GPIB-140A User Manual - National Instruments
Contents
1. Note You cannot use the GPIB 140A or GPIB 140A 2 bus extenders to communicate with either a GPIB 140 or GPIB 140 2 bus extender The GPIB 140A and GPIB 140A 2 bus extenders use a different protocol to communicate with each other across the fiber optic cable The GPIB 140A and GPIB 140A 2 are high speed bus extenders that you can use in pairs with fiber optic cable to connect two separate GPIB systems in a functionally transparent manner Although the two bus systems are physically separate as shown in Figure 1 1 devices logically appear to be located on the same bus as shown in Figure 1 2 Figure 1 1 Typical Extension System Physical Configuration GPIB Cable Printer Listener E Computer System Controller Talker and Listener GPIB Cable GPIB 140A or GPIB 140A or GPIB 140A 2 J GPIB 140A 2 ae T a GPIB Cable ein Fiber Optic Cable css Multimeter Talker and Listener Signal Generator Uni Under te i Listener Figure 1 2 Typical Extension System Logical Configuration Talker and Listener GPIB Computer z System Controller Printer Multimeter Signal Generator Listener Talker and Listener Listener 1 2 ni com Unit Under Test GPIB 140A User Manual The GPIB 140A and GPIB 140A2. requirements for special EMC environments such as for marine use or in heavy industrial areas Refer to the hardware s user documentation and the DoC for product installation requirements When the hardware is connected to a test object or to test leads the system may become more sensitive to disturbances or may cause interference in the local electromagnetic environment Operation of this hardware in a residential area is likely to cause harmful interference Users are required to correct the interference at their own expense or cease operation of the hardware Changes or modifications not expressly approved by National Instruments could void the user s right to operate the hardware under the local regulatory rules The Declaration of Conformity DoC contains important EMC compliance information and instructions for the user or installer To obtain the DoC for this product visit ni com certification search by model number or product line and click the appropriate link in the Certification column Contents About This Manual CONVENT ONS sa i a Rn AS ix Related Documentation viziilione ian ione lun inietta ix Chapter 1 Introduction What Your Kit Should Contain ptional Equipm nt ilriencnaiieluulila lella lia Hardware Overview Time Saving Development Tools Chapter 2 Connecting Your Hardware Step 1 Verify the DIP Switch Setting iii Step
3. 0 GOTO 300 Selecting a PPR Mode To select a PPR mode consider the type of Controller present in your GPIB system and the length of cable between the GPIB 140A extenders However if your application does not use parallel polls you do not need to select a PPR mode Some Hewlett Packard GPIB Controllers remain in a parallel poll state with IDY asserted if they are not performing another function A change in the response interrupts the application In some Controllers the IDY signal is toggled on and off and you can change the duration of the signal to accommodate delayed responses over extenders If you are using these types of Controllers you should set the GPIB extender to immediate PPR mode Most other Controllers pulse the IDY signal for approximately 2 us and expect a response within that time If you are using this type of Controller and if the cable between the extenders is longer than 60 m you should set the GPIB extender to latched PPR mode For shorter cable distances use immediate PPR mode The two GPIB extenders in your extension system do not need to use the same PPR mode Select the PPR mode of the local GPIB extender based on the Controllers on the local GPIB system Likewise select the PPR mode of the remote GPIB extender based on the Controllers on the remote GPIB system If no Controllers are physically connected to one of the GPIB extenders the PPR mode of that GPIB extender has no effect on your system Setting t
4. The two GPIB extenders in your extension system do not need to use the same HS488 mode However the system uses the maximum data transfer rate when both sides in your extension system use HS488 3 2 ni com GPIB 140A User Manual To enable HS488 set DIP switch 2 to the ON position as shown in Figure 3 2 To disable HS488 set DIP switch 2 to the OFF position Figure 3 2 DIP Switch Setting for Enabled HS488 l Not used to set HS488 mode PARALLEL POLL IMMEDIATE HS488 ENABLE BUFFERED TRANSFER Parallel Poll Response Modes According to IEEE 488 devices must respond to a parallel poll within 200 ns after the Controller In Charge CIC asserts the Identify IDY message Attention ATN and End or Identify EOI The CIC waits at least 2 us before reading the Parallel Poll Response PPR In many cases a remote device on an extended system cannot respond to parallel polls this quickly because of cable propagation delays To solve this problem use one of the following two solutions in your application e Ifpossible specify in your application that the CIC must allow enough time to receive the response For more information refer to the following section Immediate PPR Mode If you are using the NI 488 2 software you can use the NI 488 2 Configuration utility to set the amount of time that the CIC waits e Execute two consecutive parallel polls and use the second response For more information refer to t
5. MLA30 1F 31 US CFE 3F 63 UNL 40 64 MTAO 60 96 MSAO PPE 41 65 A MTAI 61 97 a MSAI PPE CFGI 42 66 B MTA2 62 98 b MSA2 PPE CFG2 43 67 C MTA3 63 99 c MSA3 PPE CFG3 44 68 D MTA4 64 100 d MSA4 PPE CFG4 45 69 E MTAS 65 101 e MSAS PPE CFG5 46 70 F MTA6 66 102 f MSA6 PPE CFG6 47 71 G MTA7 67 103 MSA7 PPE CFG7 48 72 H MTA8 68 104 MSA8 PPE CFG8 49 73 I MTA9 69 105 i MSA9 PPE CFG9 4A 74 Ji MTA10 6A 106 j MSA 10 PPE CFG10 4B 75 K MTAI1 6B 107 k MSA11 PPE CFG11 4C 76 L MTA12 6C 108 1 MSA 12 PPE CFG12 4D 77 M MTA13 6D 109 m MSA 13 PPE CFG13 4E 78 N MTA14 6E 110 n MSA 14 PPE CFG14 4F 79 6 MTA15 6F 111 o MSA15 PPE CFG15 50 80 P MTA16 70 112 p MSA16 PPD 51 81 Q MTA17 71 113 q MSA17 PPD 52 82 R MTA18 72 114 r MSA 18 PPD C 2 ni com GPIB 140A User Manual Table C 1 Multiline Interface Messages Continued Hex Dec ASCII Message Hex Dec ASCII Message 53 83 S MTA19 73 115 s MSA19 PPD 54 84 T MTA20 74 116 t MSA20 PPD 55 85 U MTA21 75 117 u MSA21 PPD 56 86 Vv MTA22 76 118 v MSA22 PPD 57 87 W MTA23 77 119 w MSA23 PPD 58 88 X MTA24 78 120 x MSA24 PPD 59 89 Y MTA25 79 121 y MSA25 PPD SA 90 Z MTA26 TA 122 Z MSA26 PPD 5B 91 MTA27 7B 123 MSA27 PPD 5C 92 i MTA28 7C 124 MSA28 PPD 5D 93 MTA29 7D 125 MSA29 PPD SE 94 MTA30 TE 126 MSA30 PPD SF 95 UNT TF 12
6. Standard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation ANSI IEEE Standard 488 2 1992 IEEE Standard Codes Formats Protocols and Common Commands National Instruments ix Introduction This chapter lists the kit contents and briefly describes the GPIB 140A bus extender What Your Kit Should Contain Before you connect your GPIB 140A or GPIB 140A 2 make sure you have all of the following items One of the following GPIB 140A or GPIB 140A 2 bus extenders US 100 120 VAC Switzerland 220 240 VAC Australia 220 240 VAC Universal European 220 240 VAC North American 220 240 VAC U K 220 240 VAC Japan 100 VAC One of the following standard 3 wire power cables 100 120 VAC 220 240 VAC Optional Equipment One of the following transmission cables which you can purchase from National Instruments Type T7 fiber optic cable up to 1 km used with GPIB 140A Type T8 fiber optic cable up to 2 km used with GPIB 140A 2 Caution To meet FCC emission limits for this device you must use a shielded GPIB cable Ifyou operate this equipment with a non shielded cable it may interfere with radio and television reception A Type X2 double shielded cable 1 2 or 4 m which you can purchase from National Instruments National Instruments 1 1 Chapter 1 Introduc tion Hardware Overview
7. designed to provide reasonable protection against harmful interference when the hardware is operated in the intended electromagnetic environment In special cases for example when either highly sensitive or noisy hardware is being used in close proximity additional mitigation measures may have to be employed to minimize the potential for electromagnetic interference While this hardware is compliant with the applicable regulatory EMC requirements there is no guarantee that interference will not occur in a particular installation To minimize the potential for the hardware to cause interference to radio and television reception or to experience unacceptable performance degradation install and use this hardware in strict accordance with the instructions in the hardware documentation and the DoC If this hardware does cause interference with licensed radio communications services or other nearby electronics which can be determined by turning the hardware off and on you are encouraged to try to correct the interference by one or more of the following measures e Reorientthe antenna of the receiver the device suffering interference e Relocate the transmitter the device generating interference with respect to the receiver e Plug the transmitter into a different outlet so that the transmitter and the receiver are on different branch circuits Some hardware may require the use of a metal shielded enclosure windowless version to meet the EMC
8. devices The following restrictions are typical e A maximum separation of 4 m between any two devices and an average separation of 2 m over the entire bus A maximum total cable length of 20 m A maximum of 15 devices connected to each bus with at least two thirds powered on For high speed operation the following restrictions apply All devices in the system must be powered on e Cable lengths must be as short as possible with up to a maximum of 15 m of cable for each system e There must be at least one equivalent device load per meter of cable National Instruments A 5 Appendix A GPIB Basics If you want to exceed these limitations you can use a bus expander to increase the number of device loads You can order bus expanders from National Instruments A 6 ni com Introduction to HS488 This appendix describes HS488 and the sequence of events in high speed data transfers National Instruments has designed a high speed data transfer protocol for IEEE 488 called HS488 This protocol increases performance for GPIB reads and writes up to 8 Mbytes s depending on your system If HS488 is enabled the TNT4882C hardware implements high speed transfers automatically when communicating with HS488 instruments If you attempt to enable HS488 on a GPIB interface that does not have the TNT4882C hardware the ECAP error code is returned Objectives The following sections describe the objectives of HS488 Fast
9. in this manual aS A bold GPIB 140A GPIB 140A 2 GPIB extender IEEE 488 and IEEE 488 2 italic monospace This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash Bold text denotes the names of LEDs GPIB 140A refers to a National Instruments GPIB extender that extends the GPIB to a maximum distance of 1 km GPIB 140A 2 refers to a National Instruments GPIB extender that extends the GPIB to a maximum distance of 2 km GPIB extender refers to the GPIB 140A and the GPIB 140A 2 IEEE 488 and IEEE 488 2 refer to the ANSI IEEE Standard 488 1 1987 and the ANSI IEEE Standard 488 2 1992 respectively which define the GPIB Italic text denotes variables emphasis a cross reference or an introduction to a key concept Italic text 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 Related Documentation The following documents contain information that you might find helpful as you read this manual e ANSIIEEE
10. manages the flow of information on the bus It defines the communication links and sends GPIB commands to devices Some devices are capable of playing more than one role A digital voltmeter for example can be a Talker and a Listener If your system has a National Instruments GPIB interface and software installed it can function as a Talker Listener and Controller National Instruments A 1 Appendix A GPIB Basics The GPIB is like a typical computer bus except that the typical computer has circuit cards interconnected via a backplane bus whereas the GPIB has standalone devices interconnected via a cable bus The role of the GPIB Controller is similar to the role of the CPU of a computer but a better analogy is to the switching center of a city telephone system The switching center Controller monitors the communications network GPIB When the center Controller notices that a party device wants to make a call send a data message it connects the caller Talker to the receiver Listener The Controller addresses a Talker and a Listener before the Talker can send its message to the Listener After the message is transmitted the Controller may unaddress both devices Some bus configurations do not require a Controller For example one device may always be a Talker called a Talk only device and there may be one or more Listen only devices A Controller is necessary when the active or addressed Talker or Listener mus
11. reduce software overhead Also system throughput increases depend on data block size IEEE 488 1 Requirements for High Speed Operation T1 Delay gt 350 ns The IEEE 488 1 standard requires that devices used in high speed operation must use three state 48 mA drivers on most signals Each device must add no more than 50 pF capacitance on each signal and all devices must be powered on The total cable length in a system must be no more than 15 m or 1 m times the number of devices in the system HS488 System Requirements An HS488 system must meet the IEEE 488 1 requirements and it must implement the following three new interface functions e Talking devices must use the Source Handshake Extended SHE interface function which is an extension of the IEEE 488 1 SH function e Listening devices must use the Acceptor Handshake Extended AHE interface function which is an extension of the IEEE 488 1 AH function Accepting devices must have a buffer of at least 3 bytes to store received data e HS488 devices must implement the Configuration CF interface function At system power on the Controller uses previously undefined multiline messages to configure HS488 devices The CF function enables devices to interpret these multiline messages B 2 ni com GPIB 140A User Manual Sequence of Events in Data Transfers Figure B 1 shows a typical IEEE 488 1 data transfer Figure B 1 IEEE 488 1 Transfers IEEE 488 1 Three W
12. the sending Lack of low going transition on device is capable of sending data NRFD indicates that all receiving using the high speed handshake devices are high speed capable The Controller addresses devices and becomes Standby Controller by unasserting ATN The Listener asserts NDAC and NRFD The Listener unasserts NRFD as it becomes ready to accept a byte e ch After allowing time for the Listener to detect NRFD unasserted the Talker indicates that it is HS488 capable by sending the HSC message To send the HSC message true the Talker asserts the NRFD signal 5 After allowing time for the Listener to respond to the HSC message the Talker sends the HSC message false To send the HSC message false the Talker unasserts the NRFD signal 6 When the Talker has a byte ready to send it drives the data on the DIO signal lines allows some settling time and asserts DAV 7 The Listener unasserts NDAC HS488 capable Listeners do not assert NRFD as IEEE 488 1 devices would so the Talker determines that the addressed Listener is HS488 capable The Talker unasserts DAV and drives the next data byte on the GPIB After allowing some settling time the Talker asserts DAV 10 The Listener latches the byte in response to the assertion falling edge of DAV 11 After allowing some hold time the Talker unasserts DAV and drives the next data byte on the DIO signal lines 12 Steps 9 11 are repeated for each data byte B 4 ni c
13. 2 Cable T RB Er E L R oo to loan R TRANS The LINK LED lights indicating that the cable is connected The ERROR LED should remain off indicating that the GPIB extender is working properly 6 Ifthe ERROR LED does not remain off complete the following steps to solve the problem a Verify that the fiber optic cable is connected to the GPIB extender as described in steps 4 and 5 If the problem persists continue to the next step b Repeat steps 4 and 5 using the unconnected ends of the fiber optic cable If switching the fiber optic cable connectors solves the problem you need to replace your fiber optic cable To order a new fiber optic cable contact National Instruments If switching the fiber optic cable connectors does not solve the problem continue to the next step c Ifpossible repeat steps 4 and 5 using a different fiber optic cable If the problem persists you might need to replace your GPIB extender For more information contact National Instruments National Instruments 2 3 Configuring and Using Your Hardware This chapter describes how to configure and use your GPIB 140A or GPIB 140A 2 system Data Transfer Modes The GPIB extender has two data transfer modes unbuffered mode and buffered mode The data transfer mode determines how data is transmitted across the extension Selecting a Data Transfer Mode To select a data transfer mode refer to the following descriptions of each mode Unbuffe
14. 2 Connect the Cables Step 3 Switch On Your GPIB Extender Step 4 Verify the Connection i Chapter 3 Configuring and Using Your Hardware Data Transfer Modes caiano ire iaalione salici diahio Selecting a Data Transfer Mode Unbuffered Mode Buffered Modesa cireni lio eroe Setting the Data Transfer Mode HS488 Mode n Selecting an HS488 Mode HS488 Disabled HS488 Enabledt xi gi ie a AR tl ete a Settine the HS488 Mode s oniinanio e ille e inonda Parallel Poll Response Modes Immediate PPR Mod n tall laici E Eer ESSEE eate Latehe d PPR Modem nnana ILL A EA Selecting a PPR Mode Setting the PPR Mode Using Your Extension System National Instruments vii Contents Chapter 4 Theory of Operation Message Interpreter Layer iiss ate hannah plurale 4 2 Packet Translation Layer Link Management Layer Parallel to Serial Conversion Layer ii 4 2 Physical ayers i i I II enti 4 2 Appendix A GPIB Basics Appendix B Introduction to HS488 Appendix C Multiline Interface Messages Appendix D Specifications Appendix E Technical Support and Professional Services Glossary viii ni com About This Manual This manual describes how to install configure and operate the National Instruments GPIB 140A or GPIB 140A 2 bus extender Conventions The following conventions appear
15. 2 bus extenders comply with the specifications of the ANSI IEEE Standard 488 1 1987 and the ANSI IEEE Standard 488 2 1992 including the Find Listeners protocol With the GPIB extenders you can overcome the following two configuration restrictions imposed by IEEE 488 e A cable length limit of 20 m total per contiguous bus or 2 m per each device on the bus whichever is smaller e Anelectrical loading limit of 15 devices per contiguous bus Each GPIB 140A system extends the GPIB to a maximum distance of 1 km and each GPIB 140A 2 system extends the GPIB to a maximum distance of 2 km Both systems extend the loading limit to 28 devices including the GPIB extenders without sacrificing speed or performance You can connect these point to point extension systems in series for longer distances or in star patterns for additional loading Using the HS488 protocol the maximum data transfer rate over the extension is greater than 2 8 Mbytes s The GPIB extenders use a buffered transfer technique with a serial extension bus which maximizes performance and minimizes the cabling cost Furthermore the extender does not affect the transfer rate between devices on the same side of the extension The GPIB extender can also check for errors to make sure that the data transmitted successfully over the fiber optic link Because the GPIB 140A and GPIB 140A 2 are functionally transparent extenders the GPIB communications and control programs that work with an u
16. 7 DEL Multiline Interface Message Definitions CFE Configuration Enable PPD Parallel Poll Disable CFG Configure PPE Parallel Poll Enable DCL Device Clear PPU Parallel Poll Unconfigure GET Group Execute Trigger SDC Selected Device Clear GTL Go To Local SPD Serial Poll Disable LLO Local Lockout SPE Serial Poll Enable MLA My Listen Address TCT Take Control MSA My Secondary Address UNL Unlisten MTA My Talk Address UNT Untalk PPC Parallel Poll Configure This multiline interface message is a proposed extension to the IEEE 488 specification to support the HS488 protocol National Instruments C 3 Specifications This appendix lists the specifications and characteristics of the GPIB extender System Configuration Distance per extension GPIB 140A ii Up to 1 km GPIB 140A 2 eceeceseeeceeeeteeteeeeneenes Up to 2 km Up to 13 additional devices 28 total devices in the extension system including the extenders Loading per extension Multiple extensions in Permitted in any combination of star or linear pattern Performance Characteristics Maximum transfer rate Buffered mode non HS488 gt 1 1 Mbytes s HS488 handshake gt 2 8 Mbytes s Unbuffered mode eee gt 200 kbytes s Functionality Transparent GPIB operation except for latched parallel polls Interlocked IEEE 488 handshak
17. A 250V 220 240 VAC T 0 3A 350V Environmental Characteristics Operating temperature ees 0 to 40 C Storage temperature ii 20 to 70 C Relative humidity ie 10 to 90 noncondensing D 2 ni com GPIB 140A User Manual Environmental Specifications Pollution Degree Indoor use only Physical Characteristics Overall case size dimensions Case material Weight alal GPIB cable Transmission cable GPIB 140A GPIB 140A 2 5s ini eE A Caution Clean the hardware with hardware is completely dry and free FCC Class A Verified 2 000 m 800 mbar at 25 C ambient temperature 2 3 5 x 5 65 x 1 62 in 8 89 x 14 35 x 4 11 cm All metal enclosure 0 55 Ib 0 25 kg Type X2 shielded 3 0 x 6 5 mm cable diameter 62 5 125 micron core clad with NA 0 275 850 nm operating wavelength 3 0 dB km attenuation Duplex style terminated with ST style connectors 3 0 x 6 5 mm cable diameter 62 5 125 micron core clad with NA 0 275 1300 nm operating wavelength 1 dB km attenuation Duplex style terminated with ST style connectors a soft nonmetallic brush Make sure that the from contaminants before returning it to service To meet FCC emission limits for this device you must use a shielded GPIB cable If you operate this equipment with a non shielded cable it may interfere with radio and television recept
18. E 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 Electromagnetic Compatibility Information This hardware has been tested and found to comply with the applicable regulatory requirements and limits for electromagnetic compatibility EMC as indicated in the hardware s Declaration of Conformity DoC These requirements and limits are
19. GPIB GPIB 140A User Manual February 2013 lt 7 NATIONAL 373124B 01 N INSTRUMENTS Worldwide Technical Support and Product Information ni com Worldwide Offices Visit ni com niglobal to access the branch office Web sites which provide up to date contact information support phone numbers email addresses and current events National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 683 0100 For further support information refer to the Technical Support and Professional Services appendix To comment on National Instruments documentation refer to the National Instruments Web site at ni com info and enter the Info Code feedback 1999 2013 National Instruments All rights reserved Important Information Warranty The GPIB 140A and GPIB 140A 2 are warranted against defects in materials and workmanship for a period 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 repai
20. MER 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 accident 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 National Instruments respects the intellectual property of others and we ask our users to do the same NI software is protected by copyright and other intellectual property law
21. devices in a linear configuration a star configuration or a combination of the two configurations Figure A 2 shows the linear and star configurations Figure A 1 GPIB Connector and the Signal Assignment DIO1 DIO2 DIO3 DIO4 EOI DAV NRFD NDAC IFC SRQ ATN SHIELD A 4 ni com IN Jan s jojnv DIO5 DIO6 DIO7 DIO8 REN GND TW PAIR W DAV GND TW PAIR W NRFD GND TW PAIR W NDAC GND TW PAIR W IFC GND TW PAIR W SRQ GND TW PAIR W ATN SIGNAL GROUND GPIB 140A User Manual Figure A 2 Linear and Star System Configuration NU Sia Device A 5 Device A Device D Device B Device C Device B Device C a Linear Configuration b Star Configuration The standard connector is the Amphenol or Cinch Series 57 Microribbon or Amp Champ type For special interconnection applications you use an adapter cable using a non standard cable and or connector The GPIB uses negative logic with standard TTL transistor transistor logic level For example when DAV is true it is a TTL low level lt 0 8 V and when DAV is false it is a TTL high level gt 2 0 V Configuration Requirements To achieve the high data transfer rate that the GPIB was designed for you must limit the number of devices on the bus and the physical distance between
22. e Maintained across the extension in unbuffered mode IEEE 488 capability identification codes Complete Source Handshake Complete Acceptor Handshake Complete Talker Complete Listener Complete Service Request Complete Remote Local Complete Parallel Poll Complete Device Clear Complete Device Trigger Complete Controller Tri state GPIB driver HS488 Source Handshake HS488 Acceptor Handshake National Instruments D 1 Appendix D Specifications Operational Characteristics Architecture ieai E EE ii Point to point not multi drop transmission Operating Modes c ensscrsieveteetsede dusgiLa Buffered or unbuffered interlocked mode HS488 modes Enabled HS488 or disabled HS488 mode Immediate Parallel Poll Response mode or latched Parallel Poll Response mode Parallel Poll Response modes Electrical Characteristics Transmission interface unit GPIB 140A lara Optical transmitter and receiver HFBR1414 HFBR2416 or equivalent with ST style optical cable connectors GPIB 140A72t IE ILLE Optical transmitter and receiver HFBR1312 HFBR1316 or equivalent with ST style optical cable connectors GPIB interface load Two standard loads AC and DC Power supply unit 100 120 VAC 50 60 Hz 220 240 VAC 50 60 Hz Maximum current requirement 100 120 VAC iii 135 mA 220 240 VAC lie 100 mA Fuse rating and type 100 120 VAC lie T 0 5
23. ensorDAQ and Vernier are registered trademarks of Vernier Software amp Technology Vernier Software amp Technology and vernier com are trademarks or trade dress Xilinx is the registered trademark of Xilinx Inc Taptite and Trilobular are registered trademarks of Research Engineering amp Manufacturing Inc FireWire is the registered trademark of Apple Inc Linux is the registered trademark of Linus Torvalds in the U S and other countries Handle Graphics MATLAB Real Time Workshop Simulink Stateflow and xPC TargetBox are registered trademarks and TargetBox and Target Language Compiler are trademarks of The MathWorks Inc Tektronix Tek and Tektronix Enabling Technology are registered trademarks of Tektronix Inc The Bluetooth word mark is a registered trademark owned by the Bluetooth SIG Inc The ExpressCard word mark and logos are owned by PCMCIA and any use of such marks by National Instruments is under license The mark LabWindows is used under a license from Microsoft Corporation Windows is a registered trademark of Microsoft Corporation in the United States and other countries Other product and company names mentioned herein are trademarks or trade names of their respective companies Members of the National Instruments Alliance Partner Program are business entities independent from National Instruments and have no agency partnership or joint venture relationship with National Instrumen
24. ents and controllers from various vendors It contains information about electrical mechanical and functional specifications GPIB is a digital 8 bit parallel communications interface with data transfer rates of 1 Mbyte s and higher using a three wire handshake The bus supports one System Controller usually a computer and up to 14 additional instruments The ANSI IEEE Standard 488 2 1992 extends IEEE 488 1 by defining a bus communication protocol a common set of data codes and formats and a generic set of common device commands Types of Messages Interconnected GPIB devices communicate by passing messages through the interface system including device dependent messages and interface messages e Device dependent messages also called data or data messages contain device specific information such as programming instructions measurement results machine status and data files e Interface messages also called commands or command messages manage the bus itself Interface messages initialize the bus address and unaddress devices and set device modes for remote or local programming The term command as used here does not refer to device instructions which are also called commands Those device specific instructions are data messages Talkers Listeners and Controllers GPIB devices can be Talkers Listeners or Controllers A Talker sends out data messages Listeners receive data messages The Controller usually a computer
25. er Transfer Rates HS488 enables transfer rates that are substantially faster than the IEEE 488 standard In small systems the raw transfer rate can be up to 8 Mbytes s The faster raw transfer rates improve system throughput in systems where devices send long blocks of data The physical limitations of the cabling system however limit the transfer rate Compatibility with IEEE 488 Devices HS488 is a superset of the IEEE 488 standard thus you can mix IEEE 488 1 IEEE 488 2 and HS488 devices in the same system When connected to an HS488 device the Controller does not need to be capable of HS488 noninterlocked transfers While ATN is asserted the Controller sources multiline messages to HS488 devices just as it sources multiline messages to any IEEE 488 devices Automatic HS488 Detection Addressed HS488 devices can detect whether other addressed devices are capable of HS488 transfers without the interaction of the Controller Compatibility with the IEEE 488 2 Standard The HS488 protocol requires no changes to the IEEE 488 2 standard Also HS488 devices do not need to be compliant with IEEE 488 2 National Instruments B 1 Appendix B Introduction to HS488 Same Cabling Restrictions as IEEE 488 1 Systems that meet the IEEE 488 1 requirements for high speed operation also meet the HS488 requirements HS488 cabling requirements are also the same as the requirements in the IEEE 488 1 standard However using HS488 does not
26. for data Listening device is ready not ready to receive a message byte Also used by the Talker to signal high speed GPIB transfers NDAC not data accepted Listening device has has not accepted a message byte DAV data valid Talking device indicates signals on data lines are stable valid data Interface Management Lines Five hardware lines manage the flow of information across the bus Table A 2 summarizes the GPIB interface management lines Table A 2 GPIB Interface Management Lines Line Description ATN Controller drives ATN true when it sends commands and false when it attention sends data messages IFC System Controller drives the IFC line to initialize the bus and make itself interface clear CIC REN System Controller drives the REN line to place devices in remote or remote enable local program mode SRQ Any device can drive the SRQ line to asynchronously request service service request from the Controller EOI Talker uses the EOI line to mark the end of a data message Controller end or identify uses the EOI line when it conducts a parallel poll National Instruments A 3 Appendix A GPIB Basics Physical and Electrical Characteristics Devices are usually connected with a cable assembly consisting of a shielded 24 conductor cable with both a plug and receptacle connector at each end as shown in Figure A 1 With this design you can link
27. he Latched PPR Mode section later in this chapter Immediate PPR Mode In immediate PPR mode the GPIB extenders do not use the internal PPR data register When a Controller on the local system asserts IDY the local extender sends the IDY message to the remote bus and the response is returned as fast as propagation delays permit Your application must allow enough time to receive the response Latched PPR Mode In latched PPR mode the GPIB extenders use an internal PPR data register When a Controller on the local system asserts IDY the local extender sends the contents of the PPR data register to the local data lines At the same time a parallel poll message is sent to the remote bus When the local system unasserts IDY the PPR from the remote system is loaded into the internal PPR data register Consequently the register always contains the response of the previous complete poll To obtain the response of both local and remote systems your application should execute two consecutive parallel polls and use the second response National Instruments 3 3 Chapter 3 Configuring and Using Your Hardware The software driver library of most Controllers contains an easy to use parallel poll function For example if the function is called ibrpp and your application is written in BASIC the sequence to execute a poll in latched PPR mode might be similar to the following sequence CALL ibrpp brd0 ppr CALL ibrpp brd0 ppr IF ppr gt
28. he PPR Mode To use immediate PPR mode set DIP switch 3 to the ON position as shown in Figure 3 3 To use latched PPR mode set DIP switch 3 to the OFF position Figure 3 3 DIP Switch Setting for Immediate PPR Mode l Not used to set Parallel Poll Response PPR mode OFF PARALLEL POLL IMMEDIATE HS488 ENABLE BUFFERED TRANSFER 3 4 ni com GPIB 140A User Manual Using Your Extension System After you supply power to both extenders and connect the fiber optic cable you can use your GPIB 140A or GPIB 140A 2 extension system Table 3 1 lists the three LEDs that indicate the operational status of each GPIB extender Table 3 1 GPIB 140A LEDs LED Description POWER Lights if power is supplied to the GPIB extender and the power switch is in the on position LINK Lights if both GPIB extenders are powered on and the transmission cable is properly connected to both extenders During operation the LINK LED turns off if you disconnect the cable from the receiver of the GPIB extender or if you power off either GPIB extender ERROR Lights if the GPIB extender receives corrupted data The ERROR LED turns off after the GPIB extender starts re transmission and has received the first retransmitted data byte without error National Instruments 3 5 Theory of Operation This chapter describes how the GPIB extender circuitry operates This chapter assumes that you are famil
29. iar with GPIB If you are a first time user or if you would like to review the basics about GPIB refer to Appendix A GPIB Basics Figure 4 1 shows the five layers of a GPIB extender To form a complete link you can connect each layer to the corresponding layer of another extender at the remote side Figure 4 1 GPIB Extender Block Diagram gt Message Interpreter GPIB EXTENDER Layer Packet Translation Layer Link Management Layer Parallel to Serial Conversion Layer Physical Layer A GPIB BUS 1 Transmission GPIB BUS 2 Medin y Parallel to Serial Conversion Layer Physical Layer Link Management Layer Packet Translation Layer Message Interpreter Layer GPIB EXTENDER National Instruments 44 Chapter 4 Theory of Operation Message Interpreter Layer The Message Interpreter Layer handles the handshake between the GPIB extender and other devices on the GPIB At the same time the layer monitors the activities that occur on the GPIB translates them into equivalent local and remote GPIB messages and sends these messages to the Packet Translation Layer Packet Translation Layer The Packet Translation Layer converts the messages that it receives to packets and sends them to the Link Management Layer It can also receive packets from the Link Manage
30. ications and the DoC for this product visit ni com certification search by model number or product line and click the appropriate link in the Certification column D 4 ni com GPIB 140A User Manual Environmental Management NI is committed to designing and manufacturing products in an environmentally responsible manner NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers For additional environmental information refer to the Minimize Our Environmental Impact web page at ni com environment This page contains the environmental regulations and directives with which NI complies as well as other environmental information not included in this document Waste Electrical and Electronic Equipment WEEE x EU Customers At the end of the product life cycle all products must be sent to a WEEE recycling center For more information about WEEE recycling centers National Instruments WEEE initiatives and compliance with WEEE Directive 2002 96 EC on Waste and Electronic Equipment visit ni com environment weee EFAA mis Riehl BEDE CE ROHS OO PERA National Instruments R amp B ETAR A IE SE HR ROHS XF National Instruments El ROHS AREA Ex ni com environment rohs_china For information about China ROHS compliance go to ni com environment rohs_china National Instruments D 5 Technical Support and Professional Service
31. ices or contact your local office at ni com contact e Training and Certification Visit ni com training for training and certification program information You can also register for instructor led hands on courses at locations around the world e System Integration Ifyou have time constraints limited in house technical resources or other project challenges National Instruments Alliance Partner members can help To learn more call your local NI office or visit ni com alliance You also can visit the Worldwide Offices section of ni com niglobal to access the branch office Web sites which provide up to date contact information support phone numbers email addresses and current events National Instruments E 1 Glossary Symbol Prefix Value p pico 10 2 n nano 10 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 T tera 10 2 Symbols is degrees percent A A amperes AC alternating current AHE HS488 Acceptor Handshake Extended interface function ANSI American National Standards Institute ASCII American Standards Code for Information Interchange ASIC application specific integrated circuit ATN Attention National Instruments G 1 Glossary C c CIC CPU CSA DAV DC DIO DIP EOI EOS FCC FIFO G2 ni com Celsius Controller In Charge central processing unit Canadian Standards Association data valid decibel
32. ion National Instruments D 3 Appendix D Specifications Safety This product is designed to meet the requirements of the following standards of safety for information technology equipment e IEC 60950 1 EN 60950 1 e UL 60950 1 CSA 60950 1 A Caution The protection provided by the GPIB 140A can be impaired if it is used in a manner not described in this document Note For UL and other safety certifications refer to the product label or the Online Product Certification section Electromagnetic Compatibility This product meets the requirements of the following EMC standards for electrical equipment for measurement control and laboratory use e EN 61326 IEC 61326 Class A emissions Basic immunity e EN 55011 CISPR 11 Group 1 Class A emissions e AS NZS CISPR 11 Group 1 Class A emissions e FCC 47 CFR Part 15B Class A emissions e ICES 001 Class A emissions Note For the standards applied to assess the EMC of this product refer to the Online Product Certification section Note For EMC compliance operate this device with shielded cabling CE Compliance CE This product meets the essential requirements of applicable European Directives as follows e 2006 95 EC Low Voltage Directive safety e 2004 108 EC Electromagnetic Compatibility Directive EMC Online Product Certification Refer to the product Declaration of Conformity DoC for additional regulatory compliance information To obtain product certif
33. ions If you need to change these settings refer to Chapter 3 Configuring and Using Your Hardware for instructions on how to set the operation mode for your application National Instruments 2 1 Chapter 2 Connecting Your Hardware Step 2 Connect the Cables To connect the cables to both GPIB extenders complete the following steps 1 Make sure that each GPIB extender is powered off 2 Connect the two connectors on each end of the fiber optic cable to your GPIB extenders as follows a As shown in Figure 2 2 align the connector marked T transmit with the connector marked TRANS on the side panel of the GPIB extender Align the connector marked R receive with the connector marked RCVR on the side panel of the GPIB extender Figure 2 2 Connecting the Fiber Optic Cable to Both GPIB Extenders GPIB 140A or GPIB 140A or GPIB 140A 2 GPIB 140A 2 b Remove the caps on the connectors c Align the notch on each cable connector to the slot of the fiber optic connector on the box d Firmly push in the cable connector and rotate the sleeve clockwise until it locks on to the side notch of the fiber optic connector on the box 3 Connect the end of the extender with the GPIB connector to your GPIB system Make sure that you follow all IEEE 488 cabling restrictions For typical restrictions refer to the Configuration Requirements section in Appendix A GPIB Basics 4 Plug the utilit
34. ire Transfers DIO18 composite X X X DAV NFRD of Se DEI ope LS NDAC Figure B 2 shows an HS488 data transfer The HS488 protocol modifies the IEEE 488 1 SH and AH functions At the beginning of each data transfer the HS488 SHE and AHE functions determine whether all active Talkers and Listeners are capable of HS488 transfers If the addressed devices are HS488 capable they use the HS488 noninterlocked handshake protocol for that data transfer If any addressed device is not HS488 capable the transfer continues using the standard three wire handshake Figure B 2 HS488 Transfers HS488 Transfers igomposte DX X X X X DAV NFRD NDAC National Instruments B 3 Appendix B Introduction to HS488 Case 1 Talker and Listener Are HS488 Capable Figure B 3 and the following steps describe a typical sequence of events in an HS488 data transfer in which both the Talker and Listener are HS488 capable Figure B 3 HS488 Capable Talker and Listener First byte transferred using 488 1 handshake ATN TI T13 T14 lt composite DAV y NFRD NDAC t i Second byte transferred using high speed mode The sending device uses this high speed capable signal the momentary low going pulse on NRFD to tell the receiving device that
35. ment Layer and convert them back to local or remote GPIB messages Link Management Layer The Link Management Layer receives packets from the Packet Translation Layer It sends the packets to the Parallel to Serial Conversion Layer and it stores them in a local buffer If a transmission error occurs the Link Management Layer can re send the packets from this local buffer The Link Management Layer also receives packets from the Parallel to Serial Conversion Layer and checks the packets for transmission errors If the Link Management Layer does not detect an error it sends the packets to the Packet Translation Layer However if it detects a transmission error the it re transmits the packets Parallel to Serial Conversion Layer The Parallel to Serial Conversion Layer accepts packets from the Link Management Layer converts them into serial data and sends the data to the Physical Layer It also extracts serial bits from the Physical Layer reconstructs them back into packets and sends them to the Link Management Layer Physical Layer The Physical Layer transmits and receives serial data over the fiber optic link 4 2 ni com GPIB Basics This appendix describes the basic concepts of GPIB including its physical and electrical characteristics and configuration requirements The ANSI IEEE Standard 488 1 1987 also known as General Purpose Interface Bus GPIB describes a standard interface for communication between instrum
36. ne Interface Messages Hex Dec ASCII Message Hex Dec ASCII Message 00 0 NUL 20 32 SP MLAO 01 1 SOH GTL 21 33 MLA1 02 2 STX 22 34 MLA2 03 3 ETX 23 39 MLA3 04 4 EOT SDC 24 36 MLA4 05 5 ENQ PPC 25 37 MLAS 06 6 ACK 26 38 amp MLA6 07 7 BEL 27 39 MLA7 08 8 BS GET 28 40 MLA8 09 9 HT TCT 29 41 MLA9 0A 10 LF 2A 42 MLA10 0B 11 VT 2B 43 MLA11 0c 12 FF 2C 44 MLA12 0D 13 CR 2D 45 MLA13 0E 14 SO 2E 46 MLA14 OF 15 SI 2F 47 MLA15 10 16 DLE 30 48 0 MLA16 11 17 DCI LLO 31 49 1 MLA17 12 18 DC2 32 50 2 MLA18 13 19 DC3 33 S1 3 MLA19 National Instruments C 1 Appendix C Multiline Interface Messages Table C 1 Multiline Interface Messages Continued Hex Dec ASCII Message Hex Dec ASCII Message 14 20 DC4 DCL 34 52 4 MLA20 15 21 NAK PPU 35 53 5 MLA21 16 22 SYN 36 54 6 MLA22 17 23 ETB 37 55 7 MLA23 18 24 CAN SPE 38 56 8 MLA24 19 25 EM SPD 39 57 9 MLA25 1A 26 SUB 3A 58 MLA26 1B 27 ESC 3B 59 MLA27 1C 28 FS 3C 60 lt MLA28 1D 29 GS 3D 61 MLA29 1E 30 RS 3E 62 gt
37. nextended system also work with an extended system However the Parallel Poll Response Modes section in Chapter 3 Configuring and Using Your Hardware describes one exception to this transparency in conducting parallel polls Time Saving Development Tools Your kit includes the GPIB 140A or GPIB 140A 2 bus extender In addition you can order the NI 488 2 LabWindows CVI or LabVIEW software from National Instruments to speed your application development time and make it easier to communicate with your instruments The NI 488 2 software supports the concurrent use of multiple types of GPIB hardware For example you can communicate with GPIB devices through a PCI GPIB a PCMCIA GPIB and a GPIB ENET 100 in the same system at the same time The NI 488 2 software along with the GPIB hardware transforms your computer into a GPIB Talker Listener Controller with complete communications and bus management capability 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 c
38. om GPIB 140A User Manual Case 2 Talker Is HS488 Capable But Listener Is Not HS488 Capable Figure B 4 and the following steps describe a typical sequence of events in an HS488 data transfer in which the Talker is HS488 capable but the Listener is not Figure B 4 HS488 Capable Talker ATN DIO18 composite TI DAV NFRD n i NDAC High speed capable signal Low going transition on NRFD indicates that not all receiving devices are high speed capable Steps 1 6 are identical to steps 1 6 in Case 1 Talker and Listener Are HS488 Capable The Listener ignores the HSC message from the Talker Then the IEEE 488 1 Listener enters ACDS and asserts NRFD As a result the Talker determines that the addressed Listener is not HS488 capable The Talker sources bytes using the IEEE 488 1 protocol National Instruments B 5 Appendix B Introduction to HS488 Case 3 Talker Is Not HS488 Capable But Listener Is HS488 Capable The Talker does not send an HSC message to the Listener but sources bytes using the IEEE 488 1 protocol The addressed Listener HS488 or IEEE 488 1 accepts bytes using the IEEE 488 1 standard three wire handshake as shown in Figure B S Figure B 5 Listener ls HS488 Capable ATN TI DIO18 composite OOOO DDD O DAV NFRD NDAC System Configuration The HS488 AHE and SHE interface f
39. ontrol of each instrument National Instruments 1 3 Chapter 1 Introduction LabWindows CVI is similar to Lab VIEW except that it combines an interactive easy to use development approach with the programming power and flexibility of compiled ANSI C code The GPIB Analyzer is another optional tool available from National Instruments that is useful in troubleshooting a variety of IEEE 488 hardware and software problems With its built in time stamping capability you can easily determine the throughput and overhead of your GPIB systems The GPIB Analyzer software for Windows works with the AT GPIB TNT PCI GPIB and NI PCIe GPIB products which provide GPIB Analyzer support along with the functionality of a high performance GPIB Controller For ordering information or to request free demonstration software contact National Instruments 1 4 ni com Connecting Your Hardware This chapter describes how to connect your GPIB extender and verify that it is working properly Step 1 Verify the DIP Switch Setting The 3 bit DIP switch sets the operation mode of the GPIB extender The default switch setting is for unbuffered transfer mode latched parallel poll response PPR and HS488 disabled mode as shown in Figure 2 1 Figure 2 1 Default DIP Switch Setting OFF PARALLEL POLL IMMEDIATE HS488 ENABLE BUFFERED TRANSFER Verify that the DIP switches on your GPIB extender are in these default posit
40. r 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 edition 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 CUSTO
41. red Mode In unbuffered mode each data byte is transmitted using the GPIB double interlocked handshaking protocol For long data streams transfers are slower than transfers using buffered mode However the GPIB extension is transparent in unbuffered mode Buffered Mode In buffered mode the GPIB extenders use FIFO first in first out buffers to buffer data between the remote and local units For long data streams the data throughput is much higher than with unbuffered mode However a few applications may not operate properly in buffered mode For example a GPIB device on the local side of the extension is addressed to talk another device on the remote side is addressed to listen When the Talker sources data bytes the GPIB extenders accept the data bytes and store them in a FIFO buffer At the same time the GPIB extenders read data from the FIFO buffer and source data bytes to the Listener If the FIFO buffer contains data the number of bytes sourced by the Talker differs from the number of bytes accepted by the Listener GPIB command bytes are not stored in the FIFO buffers they are transmitted using the GPIB double interlocked handshaking protocol National Instruments 3 1 Chapter 3 Configuring and Using Your Hardware Setting the Data Transfer Mode The two GPIB extenders in your extension system must use the same data transfer mode To use buffered mode set DIP switch 1 to the ON position as shown in Figure 3 1 To use
42. s Log in to your National Instruments ni com User Profile to get personalized access to your services Visit the following sections of ni com for technical support and professional services e Support Technical support at ni com support includes the following resources Self Help Technical Resources For answers and solutions visit ni com support for software drivers and updates a searchable KnowledgeBase product manuals step by step troubleshooting wizards thousands of example programs tutorials application notes instrument drivers and so on Registered users also receive access to the NI Discussion Forums at ni com forums NI Applications Engineers make sure every question submitted online receives an answer Standard Service Program Membership This program entitles members to direct access to NI Applications Engineers via phone and email for one to one technical support as well as exclusive access to self paced online training modules at ni com self paced training All customers automatically receive a one year membership in the Standard Service Program SSP with the purchase of most software products and bundles including NI Developer Suite NI also offers flexible extended contract options that guarantee your SSP benefits are available without interruption for as long as you need them Visit ni com ssp for more information For information about other technical support options in your area visit ni com serv
43. s direct current digital input output dual inline package End or Identify End of String Farads Federal Communications Commission first in first out GPIB IDY IEC IEEE IFC SHE GPIB 140A User Manual grams General Purpose Interface Bus hexadecimal hertz Identify International Electrotechnical Commission Institute of Electrical and Electronic Engineers Interface Clear inches pounds light emitting diode meters seconds HS488 Source Handshake Extended interface function National Instruments G 3 Glossary T TTL transistor transistor logic UL Underwriter s Laboratories V volts VAC volts alternating current G 4 ni com
44. s Where NI software may be used to reproduce software or other materials belonging to others you may use NI software only to reproduce materials that you may reproduce in accordance with the terms of any applicable license or other legal restriction End User License Agreements and Third Party Legal Notices You can find end user license agreements EULAs and third party legal notices in the following locations e Notices are located in the lt National Instruments gt _Legal Information and lt National Instruments gt directories e EULAs are located in the lt National Instruments gt Shared MDF Legal license directory e Review lt National Instruments gt _Legal Information txt for more information on including legal information in installers built with NI products Trademarks Refer to the NI Trademarks and Logo Guidelines at ni com trademarks for more information on National Instruments trademarks ARM Keil and Vision are trademarks or registered of ARM Ltd or its subsidiaries LEGO the LEGO logo WEDO and MINDSTORMS are trademarks of the LEGO Group 2013 The LEGO Group TETRIX by Pitsco is a trademark of Pitsco Inc 2013 FIELDBUS FOUNDATION and FOUNDATION are trademarks of the Fieldbus Foundation EtherCAT is a registered trademark of and licensed by Beckhoff Automation GmbH CANopen is a registered Community Trademark of CAN in Automation e V DeviceNet and EtherNet IP are trademarks of ODVA Go S
45. t be changed The Controller function is usually handled by a computer With the GPIB interface board and its software your personal computer plays all three roles e Controller to manage the GPIB e Talker to send data Listener to receive data Controller In Charge and System Controller You can have multiple Controllers on the GPIB but only one Controller at a time can be the active Controller or Controller In Charge CIC The CIC can be either active or inactive standby Control can pass from the current CIC to an idle Controller but only the System Controller usually a GPIB interface can make itself the CIC GPIB Signals and Lines Devices on the bus communicate by sending messages Signals and lines transfer these messages across the GPIB interface which consists of 16 signal lines and 8 ground return shield drain lines The 16 signal lines are discussed in the following sections Data Lines Eight data lines DIO1 through DIO8 carry both data and command messages A 2 ni com GPIB 140A User Manual Handshake Lines Three hardware handshake lines asynchronously control the transfer of message bytes between devices This process is a three wire interlocked handshake and it guarantees that devices send and receive message bytes on the data lines without transmission error Table A 1 summarizes the GPIB handshake lines Table A 1 GPIB Handshake Lines Line Description NRFD not ready
46. ts Patents For patents covering National Instruments products technology refer to the appropriate location Help Patents in your software the patents txt file on your media or the National Instruments Patent Notice at ni com patents Export Compliance Information Refer to the Export Compliance Information at ni com legal export compliance for the National Instruments global trade compliance policy and how to obtain relevant HTS codes ECCNs and other import export data 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 CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF TH
47. unbuffered mode set DIP switch 1 to the OFF position Figure 3 1 DIP Switch Setting for Buffered Mode Not used to set data transfer mode PARALLEL POLL IMMEDIATE HS488 ENABLE BUFFERED TRANSFER HS488 Mode The GPIB extender can handle data transfers using the HS488 protocol HS488 transfers data between two or more devices using a noninterlocked handshaking protocol You can use HS488 to transfer data at rates higher than rates possible using the IEEE 488 protocol For more information about HS488 refer to Appendix B Introduction to HS488 Selecting an HS488 Mode To select an HS488 mode refer to the following descriptions of each mode HS488 Disabled If you disable HS488 the GPIB extender sources and accepts data using a three wire handshaking protocol even if both the Talker and Listener can transfer data using the HS488 protocol HS488 Enabled After the Talker indicates that it wants to issue HS488 transfers HS488 is enabled and the GPIB extender accepts data using the HS488 protocol Also when talking the GPIB extender always tries to use the HS488 mode In HS488 mode FIFO buffers buffer data during HS488 transfers even if the data transfer mode is set to unbuffered When you use the HS488 protocol with the GPIB extender you should set the GPIB cable length to 5 m for both the local and the remote system To do so use your IEEE 488 2 software configuration utility Setting the HS488 Mode
48. unctions depend on several time delays Some of these delays are a function of the total system cable length The Controller must communicate this system configuration data to HS488 devices after the system powers on The Controller configures HS488 devices by sourcing the following two multiline messages while ATN is true e Configuration Enable CFE The Controller sends the CFE message by driving a bit pattern 1E hex that the IEEE 488 1 standard does not define on the DIO signal lines The CFE message enables HS488 devices to interpret the SCG message that follows e Secondary Command Group SCG This message contains the configuration data The Secondary Command has the bit pattern 6n hex where n is the meters of cable in the system The SCG includes CFG1 CFG15 in Appendix C Multiline Interface Messages B 6 ni com Multiline Interface Messages This appendix lists the multiline interface messages and describes the mnemonics and messages that correspond to the interface functions The multiline interface messages are commands defined by the IEEE 488 standard The messages are sent and received with ATN asserted The interface functions include initializing the bus addressing and unaddressing devices and setting device modes for local or remote programming For more information about these messages refer to the ANSI IEEE Standard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation Table C 1 Multili
49. y power cord included with your GPIB extender into an AC outlet of the correct voltage 5 Plug the other end of the utility power cord into your GPIB extender Step 3 Switch On Your GPIB Extender Power on each GPIB extender The POWER LED should light immediately If the POWER LED does not light immediately make sure that power is supplied to your GPIB extender The LINK LED lights only when both GPIB extenders are on and the fiber optic cable is properly connected between them 2 2 ni com GPIB 140A User Manual Step 4 Verify the Connection Each GPIB extender has a self test that determines whether the GPIB extender receivers transmitters and packet transmission and reception circuitry are working properly To run the self test complete the following steps 1 Power off the GPIB extender 2 Disconnect the fiber optic cable from the GPIB extender 3 Power on the GPIB extender The POWER LED lights indicating that power is supplied to the extender The LINK LED remains off 4 Connect the connector marked T transmit on one end of the fiber optic cable to the connector marked TRANS on the side panel of the GPIB extender 5 Connect the connector marked R receive on the opposite end of the fiber optic cable to the connector marked RCVR on the side panel of the GPIB extender Figure 2 3 GPIB Extender Self Test Configuration GPIB 140A or Fiber Optic RCVR GPIB 140A
Download Pdf Manuals
Related Search