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National Instruments GPIB

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1. Communications This device complies with the limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications DOC Le pr sent appareil num rique n met pas de bruits radio lectriques d passant les limites applicables aux appareils num riques de classe A prescrites dans le r glement sur le brouillage radio lectrique dict par le minist re des communications du Canada Instructions to Users These regulations are designed to provide reasonable protection against harmful interference from the equipment to radio reception in commercial areas 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 There is no guarantee that interference will not occur in a particular installation However the chances of interference are much less if the equipment is installed and used according to this instruction manual If the equipment does cause interference to radio or television reception which can be determined by turning the equipment on and off one or more of the following suggestions may reduce or eliminate the problem e Operate the equipment and the receiver on different branches of your AC electrical system e Move the equipment away from the receiver with which it is interfering e Reorient or relocate the receiver s ante
2. Switches 4 through 8 Continued Switches 4 5 6 7 8 Indication ON ON OFF ON OFF ON ON ON OFF ON Step 4 Connect the Cables Connect the cables as follows 1 Connect the power jack of the wall mount power supply to the power receptacle on the back panel of the GPIB BUF then plug the supply into an AC outlet of the correct voltage 2 Connect a GPIB cable from the target device to the GPIB OUT port on the rear panel of the GPIB BUF 3 Connect another GPIB cable from the GPIB IN port on the rear panel of the GPIB BUF to the remaining GPIB devices in your system Note In steps 2 and 3 be sure to obey all IEEE 488 cabling restrictions and tighten all lock screws on the GPIB connectors GPIB BUF User Manual 2 6 National Instruments Corp Chapter 2 Installation and Operation Step 5 Power on the Unit Power on your target device then power on your GPIB BUF by using the front panel rocker switch The POWER LED should light immediately and the READY indicator should blink while the unit executes its power on self test The READY indicator should stop blinking and remain on when the GPIB BUF has passed its power on self test indicating the unit is ready for operation If the READY indicator does not start to blink immediately or continues to blink for more than 7 s for the 256 KB model or 20 s for the 1 MB model after the unit is powered on recheck all connections and switch settings and retry the power on sequence
3. failure or by errors on the part of the user or application designer Any use or application of National Instruments products for or involving medical or clinical treatment must be performed by properly trained and qualified medical personnel and all traditional medical safeguards equipment and procedures that are appropriate in the particular situation to prevent serious injury or death should always continue to be used when National Instruments products are being used National Instruments products are NOT intended to be a substitute for any form of established process procedure or equipment used to monitor or safeguard human health and safety in medical or clinical treatment FCC DOC Radio Frequency Interference Compliance This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the instructions in this manual may cause interference to radio and television reception This equipment has been tested and found to comply with the following two regulatory agencies Federal Communications Commission This device complies with Part 15 of the Federal Communications Commission FCC Rules for a Class A digital device Operation is subject to the following two conditions 1 This device may not cause harmful interference in commercial environments 2 This device must accept any interference received including interference that may cause undesired operation Canadian Department of
4. in either direction The notations GPIB IN and GPIB OUT are used in order to differentiate the ports since the GPIB IN port under normal circumstances receives data while the GPIB OUT port normally sends data to the GPIB target device GPIB BUF User Manual 1 4 National Instruments Corp Chapter 1 Description of the GPIB BUF The port labeled GPIB IN is intended to be connected to a GPIB system that includes one or more GPIB devices which send data to the GPIB target device All data received via the GPIB IN port is transferred into the Random Access Memory RAM buffer of the GPIB BUF using the on board Direct Memory Access DMA controller The port labeled GPIB OUT should be connected to the GPIB target device This port has GPIB controller capabilities and addresses the GPIB target device when required All data input to the internal GPIB BUF RAM buffer is output via the GPIB OUT port Under normal operating conditions you should only connect one device your GPIB target device to the GPIB OUT port Figure 1 4 shows a diagram of one of the GPIB connectors and the signal designations Only one GPIB connector is shown since both connectors have the same signal and pin descriptions A suffix indicates that the signal is active low DIO1 DIO2 DIO6 DIO3 DIO7 DIO4 DIO8 EOI REN DAV GND Twisted Pair with DAV NRFD GND Twisted Pair with NRFD NDAC GND Twisted Pair with NDAC IFC GND Twisted Pair with IFC SRQ
5. is ready for additional data The Controller can then re address the GPIB BUF to listen and continue sending the rest of the file in the above manner until all the data has been transferred Since the GPIB BUF is a fully transparent self contained unit the amount of data buffering can also be increased by chaining multiple GPIB BUF units together Another means by which a Controller can determine if a device requires service is by a parallel poll During a parallel poll each responding device indicates its need for service by returning a status bit via one of the GPIB data lines GPIB data line assignments as well as the level high or low of the GPIB line depend on the last parallel poll configuration command sent to the device GPIB BUF User Manual 3 6 National Instruments Corp Chapter 3 Technical Information Internally the local Individual Status ist bit of the GPIB BUF is reset to 0 when the internal data buffer is empty of data It is set to 1 when the internal data buffer is not empty Therefore after the GPIB Controller configures the GPIB BUF with a Parallel Poll Enable PPE message from 60 to 67 hex the GPIB BUF during a parallel poll drives the data line which the Controller has specified active when the internal data buffer is empty When data is present in the GPIB BUF it drives the data line inactive Likewise after the GPIB Controller configures the GPIB BUF with a PPE message from 68 to 6F hex the GPIB
6. 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 Trademarks MicroGPIB is a trademark of National Instruments Corporation Product and company names listed are trademarks or trade names of their respective companies Warning Regarding Medical and Clinical Use of National Instruments Products National Instruments products are not designed with components and testing intended to ensure a level of reliability suitable for use in treatment and diagnosis of humans Applications of National Instruments products involving medical or clinical treatment can create a potential for accidental injury caused by product
7. BUF during a parallel poll drives the data line which the Controller has specified active when the internal data buffer is not empty of data When the internal data buffer is empty it drives the data line inactive The possible parallel poll responses from the GPIB BUF are summarized in Table 3 1 Unlike serial polls you can parallel poll the GPIB BUF even when it is in listen only mode Table 3 1 Parallel Poll Responses GPIB Data Line Driven Active in Response to Parallel Poll Buffer Empty Buffer Not Empty National Instruments Corp 3 7 GPIB BUF User Manual Technical Information Chapter 3 Special Note About Timeouts If your current GPIB system relies on a timeout method to ensure a non functioning GPIB device does not hang the bus indefinitely then it may be necessary to adjust or disable the time limit to ensure that the target device has enough time to respond to any requests for information For example suppose that your current code sends a file to a plotter and then prompts the plotter for its current status If the file is large and GPIB timeouts are in effect the file is transferred to the GPIB BUF followed immediately by the plotter prompt At this time the Controller re addresses the GPIB BUF to talk starts its timeout timer and waits for a response Since the GPIB BUF is still spooling the data file to the plotter which has not yet received the prompt the plotter cannot respond until the entire p
8. GND Twisted Pair with SRQ ATN GND Twisted Pair with ATN SHIELD SIGNAL GROUND Figure 1 4 The GPIB Connector and Signal Designations National Instruments Corp 1 5 GPIB BUF User Manual Chapter 2 Installation and Operation This chapter describes the procedures for installing and operating the GPIB BUF Figure 2 1 shows an example of a GPIB BUF connected to a GPIB system This example shows a GPIB BUF placed in a GPIB system with a GPIB Talker Controller such as an IBM PC with a National Instruments GPIB PCII Controller board installed and a slow GPIB data acceptor such as an HP 7475A Color Plotter Notice that the GPIB BUF is placed in line between the existing GPIB system and the GPIB target device GPIB Cable Figure 2 1 GPIB BUF System Setup Example National Instruments Corp 2 1 GPIB BUF User Manual Installation and Operation Chapter 2 Installation Install the GPIB BUF according to the following procedure 1 Inspect the GPIB BUF 2 Verify the voltage requirement 3 Configure the operating parameters 4 Connect the cables 5 Power on the unit These steps are described in more detail in the following subsections Step 1 Inspect the GPIB BUF Before you install the GPIB BUF inspect the shipping container and its contents for damage If damage appears to have been caused in shipment file a claim with the carrier Retain the packing material for possible inspection and o
9. GPIB The GPIB BUF always asserts REN on the GPIB OUT port REN need not be asserted on the GPIB IN port for the GPIB BUF to operate GPIB BUF User Manual 3 4 National Instruments Corp Chapter 3 Technical Information Polling the GPIB BUF The GPIB BUF can return status information to the GPIB Controller through the serial poll response byte as shown in Figure 3 1 This byte contains two bits of information that reflect the current condition of the GPIB BUF data buffer and whether the GPIB BUF is asserting the SRQ signal on the GPIB IN port The serial poll status byte is returned as follows 0 not asserting SRQ 0 buffer is not empty 1 asserting SRQ 1 buffer is empty Figure 3 1 Serial Poll Status Byte The empty bit always reflects the current status of the buffer while the SRQ bit only returns a 1 if the GPIB BUF is asserting the SRQ signal line The GPIB BUF asserts the SRQ signal if the buffer is currently empty and the SRQ on empty function is enabled by Switch 3 of U38 The GPIB BUF unasserts the SRQ signal when the buffer is no longer empty or when the GPIB Controller serial polls the GPIB BUF Although serial polls are usually in response to an SRQ condition the GPIB BUF can be serial polled at any time for any reason Note The GPIB BUF cannot return a serial poll status byte if it is in listen only mode National Instruments Corp 3 5 GPIB BUF User Manual Technical Information Chapte r 3 The G
10. GPIB BUF User Manual February 1994 Edition Part Number 320125 01 Copyright 1989 1994 National Instruments Corporation All Rights Reserved National Instruments Corporate Headquarters 6504 Bridge Point Parkway Austin TX 78730 5039 512 794 0100 Technical support fax 800 328 2203 512 794 5678 Branch Offices Australia 03 879 9422 Austria 0662 435986 Belgium 02 757 00 20 Canada Ontario 519 622 9310 Canada Qu bec 514 694 8521 Denmark 45 76 26 00 Finland 90 527 2321 France 1 48 14 24 24 Germany 089 741 31 30 Italy 02 48301892 Japan 03 3788 1921 Netherlands 03480 33466 Norway 32 848400 Spain 91 640 0085 Sweden 08 730 49 70 Switzerland 056 20 51 51 U K 0635 523545 MicroGPIB Products National Instruments has developed the MicroGPIB product line to offer a series of high performance low cost IEEE 488 support items that are packaged in small all metal cases capable of being rack mounted Limited Warranty The GPIB BUF is warranted against defects in materials and workmanship for a period of two years 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 A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment
11. If the READY light still fails to come on or continues to blink longer than the specified time limits contact National Instruments for further instructions Operation The GPIB BUF is now ready to operate When the GPIB BUF is powered on it asserts the Interface Clear IFC line on the GPIB OUT port to initialize the GPIB link to the target device therefore ensure that the GPIB target device is powered on before the GPIB BUF When the GPIB BUF is addressed to listen all data sent to the unit via the GPIB IN port is input directly to memory by the on board DMA controller at speeds up to 900 kbytes s and is stored in the internal data buffer The actual speed depends on the speed of the GPIB talker as well as the speed of other GPIB devices that are addressed to listen along with the GPIB BUF Thus the speed is no longer limited to the speed of the target device which is now isolated from the rest of the GPIB system The GPIB BUF addresses the target device to listen and sends the buffered data to the target device at the maximum rate that the target device can receive the data When addressed to talk the GPIB BUF waits until it has emptied all the data currently stored in its internal buffer then addresses the target device to talk All data sent by the target device is passed directly through the GPIB BUF to the GPIB listener s on the GPIB system The addressing of the target device as well as the routing and buffering of data is
12. MPTY FULL Figure 1 2 The GPIB BUF Front Panel The LEDs show the current status of the GPIB BUF at all times The following table describes each LED Table 1 1 LED Descriptions POWER Indicates that power to the unit has been applied and the ON OFF switch is in the ON position READY Indicates that the unit is running its power on self test blinking has passed its power on self test and is ready to operate steady on or has failed the power on self test steady off TALK Indicates that the GPIB BUF is configured as a GPIB Talker LISTEN Indicates that the GPIB BUF is configured as a GPIB Listener EMPTY Indicates that the internal data buffer of the GPIB BUF is empty Indicates that the internal buffer of the GPIB BUF is full National Instruments Corp 1 3 GPIB BUF User Manual Description of the GPIB BUF Chapter 1 The GPIB BUF Rear Panel Figure 1 3 shows the power cable and the GPIB cables connected to the rear panel of the GPIB BUF Figure 1 3 The GPIB BUF Rear Panel The GPIB Connectors The GPIB BUF has two GPIB connectors labeled GPIB IN and GPIB OUT Both GPIB connectors are standard 24 pin shielded AMP CHAMP female connectors with metric screwlock hardware As you face the rear panel the GPIB IN connector is the right most GPIB connector The GPIB OUT connector is located on the left Notice that although these GPIB ports are labeled GPIB IN and GPIB OUT both are able to transfer data
13. PIB BUF SRQ on empty feature and serial poll status byte are useful for several reasons e A remote Controller is able to tell when a data transfer to a plotter or printer is completely finished e A ready indicator is provided to a remote GPIB Controller signaling that the GPIB BUF has been powered on has successfully completed its self test and is ready to accept data e A means is provided by which very large files can be transferred without depleting the bandwidth of the GPIB Talker and the GPIB bus The following paragraphs explain how this last point can be beneficial Suppose that you need to send a file to a plotter via the GPIB BUF and the file is larger than the available memory in the GPIB BUF Since the plotter is a slow data acceptor and you are sending a large file the GPIB BUF buffer will most likely become full If this happens the GPIB bus as well as the GPIB Talker will bottleneck to the same speed as the plotter To avoid this problem the SRQ on empty function can be enabled and the GPIB Talker Controller can send data amounts up to but not exceeding the GPIB BUF buffer size The Controller can then unaddress the GPIB BUF and allow other devices to use the GPIB while the GPIB BUF is spooling the file to the target device The Controller also is now free to perform other work while the file is being spooled When the GPIB BUF has emptied its internal data buffer it then requests service using SRQ to indicate that it
14. ached to the GPIB OUT port Unless either the GPIB BUF or the target device is operating in listen only mode the target device must be set at the same GPIB address as the GPIB BUF If all the GPIB address switches are set to ON the GPIB BUF is configured to operate in listen only mode In this mode no addressing is required to make the GPIB BUF a GPIB Listener and it cannot be unaddressed to listen Therefore all data transferred on the GPIB IN port is accepted by the GPIB BUF and output to the target device When operating in listen only mode the GPIB BUF can neither return any data from the target device nor respond to a serial poll request since it cannot be addressed as a GPIB Talker As a consequence the SRQ feature of the GPIB BUF should not be enabled when operating in listen only mode When operating in listen only mode the GPIB BUF sends all possible listen addresses to the target device via the GPIB OUT port after it has finished its power on self test Since all listen addresses are sent out the target device need not be in listen only mode Instead it can be at any valid GPIB primary address This mode can also be used to connect more than one target device to the GPIB BUF which allows multiple simultaneous copies of a document or drawing to be created Data Transfers Upon being addressed to listen the GPIB BUF updates the front panel address indicators by turning on the LISTEN indicator and turning off the TALK indi
15. al kits available 28 oz 796 gm without power supply unit Appendix B Customer Communication For your convenience this appendix contains forms to help you gather the information necessary to help us solve technical problems you might have as well as a form you can use to comment on the product documentation Filling out a copy of the Technical Support Form before contacting National Instruments helps us help you better and faster National Instruments provides comprehensive technical assistance around the world In the U S and Canada applications engineers are available Monday through Friday from 8 00 a m to 6 00 p m central time In other countries contact the nearest branch office You may fax questions to us at any time Corporate Headquarters 512 795 8248 Technical support fax Branch Offices Australia Austria Belgium Denmark Finland France Germany Italy Japan Netherlands Norway Spain Sweden Switzerland U K 800 328 2203 512 794 5678 Phone Number 03 879 9422 0662 435986 02 757 00 20 45 76 26 00 90 527 2321 1 48 14 24 00 089 741 31 30 02 48301892 03 3788 1921 03480 33466 32 848400 91 640 0085 08 730 49 70 056 20 51 51 0635 523545 Fax Number 03 879 9179 0662 437010 19 02 757 03 11 45 76 71 11 90 502 2930 1 48 14 24 14 089 714 60 35 02 48301915 03 3788 1923 03480 30673 32 848600 91 640 0533 08 730 43 70 056 20 51 55 0635 523154 Technical Support For
16. cator The GPIB BUF then begins to accept data from the GPIB IN port using the onboard Direct Memory Access DMA Controller The GPIB BUF User Manual 3 2 National Instruments Corp Chapter 3 Technical Information DMA Controller transfers the data directly to the internal data buffer without processor intervention Thus GPIB transfer rates as high as 900 kbytes s are possible The GPIB BUF turns off the EMPTY indicator as soon as it starts receiving data from the host The buffered data is then sent to the target device connected to the GPIB OUT port at the maximum acceptance rate of the target device The GPIB OUT port is interrupt driven and is asynchronous with respect to any DMA activity that is taking place on the GPIB IN port Both events take place concurrently and without user intervention If very large amounts of data are sent to the GPIB BUF greater than the amount of RAM in the system and the target device is a very slow data acceptor such as a printer or plotter the internal data buffer of the GPIB BUF can become full If this happens the FULL indicator on the front panel illuminates This is not an error condition but an indication that the GPIB transfer rate from the GPIB Talker to the GPIB BUF has slowed to approximately the same rate as that of the target device accepting the data Upon being addressed to talk the GPIB BUF updates the front panel address indicators by turning on the TALK indicator and turning of
17. d to the rear panel 2 Remove the two screws on the opposite sides of the rear panel Warning Most of the circuitry in the GPIB BUF uses advanced CMOS technology and can be damaged by static electricity Avoid touching any of the components and take any necessary CMOS handling precautions 3 Grasp the rear panel bezel and pull it straight away from the rest of the unit The board should slide out the back of the enclosure 4 Locate the configuration DIP switch U38 on the printed circuit board 5 Set the switches for the desired configuration as described in the following section Set Configuration Switches 6 Close the unit and reinsert the rear panel screws National Instruments Corp 2 3 GPIB BUF User Manual Installation and Operation Chapter 2 Set Configuration Switches Use the DIP switch at location U38 on the printed circuit board to configure the GPIB primary address and operating modes of the GPIB BUF The DIP switch has eight configuration switches Figure 2 2 shows the factory default setting Key Bj depressed side of switch handle suet Figure 2 2 Factory Default Switch Settings Table 2 1 and Table 2 2 detail the possible configurations of the eight switches and what each configuration indicates For more information on the different operating modes configured by the switches refer to Chapter 3 Technical Information Default settings are in shaded rows Table 2 1 Configuration Param
18. e GPIB BUF Rear Panel 000 0 eeeeeeceeseeesecenceeeeeceeeenseeeeeeenees 1 4 The GPIB Connectors merene nean E EA AE 1 4 Chapter 2 Installation and Operation ccceccccessceesseeeesseeeeees 2 1 Instalatii ennes eien i E E E EAEE 2 2 Step 1 Inspect the GPIB BUF ssseeeseseseseeeereereresen 2 2 Step 2 Verify the Voltage Requirement 0000 2 2 Step 3 Configure the Operating Parameters 2 3 Set Configuration Switches 0 eee 2 4 Step 4 Connect the Cables i e eee eseeeeeeeees 2 6 Step 5 Power on the Unit eect cneeeees 2 7 Operationen sre hethen SARA tiie oleh te aoa oe REN tees Bove 2 7 Chapter 3 Technical Information 2 0 0 0 ceecesesceseeeseeeeteeseereeesneeneeeneens 3 1 Power Ups aerasi idee ares wand aed ase Gen abies 3 1 Addressing orreee inn irre eE Eaa E EEAS EEE En ETit 3 2 D ta Transfers n E E EE N E R OE E EEE ER 3 2 BOD TEE EE A S 3 3 TE O EA E T ee CRRA E E E 3 4 REN A et eee RIA 3 4 Polling the GPIB BUP c sesesessesesssseseseecenencnsenensevonense sence 3 5 Special Note About Timeouts cece ceeseececseececnseeeeae 3 8 Multiline Command Group eee eeeeeceeeseeeeceeeeeeeeeeeaeenen 3 8 National Instruments Corp vil GPIB BUF User Manual Contents Appendix A Hardware Specifications 0 0 0 ccccccccceceeeeeeeeeeeeeeeeeteeteesnees A 1 Appendix B Customer Communication 0 0 cece eeseeeeseeesneenees B 1 GOSS AE nenep Moss ee
19. e rene cone meas ue G 1 Figures Figure 1 1 The GPIB BUF rinii peccant nini 1 1 Figure 1 2 The GPIB BUF Front Panel sseseeeeeeseereeeereerersrerrerereen 1 3 Figure 1 3 The GPIB BUF Rear Panel seeeeeeeeeeeeeerrreerrerrererrreersn 1 4 Figure 1 4 The GPIB Connector and Signal Designations 1 5 Figure 2 1 GPIB BUF System Setup Example eee 2 1 Figure 2 2 Factory Default Switch Settings ee eeeeeeereeeee 2 4 Figure 3 1 Serial Poll Status Byte cece cess eeeeeeeeeeeeneeeeeeee 3 5 Tables Table 1 1 LED Descriptions sssrini inaen 1 3 Table 2 1 Configuration Parameters for Switches through 3 2 4 Table 2 2 Configuration Parameters for Switches 4 through 8 2 5 Table 3 1 Parallel Poll Responses 00 eeiee ec ceecesesseeseceeceeeeeeteeeeneees 3 7 Table A 1 Electrical Characteristics 0 0 00 eeeeceseesceeeesceeeeeeeeneeeeen A 1 Table A 2 Environmental Characteristics seseseeeesseeesrseeersrrerreeen A 1 Table A 3 Physical Characteristics e eseseeeessseeeesesseeeeseessessrersseeeen A 2 GPIB BUF User Manual viii National Instruments Corp About This Manual Introduction to the GPIB BUF The GPIB BUF is one of National Instruments family of MicroGPIB products These products are high performance low cost IEEE 488 support items packaged in small all metal cases capable of being rack mounted Organization of This Manual This manual is organized as foll
20. eters for Switches 1 through 3 en rs an Enables device clear recognition Disables device clear recognition Sends DCL to the target and resets the GPIB BUF Sends DCL to the target Disables SRQ on buffer empty Enables SRQ on buffer empty GPIB BUF User Manual 2 4 National Instruments Corp Chapter 2 Installation and Operation Table 2 2 Configuration Parameters for Switches 4 through 8 Switches 4 5 6 7 8 Indication OFF OFF OFF OFF OFF Sets GPIB primary address 0 OFF OFF OFF OFF ON Sets GPIB primary address 1 OFF OFF OFF ON OFF Sets GPIB primary address 2 OFF OFF OFF ON ON Sets GPIB primary address 3 OFF OFF ON OFF OFF Sets GPIB primary address 4 OFF OFF ON OFF ON Sets GPIB primary address 5 OFF OFF ON ON OFF Sets GPIB primary address 6 ON ON ON Sets GPIB primary address 7 OFF OFF OFF Sets GPIB primary address 8 OFF OFF ON Sets GPIB primary address 9 OFF ON OFF Sets GPIB primary address 10 OFF ON ON Sets GPIB primary address 11 ON OFF OFF Sets GPIB primary address 12 ON OFF ON Sets GPIB primary address 13 ON ON OFF Sets GPIB primary address 14 ON ON ON Sets GPIB primary address 15 OFF OFF OFF Sets GPIB primary address 16 OFF OFF OFF ON Sets GPIB primary address 17 ON OFF OFF ON OFF Sets GPIB primary address 18 ON OFF OFF ON ON Sets GPIB primary address 19 continues National Instruments Corp 2 5 GPIB BUF User Manual Installation and Operation Chapter 2 Table 2 2 Configuration Parameters for
21. f the LISTEN indicator The GPIB BUF waits for all the data in its internal buffer to be accepted by the target and then addresses the target device to talk Any data sent from the target device to the GPIB BUF is not buffered but is passed directly through the GPIB BUF to the GPIB IN port Since no buffer space is required when the GPIB BUF is addressed to talk all the RAM in the system can be dedicated to providing the largest possible buffer space for data coming into the GPIB IN port EOI The GPIB End Or Identify EOD signal is used by the GPIB Listener s to determine when the GPIB Talker has finished sending data Without it the GPIB Listener must either know in advance the exact amount of data that the Talker will send or must know of some terminating character sequence that the Talker will adhere to when sending data EOI signal reception and transmission is fully supported on the GPIB BUF When sending data while addressed as a GPIB Talker the GPIB BUF asserts EOI on the GPIB IN port with any byte received from the target device that has the EOI signal line asserted National Instruments Corp 3 3 GPIB BUF User Manual Technical Information Chapte r 3 When receiving data while addressed as a GPIB Listener the GPIB BUF buffers the state of the EOI signal line along with the data byte it corresponds to using an additional on board RAM module Therefore the GPIB BUF is able to maintain the EOI status with each byte recei
22. lot is finished and the prompt is received If the time required to finish the plot and respond to the prompt are longer than the time limit of the Controller a timeout error will occur This can be easily corrected by either increasing or disabling time limits on GPIB operations of this type to very slow data acceptors A more efficient way to handle responses after large file transfers is to wait until the GPIB BUF is empty before issuing the plotter request for information In this way timeouts can remain in effect and the GPIB Talker can perform other useful work because it will not hang while waiting for a plotter response If SRQs are enabled then the Controller need not continually poll the GPIB BUF but can instead wait for an SRQ before issuing the plotter request Multiline Command Group When the GPIB BUF receives either a GPIB Multiline Message SDC or DCL via the GPIB IN port it responds in one of several ways The response depends on the condition of switch 1 and 2 of the configuration switch at location U38 on the printed circuit board If switch 1 is on the GPIB BUF ignores any SDC and DCL received and takes no action If switch 1 is off default the GPIB BUF response depends on the condition of switch 2 If switch 2 is on the GPIB BUF immediately passes a DCL to the GPIB target device when a DCL or SDC is received If switch 2 is off default the GPIB BUF not only passes a DCL to the target device but also clears it
23. m Technical support is available at any time by fax Include the information from your configuration form Use additional pages if necessary Name Company Address Fax ___ Phone Computer brand Model Operating system Processor Speed MHz RAM MB Display adapter Mouse yes no Other adapters installed Hard disk capacity Instruments used MB Brand National Instruments hardware product model Revision Configuration National Instruments software product Version Configuration continues The problem is List any error messages The following steps will reproduce the problem Hardware Configuration Form Record the settings and revisions of your hardware on the line to the right of each item Update this form each time you revise your hardware configuration and use this form as a reference for your current configuration National Instruments Products e GPIB BUF Revision e Switch Settings Other Products e Computer Make and Model e Microprocessor e Clock Frequency e Type of Monitor Card Installed e Application Programming Language BASIC C Pascal and so on Documentation Comment Form National Instruments encourages you to comment on the documentation supplied with our products This information help
24. nna e Be sure that the equipment is plugged into a grounded outlet and that the grounding has not been defeated with a cheater plug Notice to user Changes or modifications not expressly approved by National Instruments could void the user s authority to operate the equipment under the FCC Rules If necessary consult National Instruments or an experienced radio television technician for additional suggestions The following booklet prepared by the FCC may also be helpful How to Identify and Resolve Radio TV Interference Problems This booklet is available from the U S Government Printing Office Washington DC 20402 Stock Number 004 000 00345 4 Contents About This Manual cists aieinnie onmnanaaunnawas ix Introduction to the GPIB BUP eeceesceeseeesseeeeeceeeeeeeeeeeeeenem ix Organization of This Manual eee cee ceeceeceeeeeesseeeeeee ix Conventions Used in This Manual cecceseecsseeeneeceeeeeseeee X Related Documentation eeeecesseeeecereesseeeseceeeeeseeceeeeeeenees xX Customer Communication eceescesceeseeceeeeseceeeceeceereesseeeeeeeees xX Chapter 1 Description of the GPIB BUF oo cceeeeeeeeseesees 1 1 Introductio aea eaea aaa Ei E EE R 1 1 What Your Kit Contains ee eeeeeseceeeeeseecenceceeeeesceeeeeecneeesese 1 2 Optional Equipment 0 cece eeeeeeese cee ceeceeeeeeeseeseesaeeesseeees 1 2 The GPIB BUF Front Panel 0 eee eeseesceeeeecsseeeeeceseeceeeeeneeenes 1 3 Th
25. ormation that you may find helpful as you read this manual e ANSI TEEE Standard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation e ANSVIEFE Standard 488 2 1987 IEEE Standard Codes Formats Protocols and Common Commands Customer Communication National Instruments wants to receive your comments on our products and manuals We are interested in the applications you develop with our products and we want to help if you have problems with them To make it easy for you to contact us this manual contains comment and configuration forms for you to complete These forms are in Appendix B Customer Communication at the end of this manual GPIB BUF User Manual x National Instruments Corp Chapter 1 Description of the GPIB BUF This chapter contains general information about the National Instruments GPIB BUF and lists components and accessories Introduction The GPIB BUF shown in Figure 1 1 is an IEEE 488 GPIB data buffer which increases GPIB performance by isolating a slow GPIB data acceptor from the rest of the GPIB system This increase in performance is reflected both in an increase in the GPIB bandwidth and a quicker release of the GPIB talker from the task of transferring data to a slow GPIB device In most cases the GPIB talker is a computer with other tasks to perform The faster it transfers data the sooner it can perform its next task Figure 1 1 The GPIB BUF National Instruments Co
26. ows Chapter 1 Description of the GPIB BUF contains general information about the National Instruments GPIB BUF and lists components and accessories Chapter 2 Installation and Operation describes the procedures for installing and operating the GPIB BUF Chapter 3 Technical Information contains a more detailed description of the operation of the GPIB BUF The timing characteristics of the parallel port are provided in this chapter Appendix A Hardware Specifications contains tables which specify the electrical environmental and physical characteristics of the GPIB BUF Appendix B Customer Communication contains forms you can use to request help from National Instruments or to comment on our products and manuals The Glossary contains an alphabetical list and a description of terms used in this manual including abbreviations acronyms metric prefixes mnemonics and symbols National Instruments Corp ix GPIB BUF User Manual About This Manual Conventions Used in This Manual The following conventions are used in this manual italic Italic text denotes emphasis a cross reference or an introduction to a key concept bold italic Bold italic text denotes a note caution or warning bold Bold text denotes the name of light emitting diode LED Abbreviations acronyms metric prefixes mnemonics symbols and terms are listed in the Glossary Related Documentation The following document contains inf
27. r reshipment If the equipment appears to be damaged do not attempt to operate it Contact National Instruments for instructions Step 2 Verify the Voltage Requirement The GPIB BUF is shipped from the factory with either a 115 V or 230 V wall mount power supply Verify that the voltage on the power supply matches the voltage that is supplied in your area Warning Operating the unit at any voltage other than the one specified could damage the unit GPIB BUF User Manual 2 2 National Instruments Corp Chapter 2 Installation and Operation Step 3 Configure the Operating Parameters The GPIB BUF is shipped from the factory configured to operate at a GPIB primary address of 5 with the SRQ on empty function disabled and device clear recognition and pass through enabled The address specified on the configuration switches should match the GPIB address of your target device If the addresses do not match you must either change the primary address of your target device or change the primary address of the GPIB BUF so that they correspond To change the primary address of your target device refer to the user manual of the device To change the GPIB BUF primary address the SRQ on empty function or the device clear response method you must open the unit and change the configuration switches The following steps describe how to change the configuration switches 1 Disconnect power to the GPIB BUF and disconnect any cables attache
28. rp 1 1 GPIB BUF User Manual Description of the GPIB BUF Chapter 1 The GPIB BUF has two isolated GPIB ports and is placed in line between a GPIB system and a single slower GPIB device usually a printer or plotter The GPIB BUF automatically buffers all device dependent data sent to the slower device Because the GPIB BUF can talk or listen on either port at any time the GPIB BUF provides fully transparent bi directional data transfers The target GPIB device appears to be connected directly to the TIEFE 488 bus What Your Kit Contains Your kit should contain the following components One of the following boxes e GPIB BUF 256 KB RAM 115 VAC 776226 02 e GPIB BUF 1 MB RAM 115 VAC 776226 03 e GPIB BUF 256 KB RAM 230 VAC 776226 32 e GPIB BUF 1 MB RAM 230 VAC 7716226 33 e GPIB BUF User Manual 320125 01 Optional Equipment Rack Mount Kit Single 1 unit 180480 01 Dual 2 units 180480 02 Double Shielded GPIB Cables GPIB Type X2 Cable 1 m 763061 01 GPIB Type X2 Cable 2 m 76306 1 02 GPIB Type X2 Cable 4 m 76306 1 03 GPIB BUF User Manual 1 2 National Instruments Corp Chapter 1 Description of the GPIB BUF The GPIB BUF Front Panel The power switch and six Light Emitting Diodes LEDs are mounted on the GPIB BUF front panel Figure 1 2 shows the front panel of the GPIB BUF NATIONAL GPIB BUF gt INSTRUMENTS IEEE 488 lt _ IEEE 488 BUFFER POWER READY TALK LISTEN E
29. runs internal diagnostics to verify the operation of all internal circuitry Since the diagnostics can take as long as 20 s the READY LED blinks during the test to indicate that the power on self test is progressing successfully If no errors are found the GPIB BUF illuminates the READY and EMPTY LEDs which indicates that the GPIB BUF is ready to operate and its internal data buffer is empty If the GPIB BUF is in listen only mode it also illuminates the LISTEN LED at this time After the GPIB BUF has successfully completed its power on self test it asserts the Interface Clear IFC signal on the GPIB OUT port to initialize the link between the GPIB BUF and the target device and to establish the ability of the GPIB BUF to address the target device The GPIB BUF then reads the status of the configuration switches and initializes the rest of the system National Instruments Corp 3 1 GPIB BUF User Manual Technical Information Chapte r 3 If the SRQ on empty feature is enabled the GPIB BUF asserts the Service Request SRQ signal on the GPIB IN port The SRQ condition can be used to signal the GPIB Controller that the GPIB BUF is powered on and ready to accept data Addressing The five GPIB address switches U38 switches 4 through 8 become the GPIB primary address to which the GPIB IN port responds These switches are also used to determine the talk and listen addresses used by the GPIB BUF when addressing the target device att
30. s GPIB BUF User Manual 3 8 National Instruments Corp Chapter 3 Technical Information internal data buffer This mode can be used to prematurely abort a lengthy plot or print Neither Group Execute Trigger GET Go To Local GTL nor Local Lockout LLO have any effect on the GPIB BUF The GPIB IN port on the GPIB BUF can only act as a GPIB Talker or Listener It should not be passed control If it is the GPIB circuitry in the GPIB BUF will accept control and immediately assert ATN This is an error condition that can lock up your system and therefore should be avoided National Instruments Corp 3 9 GPIB BUF User Manual Chapter 1 Description of the GPIB 232CV Appendix A Hardware Specifications This appendix lists the electrical environmental and physical specifications of th Table A 1 Electrical Characteristics Characteristic Specification Power Supply Unit Wall mount type 115 VAC or 230 VAC 50 60 Hz input 9 VDC 1A max output Table A 2 Environmental Characteristics Characteristic Specification Operating Temperature 0 to 40 C Storage Temperature 20 to 70 C Relative Humidity 10 to 90 noncondensing conditions Noise Emissions FCC Class A Verified Hardware Specifications Characteristic Rack Mounting Appendix A Table A 3 Physical Characteristics Specification 1 6 in by 5 7 in by 8 4 in 40 6 mm by 144 8 mm by 213 4 mm All metal enclosure Single or du
31. s us provide quality products to meet your needs Title GPIB BUF User Manual Edition Date February 1994 Part Number 320125 01 Please comment on the completeness clarity and organization of the manual continues If you find errors in the manual please record the page numbers and describe the errors Thank you for your help Name Title Company Address Phone Mail to Technical Publications National Instruments Corporation 6504 Bridge Point Parkway MS 53 02 Austin TX 78730 5039 Fax to Technical Publications National Instruments Corporation MS 53 02 512 794 5678 Glossary 2 degrees percent A amperes AC alternating current ANSI American National Standards Institute C Celsius EMI electromagnetic interference FCC Federal Communications Commission GPIB General Purpose Interface Bus Hz hertz IEEE Institute of Electrical and Electronic Engineers in inches KB kilobytes of memory LED light emitting diode m meters MB megabytes of memory oz ounce RAM random access memory s seconds VAC volts alternating current VDC volts direct current
32. taken care of automatically by the GPIB BUF All data operations are completely transparent and the target device appears to be connected directly to the GPIB bus You should operate and control your target device in the same manner you would if you did not have a GPIB BUF National Instruments Corp 2 7 GPIB BUF User Manual Chapter 3 Technical Information This chapter contains a more detailed description of the operation of the GPIB BUF The timing characteristics of the parallel port are provided in this chapter The GPIB BUF is actually a powerful 8 bit microcomputer tailored for use as an IEEE 488 data buffer The operating system of the unit is contained in Read Only Memory ROM and can address up to 1 MB of dynamic Random Access Memory RAM The GPIB BUF microprocessor contains an integrated Direct Memory Access DMA Controller for high speed data transfers from the GPIB circuitry The processor also contains an integrated memory management unit a dynamic RAM Controller a clock generator a programmable timer unit a full duplex UART and an interrupt Controller Two LSI GPIB Controller chips which are programmed and maintained by the operating system provide all GPIB functionality Both controller chips are connected to their respective ports through GPIB transceivers which are responsible for guaranteeing that the electrical characteristics of the IEEE 488 specification are upheld Power Up When powered on the GPIB BUF
33. ved even when the DMA Controller is transferring data directly to memory In this way the GPIB BUF can accept multiple occurrences of EOI bytes at full speed without loss of performance due to special EOI handling techniques IFC Interface Clear IFC is used by a GPIB Controller to place an interface system in a known quiescent state The function of the IFC signal is to halt current operations on the bus by unaddressing all Talkers and Listeners and disabling serial polls The GPIB BUF asserts IFC on the GPIB OUT port once at power up for 500 us The action of asserting IFC for at least 100 us initializes the GPIB link to the target device and establishes the ability of the GPIB BUF to address the target device Any other response to IFC is not defined by the IEEE 488 specification and is specific to the target device If the GPIB BUF detects IFC asserted on the GPIB IN port it immediately unaddresses itself unless it is in listen only mode and stops accepting data IFC does not clear the GPIB BUF data buffer or assert IFC on the GPIB OUT port since either of these operations aborts any current data transfer taking place to the target device Device CLear DCL or Selected Device Clear SDC should be used to terminate an ongoing data transfer to the target device REN Remote Enable REN is asserted by the system Controller and is used to enable GPIB devices to be placed in the remote programming mode programmable via the
34. 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 manual 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 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

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