electromagnetic interference Federal Communications Commission First In First Out feet ground handshake input handshake output Hertz Institute of Electrical and Electronic Engineers inches input output interrupt request Industry Standard Architecture kilobits per second meters PCMCIA Serial for Windows Me 9x G 2 ni com MB PC PCI RAM RI RTS RX RXD SCSI TX TXD TXRDY UART VDC VXI Winl6 Win32 Glossary megabytes of memory personal computer Peripheral Components Interconnect random access memory ring indicator request to send receive receive data the overscore denotes that the signal is active low seconds Small Computer Systems Interface transmit transmit data the overscore denotes that the signal is active low transmit ready the overscore denotes that the signal is active low Universal Asynchronous Receiver Transmitter volts volts direct current VME eXtensions for Instrumentation describes a 16 bit Windows application describes a 32 bit Windows application National Instruments Corporation G 3 PCMCIA Serial for Windows Me 9x Index A add remove programs properties dialog box figure 2 1 B 3 advanced port settings 3 3 dialog box figure 3 3 transceiv
53. t you want to control write the control byte for the mode you want to select to the scratch register of the UART Table 4 2 shows the control bytes for each mode Table 4 2 Transceiver Mode Control Bytes Transceiver Mode Control Byte Four wire mode 0x00 Two wire mode DTR with echo 0x01 Two wire mode DTR controlled 0x02 Two wire mode TXRDY auto control 0x03 National Instruments Corporation 4 3 PCMCIA Serial for Windows Me 9x Chapter 4 Using Your Serial Hardware The scratch register is located at offset 7 from the base address of the port For example if COM2 were located at base address 0x3F8 and you wanted to set the PCMCIA 485 board to two wire mode with DTR control you would write a 0x02 to I O address Ox3FF The PCMCIA 485 board would immediately switch to the two wire mode with DTR control Setting the Transceiver Mode with DeviceloControl The NI Serial software extends the DeviceIoCont rol Windows function for programming the transceiver control mode To program the transceiver control mode using DeviceIoControl complete the following steps 1 Add the following lines to your source code include lt winioctl h gt define IOCTL SERIAL SET TRANSCEIVER MODE CTL CODE FILE DEVICE SERIAL PORT 37 METHOD BUFFERED FILE ANY ACCESS 2 Use the Win32 function DeviceIoControl as follows a Use the defined control code value listed in step 1 to set the transceiver mode b Us
54. tall the Hardware Before physically removing the serial hardware you must remove the hardware information from the Windows Me 9x Device Manager Follow these steps to uninstall the hardware 1 Double click on the System icon under Start Settings Control Panel The System Properties dialog box appears 2 Select the Device Manager tab Click on the View devices by type button 4 Double click on the Ports COM amp LPT icon National Instruments Corporation B 1 PCMCIA Serial for Windows Me 9x Appendix B Uninstalling the Hardware and Software 5 Select the National Instruments port to remove from the list of ports as shown in Figure B 1 System Properties 27 x General Device Manager Hardware Profiles Performance View devices by type View devices by connection E Keyboard Modem m Monitor A Mouse lt gt Multi function adapters Se Multi function Parent BY Network adapters 9 Other devices PCMCIA socket oY Ports COM amp LPT a Communications Port COM1 N I PCMCIA 232 4 Communications Port COM5 N I PCMCIA 232 4 Communications Port COME i N I POMCIA 232 4 Communications Port COM N I PCMCIA 232 4 Communications Port COM8 Printer Port LPT 2 ae e a ee ee eet operties Refresh Remove z 20 gy eS peo gy a F F omes Figure B 1 Selecting an Interface to Uninstall 6
55. tinue to Step 6 If your hardware is already installed restart Windows Me 9x Windows Me 9x should automatically detect your hardware and display one or more New Hardware Found dialog boxes When you finish continue to the Verify the Installation section If no New Hardware Found dialog box appears refer to the section Forcing Windows to Detect Your Hardware in Appendix C Troubleshooting and Common Questions 2 2 ni com Chapter 2 Installation and Verification Install the Hardware To install the PCMCIA 232 or PCMCIA 485 in your computer first start Windows Me 9x If the card is not already inserted insert it into a free PC Card PCMCIA socket the same way you insert a disk into a floppy drive The card has no jumpers or switches to set and you do not need to shut down the system before you insert it Windows Me 9x automatically displays one or more New Hardware Found dialog boxes when it detects and configures a PC Card If the New Hardware Found dialog box does not appear refer to the Forcing Windows to Detect Your Hardware section in Appendix C Troubleshooting and Common Questions Figure 2 3 shows how to insert a PCMCIA serial card and how to connect the cable Portable Computer PCMCIA Socket PCMCIA Serial Cable Figure 2 3 Inserting a PCMCIA Serial Card The serial hardware installation is complete Continue to the next section Verify the Installation National Instrument
56. transceiver mode and to enable or disable the FIFOs on the serial hardware Refer to the next section Port Settings Tab for more information ay Note If you use two wire TXRDY mode FIFOs must be enabled Transceiver modes apply to RS 485 interfaces only For more information about transceiver modes refer to Chapter 4 Using Your Serial Hardware National Instruments Corporation 3 1 PCMCIA Serial for Windows Me 9x Chapter3 Configuration After you have selected the serial port parameters for the current port click on the OK button to save the changes or click on the Cancel button to exit the dialog box without saving changes Port Settings Tab On the Port Settings tab you can change any of the settings by clicking on the arrow button to the right of the setting When you click on the arrow button a list of valid values for that setting appears Select the desired setting from the list Figure 3 1 shows the Port Settings tab N I PCMCIA 232 2 Communications Port COM2 Pro KA Eg Figure 3 1 Port Settings Tab The following sections describe the options you can set in the Device Manager Port Settings tab PCMCIA Serial for Windows Me 9x 3 2 ni com Bits per Second Chapter 3 Configuration Bits per second or baud rate is the speed for a serial port Data Bits Data bits is the number of data bits in a single serial byte Parity Parity is the specification for even odd or no parity
57. ty e Configuration utility e Product manuals The NI Serial software supports all National Instruments serial hardware including the AT PCI PXI CompactPCI and PCMCIA versions National Instruments Corporation 1 3 PCMCIA Serial for Windows Me 9x Chapter 1 Introduction Time Saving Development Tools Your kit includes the NI Serial software for Windows Me 9x In addition you can order the LabWindows CVI or LabVIEW software from National Instruments to speed your application development time and make it easier to communicate with your instruments LabVIEW is an easy to use graphical programming environment you can use to acquire data from thousands of different instruments including IEEE 488 2 devices VXI devices serial devices PLCs and plug in data acquisition boards After you have acquired raw data you can convert it into meaningful results using the powerful data analysis routines in LabVIEW LabVIEW also comes with hundreds of instrument drivers which dramatically reduce software development time because you do not have to spend time programming the low level control of each instrument LabWindows CVI is similar to LabVIEW except that it combines an interactive easy to use development approach with the programming power and flexibility of compiled ANSI C code For ordering information or to request free demonstration software contact National Instruments Using Your Serial Hardware with LabVIEW and LabWind
58. uency energy and if not installed and used in strict accordance with the instructions in this manual and the CE Mark Declaration of Conformity may cause interference to radio and television reception Classification requirements are the same for the Federal Communications Commission FCC and the Canadian Department of Communications DOC FOR HOME OR OFFICE USE Changes or modifications not expressly approved by National Instruments could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission This equipment has been tested and found to comply with the limits for a 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 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 which case the user will be required to correct the interference at his own expense Canadian Department of Communications This Class A digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe A respecte toutes les exigences du R glement sur l
59. ves Readers in the EU EEC EEA must refer to the Manufacturer s Declaration of Conformity DoC for information pertaining to the CE Mark compliance scheme The Manufacturer includes a DoC for most every hardware product except for those bought for OEMs if also available from an original manufacturer that also markets in the EU or where compliance is not required as for electrically benign apparatus or cables Certain exemptions may apply in the USA see FCC Rules 15 103 Exempted devices and 15 105 c Also available in sections of CFR 47 The CE Mark Declaration of Conformity will contain important supplementary information and instructions for the user or installer Contents About This Manual GOMVEMELOIS erenn cobevien fo chaebe dea sahe cn EE cone psedued ab sosuus stan sceedocusheveueeuizens xi Related DocumentatiOM sen r a a a a A A dia xii Chapter 1 Introduction How to Use This Man aleniin usien ee E a e e a EASi 1 1 What You Need to Get Started oeseseseeeereeeersesessseserererereererrersssssssesssrerrererereeeeeeesesses 1 2 Optional Equipment nooo a Aa EEK TEA ER R ERR 1 2 Serial Hardware OvervieW sseseeeeeerreesssesssessssrererererrrerrrsssssssssstterrrtetetreereersrsssssssent 1 2 NI Serial Software Overview ecesessseesererrrsssrsrsssssssesererereerereeressesssssessserereerereeeeeeeesess 1 3 Time Saving Development Tools ee eeeescceceseseeeeseseeeeseceesaecaecesecseeesecaeensesaeenaes
60. within either Win16 or Win32 applications When you develop your application remember that you must use the standard Microsoft Windows serial communication functions For information about Microsoft Windows serial communication functions refer to the Win32 Software Development Kit and to the Win32 Overviews and Win32 Reference online help If you have LabVIEW or LabWindows CVI and want to use it with your serial hardware refer to your LabVIEW or LabWindows CVI documentation for information about serial I O functions Advanced Transceiver Control for the PCMCIA 485 Ss Note Transceiver modes apply only to the PCMCIA 485 boards The PCMCIA 485 boards support four modes of hardware transceiver control You can use hardware flow control to enable and disable your transmitters and receivers so that they function on different bus topologies Table 4 1 lists the status of the transmitters and receivers under each of the transceiver control modes National Instruments Corporation 4 1 PCMCIA Serial for Windows Me 9x Using Your Serial Hardware Table 4 1 Transceiver Control Modes Mode Transmitter Receiver Four wire mode Always enabled Always enabled Two wire mode Enabled with Always enabled DTR with echo DTR unasserted Two wire mode Enabled with Enabled with DTR controlled DTR unasserted DTR asserted Two wire mode Enabled with Enabled with TXRDY auto control TXRDY asserted TXRDY unasse
61. wo wires wire A and wire B A logical is represented by the voltage on line A being greater than the voltage on line B A logical 0 is represented by the voltage on line A being less than the voltage on line B Differential voltage transmission creates a signal that is more immune to noise as well as voltage loss due to transmission line effects Thus you can use RS 422 for longer distances up to 4 000 ft and greater transmission speeds up to 10 Mbytes s than RS 232 As specified in the E A 485 Standard Standard for Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multipoint Systems RS 485 expands on the RS 422 standard by increasing the number of devices you can use from 10 to 32 and by working with half duplex bus architectures Unlike the RS 422 standard RS 485 addresses the issue of using multiple transmitters on the same line RS 485 defines the electrical characteristics necessary to ensure adequate signal voltages under maximum load short circuit protection RS 485 can also withstand multiple drivers driving conflicting signals at the same time PCMCIA Serial for Windows Me 9x A 2 ni com Appendix A Serial Port Information Serial Communication Issues This section explains some serial communication issues including duplex architectures termination methods bias resistors and types of connecting equipment Duplex Architectures Duplex refers to the means of bandwidth usage in a seri

National Instruments 321827C-01 User's Manual

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