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GPIB-110 User Manual - National Instruments

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1. C L LE C AH SH via C via T via C via C C C via C via C via C via C via C via C via C via C via C via C PP via C C AH T TE via C via C via C SR GPIB 110 User Manual Multiline Interface Messages Appendix B Interface Message Reference List Continued Remote Messages Sent Continued Mnemonic STB TCT UNL UNT GPIB 110 User Manual Message status byte take control unlisten untalk B 6 Interface Function s via T TE via C via C via C National Instruments Corporation Appendix C Operation of the GPIB This appendix describes some basic concepts you should understand to operate the GPIB It also contains a description of the physical and electrical characteristics as well as configuration requirements of the GPIB History of the GPIB The GPIB is a link or bus or interface system through which interconnected electronic devices communicate Hewlett Packard invented the GPIB which they call the HP IB to connect and control programmable instruments manufactured by them Because of its high data transfer rates of over 1 Mbytes s the GPIB gained popularity in other applications such as intercomputer communication and peripheral control It was later accepted as the industry standard ANSI IEEE Standard 488 1987 The versatility of the system prompted the name General Purpose Interface Bus Types of Messages Devices on the
2. GPIB 110 User Manual 3 2 National Instruments Corporation Chapter 3 Theory of Operation After the GPIB 110 is turned on the GPIB transceivers are in a passive receive state not driving anything on the GPIB The extender remains in this state until communication is established with the remote GPIB 110 unit Once the link is established the GPIB 110 is able to monitor the local GPIB state and receive packets containing the remote GPIB state System Controller Detection The GPIB 110 monitors the location of the System Controller with the System Controller detection circuitry When IFC or REN true is received from the local GPIB the Local System Controller LSC state becomes true The X IFC or X REN signal is then sent true to the communication circuitry where it is sent to the remote unit The LSC state is cleared if R IFC or R REN is received true from the remote unit and IFC or REN is not true on the local GPIB R IFC or R REN true is received from the remote GPIB 110 unit the Remote System Controller RSC state becomes true The IFC and REN signals are then driven onto the local GPIB The RSC state is cleared if IFC or REN true is sensed from the local bus and R IFC or R REN is not received true Active Controller Detection The GPIB 110 monitors the location of the Active Controller with the Active Controller detection circuitry The location of the Active controller is determined by sensing the location of ATN After powe
3. and the GPIB 110 shuts down the GPIB drivers The unit then waits for link establishment Refer to the section Link Establishment Protocol earlier in this chapter System Timing and Transmission Clock System timing for serial communication is based on the Transmit Clock which is determined by the configuration switch setting The clock starts when the start bit of a packet is received so that it can be synchronized to receive the incoming packet The clock is then used to transmit the acknowledging packet When the packet transmission has completed the clock stops The unit then waits for the next packet to be received Upon power on or when the link is not established the clock is started in the GPIB 110 master unit to allow packet transmission to proceed GPIB 110 User Manual 3 6 National Instruments Corporation Appendix A Hardware Specifications This appendix lists the specifications of the GPIB 110 System Configuration Distance per extension Up to 2 km Loading per extension Up to 14 additional devices Multiple extensions Permitted in any combination of star or linear pattern GPIB driver output circuit and T1 timing No restrictions automatic conversion to 0 5 usec of source device T1 delay on remote side is built in Note is the data settling time DIO valid to DAV and varies according to the type of drivers and the system configuration used Performance Characteristics Speed Up to 144 kbytes sec speed
4. interface message reference list B 4 to B 6 list of B 2 to B 3 local messages received B 4 remote messages received B 4 to B 5 remote messages sent B 5 to B 6 N NDAC signal not data accepted C 4 NRED signal not ready for data C 4 O operating characteristics A 2 operation of the GPIB See also theory of operation configuration restrictions C 6 to C 7 GPIB signals data lines C 3 GPIB cable connector illustration C3 handshake lines C 3 to C 4 interface management lines C 4 overview C 2 history of the GPIB C 1 physical and electrical characteristics C 5 to C 6 role of extenders and expanders C 6 to C 7 System Controller and Active Controller C2 Talkers Listeners and Controllers C 1 to C 2 types of messages C 1 National Instruments Corporation Index P packets packet format 3 7 Receive Packet state 3 7 Transmit Packet state 3 7 Parallel Poll Response modes ANSI IEEE Std 488 1987 response requirement 2 9 Latched PPR mode 2 10 mixed mode option 2 10 response time problems 2 9 theory of operation 3 4 to 3 5 Unlatched PPR mode 2 10 performance characteristic specifications A 1 to A 2 physical and electrical characteristics description of C 5 to C 6 linear configuration of GPIB devices illustration C 5 star configuration of GPIB devices illustration C 6 physical restrictions on configuration C 6 to C 7 physical specifications A 3 power switch 2 4 powering on t
5. 025 21 026 22 027 23 030 24 031 25 032 26 033 27 034 28 035 29 036 30 037 3 Device Clear Appendix B Multiline Interface Messages ASCII NUL SOH STX ETX EOT ENQ ACK BEL BS ET LF VT FF CR SO SI DLE DCI DC2 DC3 DC4 NAK SYN ETB Group Execute Trigger Go To Local Local Lockout My Listen Address GPIB 110 User Manual Msg GTL SDC PPC GET TCT LLO DCL PPU SPE SPD Hex Oct 20 040 21 041 22 042 23 043 24 044 25 045 26 046 27 047 28 050 29 051 2A 052 2B 053 2C 054 2D 055 2E 056 2F 057 30 060 31 061 32 062 33 063 34 064 35 065 36 066 37 067 38 070 39 071 3A 072 3B 073 3C 074 3D 075 3E 076 3F 077 MSA MTA PPC PPD Dec ASCII Msg 32 SP MLAO 33 MLAI 34 MLA2 35 MLA3 36 MLA4 37 MLAS 38 amp MLA6 39 7 40 MLAS8 41 MLA9 42 d MLAIO 43 MLAI11 44 j MLA12 45 MLA13 46 MLA14 47 MLA15 48 0 16 49 1 17 50 2 18 51 3 19 52 4 MLA20 53 5 MLA21 54 6 MLA22 55 7 MLA23 56 8 MLA24 57 9 MLA25 58 MLA26 59 MLA27 60 MLA28 61 MLA29 62 gt MLA30 63 UNL My Secondary Address My Talk Address Parallel Poll Configure Parallel Poll Disable National Instruments Corporation Appendix B PPE PPU SDC SPD Multiline Interface Messages Multiline Interface Messages Oct Dec ASCII 100 64 101 65 A 102 66 B 103 67 C 104 68 D 105 69 E 106 70 F 107 71 G 110 72 H 111 73
6. Controller can make itself the CIC GPIB Signals and Lines The interface bus consists of 16 signal lines and 8 ground return or shield drain lines The 16 signal lines are divided into three groups e Eight data lines e Three handshake lines Five interface management lines GPIB 110 User Manual C 2 National Instruments Corporation Appendix C Operation of the GPIB Figure C 1 shows the arrangement of these signals on the GPIB cable connector je DIOS DIO6 DIO7 DIO8 REN GND Twisted Pair with DAV GND Twisted Pair with NRFD GND Twisted Pair with NDAC GND Twisted Pair with IFC GND Twisted Pair with SRQ GND Twisted Pair with ATN SIGNAL GROUND Figure C 1 GPIB Cable Connector Data Lines The eight data lines DIO1 through DIOS carry both data and command messages commands and most data use the 7 bit ASCII or ISO code set in which case the 8th bit DIO8 is unused or used for parity The GPIB command messages are listed in Appendix B Multiline Interface Messages Handshake Lines Three lines asynchronously control the transfer of message bytes among devices The process is called a three wire interlocked handshake and it guarantees that message bytes on the data lines are sent and received without transmission error National Instruments Corporation GPIB 110 User Manual Operation of the GPIB Appendix C NRFD not ready for data NRED indicates when a device is r
7. GPIB 110 If this happens set all signals on the Master Controller to normal 1 unit load This is done by using a back panel switch It is also important to limit the cabling to no more than 2m per device National Instruments Corporation 2 13 GPIB 110 User Manual Chapter 3 Theory of Operation This chapter contains an overview of the GPIB 110 and explains the operation of each part of the GPIB 110 The GPIB 110 design consists of two main parts The extension circuitry e serial communication circuitry The extension circuitry monitors the local GPIB states and converts the signals monitored into the X for transmit signals that are sent to the serial communication circuitry The serial communication circuitry samples the X signal lines and serializes the information into packets that are transmitted to the remote GPIB 110 unit The serial communication circuitry decodes packets received from the remote unit and converts the packets into the parallel GPIB signals prefixed with an R for receive that are sent to the extension circuitry The extension circuitry monitors the R signal lines and drives the local GPIB lines accordingly National Instruments Corporation 3 1 GPIB 110 User Manual Theory of Operation Chapter 3 Figure 3 1 shows a block diagram of the GPIB 110 Selftest Mode Power On ae System Timing and Transmit y Transmission Clock Clock System Controller Packet Transmi
8. GPIB communicate by passing messages through the interface system The two types of messages are device dependent messages and interface messages e Device dependent messages often called data or data messages contain device specific information such as programming instructions measurement results machine status and data files Interface messages manage the bus itself They are usually called commands or command messages Interface messages perform such tasks as initializing the bus addressing and unaddressing devices and setting devices for remote or local programming The term command as used here should not be confused with some device instructions which are also called commands Such device specific instructions are actually data messages Talkers Listeners and Controllers A Talker sends data messages to one or more Listeners The Controller manages the flow of information on the GPIB by sending commands to all devices Devices can be Talkers Listeners and or Controllers A digital multimeter for example is a Talker and can also be a Listener A printer or plotter is usually only a Listener A computer on the GPIB often combines all three roles to manage the bus and communicate with other devices The GPIB is a bus like a typical computer bus except that the computer has its circuit cards interconnected via a backplane bus whereas the GPIB has stand alone devices interconnected via a cable bus National Instruments Co
9. This switch is located on the rear panel of the GPIB 110 2 Disconnect the power cord from the power source and from the rear panel of the GPIB 110 3 Remove the cover from the GPIB 110 by first removing the two screws located on each side of the housing Lift off the cover To isolate the interface cable shield from the chassis power ground and logic ground change the interface cable Shield Selection Jumper shown in Figure 2 1 letter c to the position labeled ISO National Instruments Corporation 2 1 GPIB 110 User Manual Configuration and Installation Chapter 2 To isolate the digital logic ground from the chassis and power ground change the chassis ground to Logic Ground Selection jumpers shown in Figure 2 1 letter a to the position labeled ISO Replace the cover Be sure the aluminum side plates are in the proper place Replace the screws you removed in Step 3 Pre 6 Reconnect the power cord GPIB 110 Rear Panel Top View a Chassis Ground to Logic Ground Selection b Fiber Optic Coaxial Selection Jumpers 00S IV 00S TV 1 i 42 95 x c Interface Cable Shield Selection 0115 016 0117 0118 0119 E 73 076 E gt EN Un C Tr 0 097 gt zgje E z ir e A za R12 Cc tt gt gt 5 Figure 2 1 Isolation Selection GPIB 110 User Manual 2 2 National Instruments Corporation Chapter 2 Configuration and Inst
10. 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 2o tte uaa eiie taba eli s ix Organization of This Manual Conventions Used in This ed een aee YS X Related Documentations i HE OI EVO REA N ERE Eee X Customer Communicationsin eda Y X Chapter 1 Description of the GPIB 110 1 1 What Your Kit Should Contain ater terere eroi ene Ee VY epe 1 3 Optional Equipment oos perte cedere aste nn en ne nd Ud Pisos tats 1 4 Bird Spr nie 1 4 Chapter 2 Configuration and Installation 2 1 Grounding COMMS UAL OM mm 2 1 The GPIB 110 Front and Rear Panels sees enne 2 3 The GPIB 110 Front Panel ioni tty ec eei ERI de eR 2 3 Th GPIB 110 Rear Panel nn teintes 24 2 5 Cable eii E M 2 6 Coaxial Cable Setup tn TS ne ee retenir ste 2 6
11. bIber OpBbec Cable 2 7 Master Switch acr M AE 2 7 Biber Optic Transmit POWBESs 2 7 Transmit C106 RE RE 2 8 Extension Amd 2 8 Immediate Bxtenston Modes eo dise wd Deco E 2 8 AN AIL OUE S cole 2 9 Parallel Poll Response PPR Modes ss 2 9 Latched PPR Mode Approach D cocer Leto idest etr adc sien eo A ira nee 2 10 Unlatched PPR Mode Approach 2 ss 2 10 Mixed Mode dm nn as Ts dato 2 10 Installations 2 11 aby cana E A cesses L NARA an ERs o NE 2 11 PIG WET ADI S E ae es omoia ot ende aca etico 2 11 Sel t rest Modes ceo cate ses M ere 2 11 Self Test with Coaxial Cable 2 12 Self Test with Iaber Optic C able Re b assu dii NUR dh 2 12 Connecting to Hewlett Packard HP Controllers 2 13 Chapter 3 Theory of Operation ics odo oae a nn 3 1 Extension ne ER RSS ane nn 3 2 POWA Olmada ne RE nn Ms MALE II CO E MT Ae 3 2 National Instruments Corporation v GPIB 110 User Manual Contents System Controller Detection si ese etienne ie Poen eo noel eun 3 3 Active Controller D tection meneren Ie ei POR UI UA DANS 3 3 Source Hand
12. between GPIB instruments up to 2 km Transfer rates up to 144 kbytes s Choice of fiber optic or coaxial cable Passes control over the GPIB FCC Class A verified noise emission Optional rack mount hardware The high speed GPIB 110 Bus Extender shown in Figure 1 1 is used in pairs with serial fiber optic or coaxial cables to connect two separate GPIB or IEEE 488 bus systems in a functionally transparent manner While the two bus systems are physically separate as shown in Figure 1 2 devices operate as if located on the same bus as shown in Figure 1 3 GPIB 110 BUS EXTENDER SERIAL COMMLINICATION Figure 1 1 The Model GPIB 110 Bus Extender National Instruments Corporation 1 1 GPIB 110 User Manual Description of the GPIB 110 Chapter 1 At short distances the data transfer rate over the extension can exceed 144 kbytes s The transfer rate degrades as the distance increases There is no speed degradation for transfers between devices on the same side of the extension Because the GPIB 110 is a functionally transparent extender the same GPIB communications and control programs that operate with an unextended system work unmodified with an extended system When conducting a parallel poll with an extended system minor modifications are necessary These are explained in the section titled Parallel Poll Response PPR Modes in Chapter 2 of this manual Fiber Optic or Coaxial Cable GPIB 1 GPIB 110 GPIB 110 GPIB 2 Comput
13. 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 antenna 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
14. depends on type of serial link and distance See Table A 1 No limitation to device speeds when there are no listeners on remote side of extension Table A 1 Performance Versus Distance Performance Cable Cable Length Max Data Transfer Fiber Optic 144 0 108 0 85 0 56 0 44 0 36 0 Rate kbytes sec Coaxial 144 0 108 0 33 0 17 9 1 6 0 4 Max SRQ Prop Fiber Optic 11 0 14 0 18 0 27 0 35 0 44 0 Delay usec Coaxial 11 6 14 8 35 4 67 0 378 0 1450 0 Max Parallel Poll Fiber Optic 17 0 21 0 26 0 38 0 48 0 58 0 Response Delay usec Coaxial 23 9 30 8 53 2 98 0 606 0 2340 0 National Instruments Corporation 1 GPIB 110 User Manual Hardware Specifications Functionality Interlocked IEEE 488 handshake IEEE 488 capability identification codes Operating Characteristics Architecture Operating modes Parallel poll response modes Electrical Characteristics GPIB interface circuit Transmission interface circuit GPIB 110 User Manual Appendix A Transparent GPIB operation except for latched parallel polls Maintained across the extension Complete source handshake AHI Complete acceptor handshake TS TES Complete Talker L3 LE3 Complete Listener SRI Complete service request RLI Complete remote local PP1 2 Complete parallel poll DC1 Complete device clear DTI Complete device trigger 1 5 Complete controller E2 Tri state GPIB drivers Synchronous clocked design point to point n
15. is used to detect serial transmission errors The GPIB 110 recovers automatically from detected errors National Instruments also manufactures a parallel extender the GPIB 130 This extender relays the instantaneous status of all GPIB signals over an RS 422 compatible cable and allows up to a 300 m extension The National Instruments GPIB 120A is a high speed GPIB expander that allows up to 14 additional devices to be connected to the bus and 20 m of cable length to be added to the system In addition optical isolation is provided between the two connected GPIBs to prevent ground loop and noise problems Only one GPIB 120A is required per expansion National Instruments Corporation C 7 GPIB 110 User Manual Appendix D 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 sup
16. message has been detected on the local GPIB If the Active Controller REM LED 15 lit ATN has been received from the remote unit If the Source Handshake LOC LED is lit a Data Valid DAV message has been detected on the local GPIB that is the Talker is on the local GPIB If the REM LED lights up DAV has been received from the remote unit that is the Talker 1s on the remote side National Instruments Corporation 2 3 GPIB 110 User Manual Configuration and Installation Chapter 2 The GPIB 110 Rear Panel The GPIB 110 rear panel is shown in Figure 2 2 The rear panel contains all the GPIB 110 connectors and switches OPTICAL FIBER Figure 2 2 Rear Panel The rear panel shown is for the 776103 03 776103 33 model which supports both fiber optic and coaxial cable For all models the power switch is located on the upper right corner of the rear panel The fuse housing is located directly to the right of the power switch The GPIB connector is located directly below the power switch and is labeled GPIB To the left of the GPIB connector center bottom of panel is the configuration switch which is labeled CONFIGURATION For the 776103 01 776103 31 and 776103 03 776103 33 models an LED is located to the left of the configuration switch The LED labeled FO SIGNAL OK is lit when the signal quality received over the fiber optic cable is good To the left of the LED are the optical fiber connectors labeled RCVR for receive
17. of cable For a coaxial cable you must reduce the transmit clock values as the cable length increases Set Switches 8 9 and 10 on the rear panel configuration switch so the transmit clock value corresponds to your cable length Table 2 1 shows the appropriate transmit clock values versus cable length Table 2 1 Transmit Clock Values Versus Cable Length Cable Type Cable Length Transmit Clock Configuration Switch Setting 10 9 8 Coaxial m to 240m Cable 240 m to 425 m 425 m to 730m 730 m to 1035 m 1035 m to 1340 m 1340 m to 1765 m 1765 m to 2000 m Note 0 2 Off 1 ON Fiber Optic Any Length 10 MHz 1 1 1 Cable Extension Modes The GPIB 110 has two extension modes Immediate Extension mode and IFC Wait mode Both GPIB 110 units in the extension system must be set to the same mode using Switch 5 which is located on the rear panel configuration switch Immediate Extension Mode The GPIB 110 is set at the factory to the Immediate Extension mode Switch 5 OFF In this mode the extenders connect the two local GPIB buses as soon as they are both turned on GPIB 110 User Manual 2 6 National Instruments Corporation Chapter 2 Configuration and Installation IFC Wait Mode In IFC Wait Mode Switch 5 ON the GPIB 110s do not connect the two local GPIB buses until an IFC signal is detected This mode requires a System Controller on one side of the extension and any number of Talkers Listeners and other Controllers in
18. the number of devices on the bus is limited The following restrictions are typical Amaximum separation of 4 m between any two devices and an average separation of 2m over the entire bus Amaximum total cable length of 20 m e No more than 15 devices connected to each bus with at least two thirds of the devices turned on You can usually connect a cluster of lab instruments without exceeding these restrictions However many applications require longer cable spans or additional loading From the time the GPIB was invented the need existed for bus extenders and expanders repeaters Extenders connect two separate buses via a transmission medium and the distance between the buses can be quite long Expanders or repeaters generally buffer one bus from an adjacent bus that doubles the total cable and loading limits The GPIB 110 is a serial extender that uses either low cost coaxial cable or high performance electrically isolated fiber optic cable as its transmission medium The GPIB 110 samples GPIB signals on each bus to which it is connected serializes the information encoded in small packets and transmits the packets to the remote side Separate packets are sent for each message or byte handshaking maintaining GPIB synchronization between both connected buses The GPIB 110 uses a handshake protocol that allows it to maintain optimum communication between both extenders in the link In addition a low bit cyclical redundancy code
19. the system This mode causes the GPIB 110s to be synchronized with the local buses so that the buses do not disturb each other when the GPIB 110s are turned on In IFC Wait mode the two GPIB 110s wait to detect the following information in this sequence 1 The Interface Clear IFC signal from the System Controller 2 The Attention ATN signal from the Active Controller 3 The Data Valid DAV signal from the Active Controller or Talker Both units turn on in a quiescent condition without an active local or remote state They remain this way until one unit detects an IFC true from the System Controller that is on the same contiguous bus That unit enters the Local System Controller LSC state and causes the other unit to enter the Remote System Controller RSC state The IFC and Remote Enable REN signals are switched to flow from the local to the remote unit Next one unit detects the Attention ATN signal from the Active Controller enters the Local Active Controller LAC state and places the other unit in the Remote Active Controller RAC state The ATN signal is switched to flow from the local to the remote side and the Service Request SRQ is switched to flow in the opposite direction Finally one unit detects the Data Valid DAV signal from the Source Handshake function of the Talker or Active Controller That unit enters the Local Source LS state and places the other unit in the Remote Source RS state The DAV and Data DIO si
20. volts alternating current watts Glossary 2 National Instruments Corporation Index A abbreviations and acronyms used in the manual vi Active Controller LEDs for 2 3 theory of operation 3 3 ATN line attention C 4 C cables coaxial cable setup 2 6 fiber optic cable setup 2 7 GPIB cable connector illustration C 3 jumper settings for selecting 2 6 overcoming length restrictions 1 3 COAX connector 2 4 coaxial cable self test mode 2 13 setting up 2 6 commands or command messages C 1 configuration cable selection 2 6 coaxial cable setup 2 6 extension modes 2 8 to 2 9 fiber optic cable setup 2 7 grounding configuration 2 1 to 2 2 IFC Wait Mode 2 9 Immediate Extension Mode 2 8 master switch setting 2 7 Parallel Poll Response modes 2 9 to 2 10 role of extenders and expanders C 6 to C 7 settings for configuration switch 2 5 system configuration specifications A 1 transmit clock 2 8 configuration switch default settings 2 5 illustration of 2 5 location of 2 4 possible configurations for 2 5 connectors and switches See also jumpers National Instruments Corporation COAX connector 2 4 coaxial cable setup 2 6 configuration switch 2 4 2 5 fiber optic cable setup 2 7 Fiber Optic Transmit Power setting 2 7 GPIB connector 2 4 IFC Wait Mode 2 9 Immediate Extension Mode 2 8 master switch setting 2 7 RCVR connector 2 4 on rear panel of GPIB 110 2 4 TRANS connector 2
21. 4 NRFD not ready for data C 4 Hewlett Packard controllers 2 13 history of the GPIB C 1 I IFC line interface clear C 4 GPIB 110 User Manual IFC Wait Mode 2 9 Immediate Extension Mode 2 8 installation See also configuration connecting to Hewlett Packard controllers 2 13 front panel 2 3 mounting the GPIB 110 2 11 overview 2 1 power on 2 11 procedure for 2 11 rear panel 2 4 Self Test mode 2 11 to 2 12 unpacking the GPIB 110 1 4 interface management lines ATN attention C 4 EOI end or identify C 4 IFC interface clear C 4 REN remote enable C 4 SRQ service request C 4 J jumpers See also connectors and switches grounding isolation selection illustration 2 2 setting for cable selection 2 6 L Latched PPR mode 2 11 LEDs for Active Controller 2 3 ERR 2 3 FO SIGNAL OK 2 4 LINK 2 3 LOC 2 3 PWR LED 2 3 REM 2 3 Serial Communication LEDs 2 3 for Source Handshake 2 3 for System Controller 2 3 light emitting diodes See LEDs link establishment protocol 3 6 LINK LED 2 3 3 6 Listeners C 2 LOC LED 2 3 local state definition of 2 3 National Instruments Corporation M Master Controller preloading 2 13 master switch setting Fiber Optic Transmit Power setting 2 7 overview 2 7 messages See also multiline interface messages commands or command messages C 1 data or data messages C 1 mounting the GPIB 110 2 11 multiline interface messages
22. 4 Controllers Controller in Charge C 2 role of Controller C 2 customer support vii D data direction control 3 5 data lines C 3 data or data messages C 1 DAV signal data valid C 4 documentation abbreviations used in the manual vi acronyms used in the manual related documentation E electrical specifications A 2 environmental specifications A 3 EOI operation of 3 5 EOI line end or identify C 4 equipment optional 1 4 ERR LED 2 3 error detection and recovery for serial communication 3 7 to 3 8 extenders and expanders limitations on C 7 operation of C 6 to C 7 extension circuitry definition of 3 1 GPIB 110 User Manual Index extension modes IFC Wait Mode 2 9 Immediate Extension Mode 2 8 F fiber optic cable Fiber Optic Transmit Power setting 2 7 self test mode 2 12 setting up 2 6 FO SIGNAL OK LED 2 4 front panel of GPIB 110 2 3 G GPIB 110 bus extender See also operation of the GPIB theory of operation block diagram 3 2 contents of kit 1 3 definition of 1 1 description of 1 1 to 1 3 features of 1 1 illustration of 1 1 logical configuration illustration 1 2 models of 2 1 optional equipment 1 4 physical configuration illustration 1 2 physical restrictions on C 6 to C 7 grounding configuration isolation of grounds 2 1 to 2 2 isolation selection illustration 2 2 overview 2 1 H handshake lines DAV data valid C 4 NDAC not data accepted C
23. E LE PP PP PP PP National Instruments Corporation Appendix B Interface Message Reference List Continued Remote Messages Received Continued Mnemonic PPRn PPU Remote Messages Sent Mnemonic REN RFD RQS SDC SPD SPE SRQ STB TCT or TCT UNL ATN DAB DAC DAV DCL END GET GTL IDY IFC LLO MLA or MLA MSA or MSA MTA or MTA OSA OTA PCG PPC PPD PPE PPRn PPU REN RFD RQS SDC SPD SPE SRQ Message parallel poll response n parallel poll unconfigure Message remote enable ready for data request service selected device clear serial poll disable serial poll enable service request status byte via L LE take control unlisten attention data b yte data accepted data valid device clear end group execute trigger go to local identify interface clear local lockout my listen address my secondary address my talk address other secondary address other talk address primary command group parallel poll configure parallel poll disable parallel poll enable parallel poll response n parallel poll unconfigure remote enable ready for data request service selected device clear serial poll disable serial poll enable service request National Instruments Corporation B 5 Multiline Interface Messages Interface Function s via C PP Interface Function s RL SH via L LE DC T TE T TE via C
24. GPIB 110 User Manual August 1994 Edition Part Number 320052 01 Copyright 1986 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 Limited Warranty The GPIB 110 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 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 docum
25. I 112 74 J 113 75 K 114 76 L 115 77 M 116 78 N 117 79 O 120 80 P 121 81 Q 122 82 R 123 83 S 124 84 T 125 85 U 126 86 V 127 87 W 130 88 X 131 89 Y 132 90 Z 133 91 134 92 135 93 136 94 137 95 _ Parallel Poll Enable Parallel Poll Unconfigure Selected Device Clear Serial Poll Disable National Instruments Corporation Msg MTAO MTAI MTA2 MTA3 MTA4 MTAS MTA6 MTA7 MTA8 MTA9 MTAIO MTAII 12 MTA13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 0 Hex Oct 60 140 61 141 62 142 63 143 64 144 65 145 66 146 67 147 68 150 69 151 6A 152 6B 153 6C 154 6D 155 6E 156 6F 157 70 160 71 161 72 162 73 163 74 164 75 165 76 166 77 167 78 170 79 171 7A 172 7B 173 7C 174 7D 175 176 TF 177 SPE TCT UNL UNT B 3 kel ON 104 OBB TAT RQ CS 112 CA z lt ner 119 120 121 122 123 124 125 Me TON 127 DEL Serial Poll Enable Take Control Unlisten Untalk ASCII Msg MSAO PPE MSA1 PPE MSA2 PPE MSA3 PPE MSA4 PPE MSAS PPE MSA6 PPE MSA7 PPE MSA8 PPE MSA9 PPE MSAIO PPE MSA11 PPE MSA12 PPE MSA13 PPE MSA14 PPE MSA15 PPE MSA16 PPD MSA17 PPD MSA18 PPD MSA19 PPD MSA20 PPD MSA21 PPD MSA22 PPD MSA23 PPD MSA24 PPD MSA25 PPD MSA26 PPD MSA27 PPD MSA28 PPD MSA29 PPD M
26. SA30 PPD GPIB 110 User Manual Multiline Interface Messages Appendix B Interface Message Reference List Local Messages Received by interface functions Mnemonic gts Ist lon pe Itn lun nba pon rdy 15 ISV rtl sic sre tca tcs ton Message go to standby individual status qualifier listen only local poll enable listen local unlisten new byte available power on ready request parallel poll request system control request service return to local send interface clear send remote enable take control asynchronously take control synchronously talk only Remote Messages Received Mnemonic ATN DAB DAC DAV DCL END GET GTL IDY IFC LLO MLA MLA MSA or MSA MTA MTA OSA OTA PCG PPC PPD PPE GPIB 110 User Manual Message attention data byte data accepted data valid device clear end group execute trigger go to local identify interface clear local lockout my listen address my listen address my secondary address my talk address my talk address other secondary address other talk address primary command group parallel poll configure parallel poll disable parallel poll enable B4 Interface Function s SH AH T TE L LE SR RL PP C Bgook Interface Function s SH AH T TE L LE PP C via L LE SH AH DC via L LE DT RL L LE PP T TE L LE C RL L LE RL T TE LE T TE L TE T TE T
27. Whenever from the local bus or R ATN changes state When ATN or DAV is received from the remote unit e During a parallel poll The Remote Source RS Handshake state is cleared during the following events When IFC Wait Mode is selected with Switch 5 on the rear panel configuration switch and before the Active Controller is identified e Whenever there is a change in state from the remote signal When ATN or DAV is received from the local GPIB e During a parallel poll Until the LS state is true and unless a parallel poll is in progress the unit drives the local NRFD signal passively false After the Active Controller is identified if in IFC Wait mode and until the Source Handshake is identified the unit drives NDAC true Thus the unit appears to the local GPIB to be in a normal RFD NDAC state awaiting the first data or command byte When DAV is received from the Local GPIB the LS state becomes true DAV is then sent to the remote unit as X DAV When R DAV is received from the remote unit the signal is delayed 2 us and the RS state becomes true Once the RS state 15 true DAV 15 driven onto the local GPIB Subsequently whenever R DAV true is received from the remote unit the signal is delayed 500 ns before being driven onto the local GPIB to satisfy T1 The local NRED and NDAC are sensed and sent to the remote unit as X RFD and X DAC Once the LS state 1s true the propagation of R RFD from the remote side allows
28. a change occurs or when the 3 us time period has expired the current state of the GPIB is sampled and the Transmit Packet state is entered Transmit Packet State In the Transmit Packet state the GPIB state information is serialized and start bits and sequence numbers are added As the packet is transmitted the cyclical redundancy check code is generated and appended to the packet When this step is complete the Receive Wait state is entered Error Detection and Recovery In the GPIB 110 a communication error is recognized in one of two ways e Ifa packet is not received within a certain time limit from the previous transmission the remote unit is turned off and the GPIB 110 shuts down the GPIB 110 drivers and waits for resumption of communication as it does with the Link Establishment Protocol Refer to the section Link Establishment Protocol earlier in this chapter National Instruments Corporation 3 7 GPIB 110 User Manual Theory of Operation Chapter 3 e Ifa packet is received containing an error the GPIB 110 attempts to recover from the error A packet is received with an error if the cyclical redundancy check is wrong or the sequence number is wrong If either of these packet errors is detected the packet is discarded The GPIB 110 then retransmits the packet it had previously sent If two or more packets with errors are received in succession the GPIB 110 unit assumes that the remote unit or the link is malfunctioning
29. ailures 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 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 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 appropriat
30. allation The GPIB 110 Front and Rear Panels In the following discussions the terms ocal and remote refer to certain states of the two GPIB 110 Bus Extenders When one extender is in a local state meaning that the state in question originated on its side the other extender is in the corresponding remote state The three states in question are the System Controller Active Controller and Source Handshake The GPIB 110 Front Panel The GPIB 110 front panel is shown in Chapter 1 Figure 1 1 The front panel has nine Light Emitting Diodes LEDs The PWR LED on the left side of the front panel lights up whenever power is applied to the GPIB 110 The Serial Communication LEDs are LINK and ERR error The GPIB 110 condenses the 16 IEEE 488 signals into data packets that are sent across the serial link and are converted back to IEEE 488 signals by the remote GPIB 110 When lit the LINK LED indicates that the remote GPIB 110 is on and the extension is operating normally The ERR LED flashes whenever a data packet containing an error is received The System Controller Active Controller and Source Handshake each have two LEDs indicating local LOC and remote REM If the System Controller LOC LED is lit the Interface Clear IFC or Remote Enable REN message has been detected on the local GPIB If the System Controller REM LED is lit IFC or REN has been received from the remote unit If the Active Controller LOC LED is lit the Attention ATN
31. and TRANS for transmitter For the 776103 02 and 776103 03 models the coaxial cable connector is located on the left most bottom corner of the rear panel The connector is labeled COAX GPIB 110 User Manual 2 4 National Instruments Corporation Chapter 2 Configuration and Installation GPIB 110 Setup Configure the GPIB 110 units before installing them and running the cable between them This step makes configuration easier The main configuration switch is used to select other operating modes This switch is located on the rear panel of the GPIB 110 and in most cases is the only switch you need to set before installing the GPIB 110s Be sure to power off the GPIB 110 before changing any switches Figure 2 3 shows the default settings of the configuration switch position of switch handle CONFIGURATION Figure 2 3 Configuration Switch The GPIB 110 has a label on the bottom of the box with important information This label shows the ten configuration switches with their names The bottom left corner of the label lists the Fiber Optic Transmit power settings For more information on setting these switches refer to the section titled Fiber Optic Transmit Power later in this chapter The bottom right corner of the label lists the configuration switch settings for Switches 8 through 10 and the corresponding Transmit Clock Values For more information refer to the section titles Transmit Clock later in this chapter Figure 2 4 sho
32. atched Parallel Poll mode When the Parallel Poll Response is received from the remote unit and the local EOI signal goes false the Parallel Poll In Progress state becomes false This event causes the Parallel Poll register to latch the Parallel Poll Response when operating in latched Parallel Poll mode The extender then stops driving NRFD true Data Direction Control The unit drives the GPIB data lines DIO1 8 from R DIO1 8 if there is a local Parallel Poll in progress or if the RS state is true and a remote Parallel Poll is not in progress Otherwise these lines are not driven When a packet containing DAV true or RPP true is received and unlatched parallel poll response mode is selected the GPIB data lines are driven with the data from the data packet received from the remote unit If DAV is not true during a Parallel Poll the data lines are driven from the Parallel Poll Response register The local unit sends the data lines to the remote unit via X DIO1 8 if there is a remote Parallel Poll in progress or if the LS state is true and a local Parallel Poll is not in progress Otherwise the data bytes are not sent EOI The local unit transmits EOI to the remote unit as X EOI if the LS state is true X EOI is asserted from the start of a local Parallel Poll until the poll handshake signal is received from the remote unit and the local poll completes X EOI is received as R EOI at the remote unit X EOI propagates to the remote GPIB if
33. capacity M Brand Instruments used National Instruments hardware product model Revision Configuration National Instruments software product Version Configuration The problem is List any error messages The following steps will reproduce the problem GPIB 110 Hardware and Software Configuration Form Record the settings and revisions of your hardware and software on the line to the right of each item Update this form each time you revise your software or hardware configuration and use this form as a reference for your current configuration National Instruments Products e GPIB 110 Revision e Remote GPIB 110 Revision e National Instruments GPIB Interface e National Instruments Software e Fiber Optic or Coax Cable or Both Length of cable Other Products e Computer Make and Model e Operating System Version e Number of GPIB Devices on Bus e Other Boards in System GPIB Devices in System e Other Cables in Systems Type and Manufacturer Length of cable Documentation Comment Form National Instruments encourages you to comment on the documentation supplied with our products This information helps us provide quality products to meet your needs Title GPIB 110 User Manual Edition Date August 1994 Part Number 320052 01 Please comment on the completeness clarity and organization of the manual If you f
34. cceptable electrical outlet 100 to 120 VAC or 220 to 240 VAC depending upon which model of the GPIB 110 you have Then plug the other end of the power cord into the back panel of the GPIB 2 Link the first GPIB to the GPIB 110 with an appropriate cable Type X1 or better The cable coming from the GPIB should be plugged into the back panel of the GPIB 110 3 Link the second GPIB to the remote GPIB 110 with the appropriate GPIB cable Mounting The GPIB 110 enclosure is designed for table top or rack mount operation Single and dual unit rack mount kits are available from National Instruments Power On The GPIB 110 extension system is fully operational when power is applied to both units and they are connected If the extenders are set for IFC Wait Mode it may be necessary to turn on the System Controller last after the extenders and all other devices are operating This step is necessary if the System Controller executes only one IFC shortly after power on The preferred operating mode is to keep both extenders and at least two thirds of the devices on both buses turned on when there is any GPIB activity Self Test Mode The GPIB 110s are equipped with a Self Test mode that determines if the GPIB 110 receivers transmitters and packet transmission and reception circuitry are operating correctly This mode is controlled by Switch 4 This mode should be used only if you want to check the operation of the GPIB 110 It is not nece
35. connectors and switches system configuration specifications A 1 System Controller Controller in Charge C 2 LEDs for 2 3 theory of operation 3 3 system timing and transmission clock for serial communication 3 8 GPIB 110 User Manual T Talkers Listeners and Controllers C 1 to C 2 technical support vii theory of operation See also operation of the GPIB Active Controller detection 3 3 block diagram of GPIB 110 3 2 data direction control 3 5 EOI 3 5 overview 3 1 parallel polling 3 4 to 3 5 powering on the GPIB 110 3 2 serial communication circuitry error detection and recovery 3 7 to 3 8 link establishment protocol 3 6 system timing and transmission clock 3 8 serial communication protocol overview 3 6 packet format 3 7 Receive Packet state 3 7 Receive Wait state 3 7 Transmit Packet state 3 7 transmit synchronization state 3 7 Source Handshake detection 3 3 to 3 4 SRQ 3 5 System Controller detection 3 3 TRANS connector 2 4 transmit clock configuring 2 8 system timing for serial communication values versus cable length table 2 8 Transmit Packet state 3 7 Transmit Synchronization state 3 7 U Unlatched PPR mode 2 10 unpacking the GPIB 110 1 4 National Instruments Corporation
36. d by encoded GPIB information and terminated by a cyclical redundancy check code Each packet also contains a sequence number Receive Wait State The Receive Wait state is entered after a packet has been transmitted to the remote unit The GPIB 110 has a timeout circuit that corresponds to twice the propagation delay of 2 km of cable plus a GPIB 110 transmit wait time and the time it takes to transmit one packet This equals approximately 26 us plus the time it takes to transmit one packet which varies depending on the transmit clock used If a packet is not received within this time the GPIB 110 goes into an error state Once packet is received the Receive Wait state is exited and the Receive Packet state 15 entered Receive Packet State In the Receive Packet state a packet is received and converted into parallel information as it is received A redundancy check code is generated for the packet as it is received This code is compared with the cyclical redundancy check code appended to the packet If an error is detected the packet is discarded Otherwise the packet information is latched and sent to the extension circuitry The GPIB 110 then enters the Transmit Synchronization state Transmit Synchronization State In the Transmit Synchronization state the GPIB 110 waits up to approximately 3 us for a change to occur on the local GPIB A change consists of a change in the state of the IFC REN ATN DAV or RFD GPIB signals When
37. e GPIB 110 power switch to OFF 2 Disconnect the fiber optic cable from the rear panel transmit and receiver connectors 3 Connect the transmitter connector to the receiver connector with a single fiber optic cable 4 Setthe master switch to the ON position Switch 6 OFF and the self test switch to the ON position Switch 4 OFF 5 Turn the GPIB 110 power switch to ON At this point the LINK LED on the front panel lights up indicating that the Self Test mode is operating correctly The ERR LED should remain off Note Be sure to turn the self test switch to the OFF position Switch 4 ON and the master switch to the original position and reconnect the fiber optic extension cable before re using the GPIB 110 GPIB 110 User Manual 2 12 National Instruments Corporation Chapter 2 Configuration and Installation Connecting to Hewlett Packard HP Controllers To achieve high data transfer rates and long cable spans between devices many HP controllers and computers such as the 64000 series use a preload technique on the unit designated Master Controller When preloaded the GPIB lines of the Master Controller are terminated to represent six device loads HP has two types of preloading Class A in which all 16 GPIB lines are loaded and Class B in which all except Not Ready For Data NRFD and Not Data Accepted NDAC messages are loaded Preloading increases ringing on signal transitions and can cause improper operation of the
38. e 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 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
39. eady not ready to receive a message byte The line is driven by all devices when receiving commands and by Listeners when receiving data messages NDAC not data accepted NDAC indicates when a device has or has not accepted a message byte The line is driven by all devices when receiving commands and by Listeners when receiving data messages DAV data valid DAV tells when the signals on the data lines are stable valid and can be accepted safely by devices The Controller drives DAV when sending commands and the Talker drives it when sending data messages The way in which NRFD and NDAC are used by the receiving device is called the Acceptor Handshake Likewise the sending device uses DAV in the Source Handshake Interface Management Lines Five lines are used to manage the flow of information across the interface ATN attention The Controller drives ATN true when it uses the data lines to send commands and false when it allows a Talker to send data messages IFC interface clear The System Controller drives the IFC line to initialize the bus to become CIC REN remote enable The System Controller drives the REN line which is used to place devices in remote or local program mode SRQ service request Any device can drive the SRQ line to asynchronously request service from the CIC with the SRQ line EOI end or identify The EOI line has two purposes The Talker uses it to mark the end of a message string T
40. ed PPR Mode Approach 1 This mode is selected by setting Switch 7 ON Most Controllers pulse the IDY signal for a period of time exceeding 2 us and expect a response within that time When used with this type of Controller the GPIB 110 must be set in the Latched PPR mode After power on the initial poll response is FFH subsequent poll responses are the results of the previous poll In this mode the local GPIB 110 extender responds to IDY by outputting the contents of the PPR data register At the same time a parallel poll message is sent to the remote bus and the poll response is returned to the local unit When the local IDY signal is unasserted the register is loaded with the new remote response Consequently the register contains the response of the previous poll To obtain the response of both the local and remote buses the control program executes two parallel polls back to back and uses the second response The software driver library of most Controllers contains an easy to use parallel poll function For example if the function is called PPOLL and the control program is written in BASIC the sequence to conduct a poll in Latched PPR mode might be like this CALL PPOLL PPR CALL PPOLL PPR IF PPR gt 0 GOTO NNN If two GPIB extender systems are connected in series three polls are necessary to get responses from the local middle and far buses Unlatched PPR Mode Approach 2 Many Hewlett Packard GPIB Controllers remain
41. ent 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 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 f
42. er System Controller Talker and Listener Printer Multimeter Signal Generator Listener Talker and Listener Listener Unit Under Test Figure 1 2 Typical GPIB 110 Extension System Physical Configuration Computer System Controller Printer Multimeter Signal Generator Talker and Listener Listener Talker and Listener Listener Unit Under Test Figure 1 3 Typical GPIB 110 Extension System Logical Configuration GPIB 110 User Manual 1 2 National Instruments Corporation Chapter 1 Description of the GPIB 110 With the GPIB 110 you can overcome the two following configuration restrictions imposed by ANSI TEEE Standard 488 1987 e Cable length limit of 20 m per contiguous bus or 2 m times the number of devices on the bus whichever is smaller Electrical loading limit of 15 devices per contiguous bus Each GPIB 110 system extends the distance limit by 2 km and the loading limit to 30 devices including the extenders You can connect these point to point extender systems in series for longer distances or in star patterns for additional loading What Your Kit Should Contain Your GPIB 110 kit should contain the following components Kit Component Part Number Model GPIB 110 Bus Extender 100 120 VAC Fiber Optic Version 776103 01 Coaxial Version 776103 02 Dual Fiber Optic and Coaxial Capability 776103 03 220 240 VAC Fiber Optic Version 776103 31 Coaxial Version 776103 32 Dual Fiber Optic am
43. ge and System Controller C2 GPIB Signals and Lines iie units C 2 DA RENT C 3 Handshake Lines C 3 NRED not ready for data ede beo etudes C4 NDAC not ACCS PLE date i C4 DAV data valid C4 Interface Management Lines ee ER C 4 ACTIN ir rre C 4 SCR too C4 REN remote enable ins C4 service TEQUOSD eva aan ena i aee e C4 BOT end Or identify C 4 GPIB 110 User Manual vi National Instruments Corporation Contents Physical and Electrical Characteristics 5 Configuration Restrictions The Role of Extenders and Expanders C 7 Appendix D Customer Communication D 1 RS Dre ee 1 Index 1 Figures Figure 1 1 The Model GPIB 110 Bus Extehder 5 peer 1 1 Figure 1 2 Typical GPIB 110 Extension System Physical Configuration 1 2 Figure 1 3 Typical GPIB 110 Extension System Logical Configuration 1 2 Figure 2 1 Isolation auo id ua d Rudd 2 2 Figure 2 2 Rear Panel obe ee ote e dao tec t gt 24 Figure 2 3 Con
44. gnals are switched to flow from local to remote side and the Not Ready for Data NRFD and Not Data Accepted NDAC signals are switched to flow from remote to local side As the source side for these three key signals IFC ATN and DAV change the local remote states of each extender change The directions of the other GPIB signals change accordingly See the Active Controller Detection and Source Handshake Detection sections in Chapter 3 for more information about this operation Parallel Poll Response PPR Modes According to the ANSI IEEE Standard 488 1987 devices must respond to a parallel poll within 200 ns after the Identify IDY message is asserted by the Active Controller which then waits 2 us or more to read the Parallel Poll Response PPR A remote device on an extended system cannot respond this quickly because of cable propagation delay GPIB extender manufacturers have approached this problem in three ways Approach 1 Respond to IDY within 200 ns with the results of the previous poll of the remote bus Approach 2 Ignore the 200 ns rule and assume the Controller will wait sufficiently long to capture the response Approach3 Do not support parallel polling at all National Instruments Corporation 2 9 GPIB 110 User Manual Configuration and Installation Chapter 2 The GPIB 110 supports either Approach 1 or 2 selected by Switch 7 which is located on the rear panel configuration switch as shown in Figure 2 3 Latch
45. he CIC uses it to tell devices to identify their responses in a parallel poll GPIB 110 User Manual C 4 National Instruments Corporation Appendix C Operation of the GPIB 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 at each end This design allows devices to be connected in either a linear or a star configuration or a combination of the two See Figures C 2 and C 3 GPIB Cables Device A Device B Figure C 2 Linear Configuration of the GPIB Devices National Instruments Corporation C 5 GPIB 110 User Manual Operation of the GPIB Appendix C GPIB Cables Device B Device C Figure C 3 Star Configuration of GPIB Devices The standard connector is the Amphenol or Cinch Series 57 Microribbon or Amp Champ type An adapter cable using non standard cable and or connector is used for special interconnect applications The GPIB uses negative logic with standard transistor transistor logic TTL levels For example when DAV is true it is a TTL low level 0 8 V and when DAV is false it is a TTL high level 2 2 0 V GPIB 110 User Manual C 6 National Instruments Corporation Appendix C Operation of the GPIB Configuration Restrictions The Role of Extenders and Expanders To achieve the high data transfer rate that the GPIB is designed for the physical distance between devices and
46. he GPIB 110 after installation 2 11 theory of operation 3 2 preloading of Master Controller 2 13 PWR LED 2 3 R RCVR connector 2 4 rear panel of GPIB 110 2 4 Receive Packet state 3 7 Receive Wait state 3 7 REM LED 2 3 remote state definition of 2 3 REN line remote enable C 4 S Self Test mode coaxial cable self test 2 12 fiber optic cable self test 2 12 GPIB 110 User Manual Index overview 2 11 serial communication circuitry definition of 3 1 error detection and recovery 3 7 to 3 8 link establishment protocol 3 6 serial communication protocol overview 3 6 packet format 3 7 Receive Packet state 3 7 Receive Wait state 3 7 Transmit Packet state 3 7 transmit synchronization state 3 7 system timing and transmission clock theory of operation 3 6 to 3 7 Serial Communication LEDs 2 3 signals data lines C 3 GPIB cable connector illustration C 3 handshake lines DAV data valid C 4 NDAC not data accepted C 4 NRFD not ready for data C 4 interface management lines ATN attention C 4 EOI end or identify C 4 IFC interface clear C 4 REN remote enable C 4 SRQ service request C 4 Source Handshake LEDs for 2 3 theory of operation 3 3 to 3 4 specifications electrical A 2 environmental A 3 operating characteristics A 2 performance characteristics A 1 to A 2 physical A 3 system configuration A 1 SRQ operation of 3 5 SRQ line service request C 4 switches See
47. in a parallel poll state with IDY asserted whenever they are not performing another function A change in the response causes an interrupt of the control program In other Controllers the IDY signal is toggled on and off and the duration of the signal can vary to accommodate delayed responses over extenders When used with these types of Controllers the GPIB 110 should be set to Unlatched PPR mode by setting Switch 7 to the OFF position This means that the IDY message is sent to the remote bus and the response is returned as fast as propagation delays allow It is the responsibility of the Controller to wait long enough for the response Mixed Mode Option If there are multiple Controllers and all of the same type are located on the same side of the extension the two GPIB 110 units can be set to Latched and Unlatched PPR modes accordingly GPIB 110 User Manual 2 10 National Instruments Corporation Chapter 2 Configuration and Installation Installation After configuring both GPIB 110s and connecting the coaxial or fiber optic cable follow these instructions Verify the Voltage Requirement The GPIB 110 is shipped from the factory with either a 100 to 120 VAC or 220 to 240 VAC internal power supply Verify that the voltage specified on the power supply matches the voltage supplied in your area Caution Operating the unit at any voltage other than the one specified could damage the unit 1 Plug the utility power cord into an a
48. ind 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 Fax to Technical Publications National Instruments Corpor ation National Instruments Corporation 6504 Bridge Point Parkway MS 53 02 MS 53 02 Austin TX 78730 5039 512 794 5678 Glossary ROMAIN 9 kbytes LAC LED LOC LS degrees is greater than or equal to is less than or equal to ohms percent amperes Active Controller alternating current American Standard Code for Information Exchange refers to coaxial cable connector Celsius Controller In Charge central processing unit decibels direct current End or Identify Error bit Federal Communications Commission fiber optic General Purpose Interface Bus Hewlett Packard hertz Identify message Interface Clear inches International Standards Organization 1 000 bytes Local Active Controller light emitting diode Local LED Local Source state National Instruments Corporation Glossary 1 GPIB 110 User Manual Glossary LSC m MB Mbytes NA GPIB 110 User Manual Local System Controller meters megabytes of memory 1 000 000 bytes numerical aperture Parallel Poll Response Polyvinylchloride Remote Active Controller Remote LED Remote Source state Remote System Controller seconds transistor transistor logic volts
49. n Operating the GPIB 110 at any voltage other than the one specified could damage the unit GPIB 110 User Manual 1 4 National Instruments Corporation Chapter 2 Configuration and Installation This chapter contains instructions for configuring installing and verifying the operation of the GPIB 110 Users unfamiliar with the GPIB should first read Appendix C Operation of the GPIB to become familiar with GPIB terminology and protocol before continuing with this chapter The GPIB 110 comes in the following three models 776103 01 776103 31 model Uses an optical fiber cable The 776103 02 776103 32 model Uses a coaxial cable The 776103 03 776103 33 model Uses either type of cable The GPIB 110 has several configurations depending on the type and length of cable used and other operating conditions Grounding Configuration A U S standard 3 wire power cable is provided with the GPIB 110 When connected to a power source this cable connects the equipment chassis to the power ground The GPIB 110 is shipped from the factory with the logic ground of the digital circuitry connected to both the power and chassis ground and interfacing cable shields If it is necessary to isolate either of these grounds to prevent current loops between units disassemble the unit according to the following instructions Y Warning Hazardous voltage inside Remove power cord before opening unit Turn the power switch to OFF
50. ntains instructions for configuring installing and verifying the operation of the GPIB 110 Chapter 3 Theory of Operation contains an overview of the GPIB 110 and explains the operation of each part of the GPIB 110 Appendix A Hardware Specifications lists the specifications of the GPIB 110 Appendix B Multiline Interface Messages lists the multiline interface messages and describes the mnemonics and messages that correspond to the interface functions These functions include initializing the bus addressing and unaddressing devices and setting device modes for local or remote programming The multiline interface messages are IEEE 488 defined commands that are sent and received with ATN TRUE Appendix C Operation of the GPIB describes some basic concepts you should understand to operate the GPIB It also contains a description of the physical and electrical characteristics as well as configuration requirements of the GPIB Appendix D 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 description of terms used in this manual including abbreviations acronyms metric prefixes mnemonics and symbols The ndex contains an alphabetical list of key terms and topics in this manual including the page where you can find each one National Instruments Corporation ix GPIB 110 User Manual About This Ma
51. nual 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 monospace Text in this font denotes sections of code and names of functions Abbreviations acronyms metric prefixes mnemonics symbols and terms are listed in the Glossary Related Documentation The following manual contains information that may be helpful as you read this manual ANSI IEEE Standard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation 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 D Customer Communication at the end of this manual GPIB 110 User Manual x National Instruments Corporation Chapter 1 Description of the GPIB 110 This chapter contains general information about the National Instruments GPIB 110 lists the contents of the GPIB 110 kit and explains how to unpack the GPIB 110 kit The GPIB 110 is a high performance bus extender with the following features Transparent to user software Extends the distance
52. ord from the power source and from the rear panel of the GPIB 110 3 Remove the cover from the GPIB 110 by first removing the two screws located on each side of the housing Lift off the cover 4 The Internal Cable Selection Jumper shown in Figure 2 5 is located underneath the transformer near the rear panel See Figure 2 1 letter b for the exact location Using needle nosed pliers right angle works best place the two blue jumpers on the correct setting The position labeled FO is for fiber optic cable The position labeled CX 15 for coaxial cable 5 Replace the cover Be sure the aluminum side plates are in the proper place 6 Replace the screws you removed in Step 3 7 Reconnect the power cord Coaxial Cable Setup The coaxial cable should be connected to the Coaxial BNC connector on the rear panel of the GPIB 110 When using a coaxial cable Switch 4 on the rear panel configuration switch must be set to ON Self Test mode OFF and Switches 5 through 10 must be configured as explained in the following sections Refer to Figure 2 3 for the default settings of the configuration switch and Figure 2 4 for other possible configurations GPIB 110 User Manual 2 6 National Instruments Corporation Chapter 2 Configuration and Installation Fiber Optic Cable Setup The fiber optic cable comes with two SMA style connectors on each end One connector should be marked T for transmit the other should be marked R for receive Connec
53. ot multidrop transmission Immediate extension or IFC wait extension Latched parallel poll response or unlatched parallel poll response Duplex transceivers with tri state drivers for IFC ATN DAV and EOI MC3448 and the DIO lines DS75160AN Duplex transceivers with open collector drivers for REN SRQ NRFD and NDAC MC3441 Optically isolated coaxial drivers 75121 and receivers 75122 with BNC connectors Optical transmitter HFM201 0 224 and receiver HEM1011 221 with SMA style optical cable connectors A 2 National Instruments Corporation Appendix A Hardware Specifications Table A 2 Electrical Specifications Characteristic Specification Power Supply Unit 100 to 120 VAC 50 to 50 Hz or 220 to 240 VAC 50 to 60 Hz Maximum Current 100 to 120 VAC 200mA Requirement 220 to 240 VAC 100mA Fuse Rating and Type 100 to 120 VAC 300mA 250V SLOBLO UL CSA Approved 220 to 240 VAC 200mA 250V SLOBLO IEC Approved Caution Replacement fuses should be the correct type and rating Refer to the section entitled Electrical Characteristics for fuse information Environmental Characteristics Operating temperature 0 to 45 C Humidity 596 to 9596 non condensing conditions ECC Class A verified Physical Characteristics Case style CS2 Size 3 5 in by 8 5 in by 13 in 89 mm by 216 mm by 330 mm Case material UL94V 0 flame retardant polystyrene Dow 60875F or equivalent Rack mounting Single or dual ki
54. p Coaxial Capability 776103 33 Power Cord U S standard 3 wire power cable 763000 01 GPIB 110 User Manual 320052 01 National Instruments Corporation 1 3 GPIB 110 User Manual Description of the GPIB 110 Chapter 1 Optional Equipment You can call National Instruments to order the following optional equipment to go with your kit Equipment Part Number Rack Mount Kit Single Rack Mount Kit 180304 01 Dual Rack Mount Kit 180304 02 Transmission Cable Type Fiber Optic Cable 178058 xxx Type T4 Coaxial Cable 178057 xxx xxx length in meters Type X2 GPIB Cable 1m 763061 01 2m 763061 02 4m 763061 03 8m 763061 04 For plenum cables contact National Instruments Unpacking Follow these steps when unpacking your GPIB 110 1 Verify that the pieces contained in the package you received match the kit parts list given earlier in this chapter Before you operate the GPIB 110 inspect the shipping container and its contents for damage Keep the packaging material for possible inspection and or reshipment If the equipment appears to be damaged do not attempt to operate it Contact National Instruments for instructions If the damage appears to have been caused in shipment file a claim with the carrier The GPIB 110 is shipped from the factory with a 100 to 120 VAC or 220 to 240 VAC power supply Verify that the voltage on the power supply matches the voltage that is supplied in your area Cautio
55. port fax 800 328 2203 512 794 5678 Branch Offices Phone Number Australia 03 879 9422 Austria 0662 435986 Belgium 02 757 00 20 Denmark 45 76 26 00 Finland 90 527 2321 France 1 48 14 24 00 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 UK 0635 523545 National Instruments Corporation D 1 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 GPIB 110 User Manual Technical Support Form Photocopy this form and update it each time you make changes to your software or hardware and use the completed copy of this form as a reference for your current configuration Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently If you are using any National Instruments hardware or software products related to this problem include the configuration forms from their user manuals Include additional pages if necessary Name Company Address Fax Phone Computer brand Model Processor Operating system Speed MHz RAM M Display adapter Mouse yes no Other adapters installed Hard disk
56. r on the Remote Active Controller RAC and Local Active Controller LAC states are cleared When ATN is received from the local bus the LAC state becomes true on the leading edge of ATN X ATN is then sent to the remote unit LAC true allows the local unit to receive SRQ from the remote unit and to drive the SRQ line on the local bus LAC is cleared if R ATN is received from the remote unit and ATN is false on the local GPIB When R ATN is received from the remote unit the RAC state becomes true When RAC is true the local signal is driven according to the state of R ATN received from the remote side The local state of SRQ is sent to the remote side that is to the Active Controller RAC is cleared if ATN is true on the local GPIB and R ATN is received false If IFC Wait mode is selected both the RAC and LAC states remain cleared until either the LSC or the RSC state is true Source Handshake Detection The GPIB 110 monitors the location of the Source Handshake The location of the Source Handshake is determined by the location of DAV The Local Source LS Handshake and Remote Source RS Handshake states are cleared upon power on National Instruments Corporation 3 3 GPIB 110 User Manual Theory of Operation Chapter 5 The LS Handshake state is also cleared on the following events e When IFC Wait mode is selected with Switch 5 on the rear panel configuration switch and before the Active Controller is identified e
57. received If a packet is not received the GPIB 110 times out and retransmits the packet This process continues until a packet is received When you power on the non master GPIB 110 waits to receive a packet from the master GPIB 110 unit The extender link 15 established when a GPIB 110 receives two successive packets without errors When the packets are received the LINK LED on the front panel lights up indicating that the remote unit is turned on and operating properly The extension is then operational When the remote unit no longer receives packets the extender times out turns off the LINK LED and stops driving the local GPIB Serial Communication Protocol The extender Serial Communication Protocol consists of each extender transmitting a packet whenever one is received while the link is established In this way each GPIB 110 unit can monitor that the remote unit is still on Transmission and reception of packets consists of four states e Receive Wait state e Receive Packet state e Transmit Synchronization state e Transmit Packet state If a communication error occurs the GPIB 110 attempts to recover from the error as explained in the section Error Detection and Recovery later in this chapter GPIB 110 User Manual 3 6 National Instruments Corporation Chapter 5 Theory of Operation Packet Format Information is sent between GPIB 110 units via digital packets The packet is made up of one or more start bits followe
58. rporation C1 GPIB 110 User Manual Operation of the GPIB Appendix C The role of the GPIB Controller can also be compared 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 usually addresses a Talker and a Listener before the Talker can send its message to the Listener After the message 15 transmitted the Controller usually unaddresses both devices Some bus configurations do not require a Controller For example one device may only 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 must be changed The Controller function is usually handled by a computer With the GPIB interface board your personal computer plays all three roles e Controller manages the GPIB e Talker sends data e istener receives data Controller In Charge and System Controller Although there can be multiple Controllers on the GPIB only one Controller at a time is Active Controller or Controller in Charge CIC Active control can be passed from the current Active Controller to an idle Controller Only one device on the bus the System
59. shake 3 3 Parallel Polling ouo 3 4 Data Direction 3 5 RE 3 5 SRO 3 5 Serial Communication 3 6 Link Establishment 3 6 Serial Communication Protocol ss 3 6 lis cedido 3 7 RECEIVE Walt State iue ive Y 3 7 Recerve Packet boe t a er POPE RO EAD RS 3 7 Transmit Synchronization State 3 7 Transmit Packet State oc ee E Pana maa e a 3 7 Error Detection and R covety iue eite 3 7 System Timing and Transmission Clock 3 8 Appendix A Hardware Specifications tutte te teen oai M etat A 1 System CONTIBUTAUON 2 2 en AED E SEHR TREAT int 1 Performance Characteristics ed br et deua o o 1 Operating Characteristics sissi sennior nne epo da e ee Leiva te bo eee e up ee ia pud A 2 Electrical o ee iet RS tee ne A 2 Environmental 3 Physical Charactersugs 3 Appendix Multiline Interface Messages 2222222 0 02041222 tenete B 1 Appendix C Operation of the GPIB rb AU dc C 1 History of the GPIB 1 ESSO 1 Talkers Listeners and Controllers iris C 1 Controller in Char
60. smit Power is adjustable from 12 5 percent to 100 percent power Operating the fiber optic transmitter at a lower power decreases power dissipation in the GPIB 110 and can extend the life of the optical transmitter The transmit power setting depends on the length of optical fiber cable used Switches 1 2 and 3 are used to set the transmit power of the transmitter LED Figure 2 3 shows the default settings for each switch and Figure 2 4 shows the power settings for the configuration switch settings You must determine which power setting to use when the GPIB 110s are connected with the fiber optic cable The following steps list how to determine the power setting Turn on both GPIB 110s 2 Set the transmit power switches on one of the GPIB 110s to the lowest power setting Switches 1 2 and 3 in the ON position and observe the SIGNAL OK LED on the rear panel of the other GPIB 110 unit 3 Increase the transmit power by changing the switches until the SIGNAL OK LED lights up on the other GPIB 110 Then increase the power setting by one 4 Setthe transmit power switches on the other GPIB 110 to the same configuration National Instruments Corporation 2 7 GPIB 110 User Manual Configuration and Installation Chapter 2 Transmit Clock The GPIB 110 has a variable transmit frequency that must be set for a given length of fiber optic or coaxial cable If you are using fiber optic cable set the transmit clock to 10 MHz for any length
61. ssary to use this mode to operate the GPIB 110s Note The self test switch settings are reversed from the markings that appear on the switch To set your GPIB 110 for self test mode you must set the switch in the OFF position National Instruments Corporation 2 11 GPIB 110 User Manual Configuration and Installation Chapter 2 Self Test with Coaxial Cable Use the following steps to run the Self Test mode with the coaxial cable 1 Turn the GPIB 110 power switch to OFF 2 Disconnect the coaxial cable from the rear panel connector 3 Setthe master switch to the ON position Switch 6 OFF and the self test switch to the ON position Switch 4 OFF 4 Turn the GPIB 110 power switch to ON At this point the LINK LED on the front panel lights up indicating that the Self Test mode is operating correctly In addition the ERR LED remains off Note Be sure to turn the self test switch to the OFF position Switch 4 ON and the master switch to the original position and reconnect the coaxial cable before re using the GPIB 110 Self Test with Fiber Optic Cable To run the Self Test mode with the fiber optic cable you must connect a single fiber optic cable in a loop from the transmit output to the receive input of the GPIB 110 You can use the opposite ends of the extension cable or purchase a short loopback cable from National Instruments Use the following steps to run the Self Test mode with the fiber optic cable 1 Turn th
62. ssion Transmit Data FO Transmit Link Power Establishment Active Controller Detection Source Handshake Detection and Handshake Control Data Direction Parallel Poll Control Control System Clock Transmission Synchronization and Timing GPIB State Sampling Parallel To Serial Conversion Fiber Optic Transmitter and Receiver GPIB Transceivers Error Detection and Recovery Packet Reception Parallel Poll Response Register GPIB Transceivers Packet Reception Decoding Timing Receive Data Serial To Parallel Conversion Multiplexer Transmitter and Receiver Communication Extension muni Circuitry Circuitry Figure 3 1 GPIB 110 Block Diagram Extension Circuitry The extension circuitry converts signals received from the local GPIB to the X signals as shown in Figure 3 1 and drives the R signals onto the local GPIB The X signals sent from one GPIB 110 unit after serialization and transmission become the R signals on the remote GPIB 110 unit after being received and converted back into parallel form The System Controller Active Controller and Source Handshake states on the GPIB 110 unit determine which GPIB signals are sensed and or driven Power On When the GPIB 110 is turned on a reset pulse clears all circuitry to an initialized state The units then begin executing the link establishment protocol which is discussed in the Link Establishment Protocol section later in this chapter
63. t the connector marked T to the fiber optic connector marked TRANS on the GPIB 110 rear panel Connect the connector marked R to the fiber optic connector marked RCVR on the GPIB 110 rear panel The connectors are connected by pushing the cable connector gently into the rear panel connector and screwing the cable connector onto the rear panel connector securely When fiber optic cable is used Switch 4 on the rear panel configuration switch must be set to the ON Self Test mode OFF position and Switches 1 through 3 and 5 through 10 must be configured as explained in the following sections Refer to Figure 2 3 for the default settings and to Figure 2 4 for configuration options for fiber optic cable setup Master Switch Setting The operation of the GPIB 110 requires one of the connected pairs of GPIB 110s to be configured as the master The master GPIB 110 is the one that initiates communication between the GPIB 110s Either side can be the master On one of the GPIB 110s set Switch 6 to the ON position Set Switch 6 of the other GPIB 110 to the OFF position The GPIB 110 with the master switch set in the OFF position is master Note The master switch settings are reversed from the markings that appear on the switch To set your GPIB 110 as master you must set the switch in the OFF position Fiber Optic Transmit Power The Fiber Optic Transmit Power settings apply only to the GPIB 110 models using fiber optic cable The Fiber Optic Tran
64. the handshake to continue At this point the unit drives the NRFD and NDAC lines according to the levels sensed at the remote unit and received as R RFD and R DAC Parallel Polling When the GPIB 110 detects ATN and EOI simultaneously asserted on the local bus the Parallel Poll In Progress state becomes true and X EOI is transmitted to the remote side along with X ATN X EOI and X ATN continue to be propagated to the remote side until a Parallel Poll Response is returned from the remote unit even if the local ATN and EOI signals become false NRED is asserted on the local bus during the Parallel Poll If the latched Parallel Poll Response PPR mode is selected the contents of the PPR register are driven onto the local GPIB DIO lines Otherwise the local GPIB DIO lines are driven passively false until a packet is received from the remote unit containing the Parallel Poll Response The GPIB DIO lines are then driven with the response byte when it is received GPIB 110 User Manual 3 4 National Instruments Corporation Chapter 3 Theory of Operation X EOI and X ATN are received on the remote side as R EOI and R ATN and propagated to the GPIB Two microseconds later the Parallel Poll Response on the remote side GPIB is sampled and returned as the Parallel Poll Response to the local unit When the Parallel Poll Response is received by the local unit the Parallel Poll Response byte is driven onto the GPIB DIO lines if the GPIB 110 is not in l
65. the local unit is conducting a Parallel Poll or if the RS state is true and the local unit is not conducting a Parallel Poll SRQ The local GPIB unit transmits X SRQ to the remote unit if the location of the Active Controller has not been detected The remote unit drives the local bus according to the value of R SRQ received When the location of the Active Controller has been detected SRQ is sent to the remote unit only if the Active Controller is on the remote unit side National Instruments Corporation 3 5 GPIB 110 User Manual Theory of Operation Chapter 5 Serial Communication Circuitry The GPIB 110 units connected via a serial link maintain their communication through the use of digital packets The serial communication circuitry is responsible for converting packets from parallel to serial form for transmission and back to parallel form after reception The circuitry also maintains continuous communication between the extenders and is responsible for packet error detection and recovery Link Establishment Protocol The two GPIB 110s use a protocol in which each extender transmits a packet as soon as a packet is received In this way communication between the extenders is continuous The LINK LED on the GPIB 110 front panel lights up when the unit is receiving error free packets from the remote unit When you power on the master GPIB 110 transmits a packet to the remote unit and waits approximately 30 us for a packet to be
66. tigura on i ciu atia Dar MR qct o diced 2 5 Figure 2 4 GPIB sO Label ie nn enata 2 5 Figure 2 5 Internal Cable Selection Jumper Shown for Coaxial Cable 2 6 Figure 3 1 GPIB 110 Block Diagramme 3 2 Figure GPIB Cable Connector nent engine C3 Figure C 2 Linear Configuration of the GPIB Devices C 5 Figure C 3 Star Configuration of GPIB Devices C 6 Tables Table 2 1 Transmit Clock Values Versus Cable 2 8 Table A 1 Performance Versus Distance unsere de tee t tetti da te Peta a etes 1 Table A 2 Electrical Specifications sui n erp ete fans pente ete dee Eae ee A 3 GPIB 110 User Manual vii National Instruments Corporation About This Manual The GPIB 110 User Manual describes how to install configure and operate the GPIB 110 The GPIB 110 is a high performance bus extender that converts IEEE 488 signals into data packets for transmission to a matching GPIB 110 using a serial communication link to the distant extender The receiving extender converts the packets back to IEEE 488 signals Organization of This Manual This manual is organized as follows Chapter 1 Description of the GPIB 110 contains general information about the National Instruments GPIB 110 lists the contents of the GPIB 110 kit and explains how to unpack the GPIB 110 kit Chapter 2 Configuration and Installation co
67. ts available GPIB cable National Instruments part number 763061 xx or equivalent Transmission cable Belden V P C part number 95680 75 Q coaxial cable 9248 RG 6 U type with male BNC connectors Optical Cable Corporation fiber optic cable A02 030D C4DB 900 3 mm cable diameter Flame retardant PVC jacket Graded 100 140 micron core clad with a minimum NA of 0 28 850 nm operating wavelength 4 dB km attenuation 100 MHz km fiber bandwidth Duplex style terminated with aluminum SMA style connectors National Instruments Corporation A 3 GPIB 110 User Manual Appendix B Multiline Interface Messages This appendix lists the multiline interface messages and describes the mnemonics and messages that correspond to the interface functions These functions include initializing the bus addressing and unaddressing devices and setting device modes for local or remote programming The multiline interface messages are IEEE 488 defined commands that are sent and received with ATN TRUE For more information on these messages refer to the ANSI IEEE Standard 488 1987 IEEE Standard Digital Interface for Programmable Instrumentation National Instruments Corporation B 1 GPIB 110 User Manual Multiline Interface Messages Message Definitions DCL GET GTL LLO MLA Oct Dec 000 0 001 1 002 2 003 3 004 4 005 5 006 6 007 7 010 8 011 9 012 10 013 11 014 12 015 13 016 14 017 15 020 16 021 17 022 18 023 19 024 20
68. ws the label on the bottom of the GPIB 110 CONFIGURATION forF irc OFF Jon MASTER ON LATCHED POLL OFF EI FO TRANSMIT SELFTEST ON NATIONAL INSTRUMENTS COPYRIGHT 1985 Sw No TRANSMIT sw No TRANSMIT POWER 10 CLOCK 100 87 5 75 62 5 50 37 5 25 12 5 1 7 8 2 31 2 125 2 500 2 1 MHz 2 MHz 5 MHz 10 MHz 1 1 0 0 0 0 1 1 1 1 0 Oo l2 oooo c o alo Figure 2 4 GPIB 110 Label Place the GPIB 110s in close proximity and connect the cable to be used to each unit National Instruments Corporation 2 5 GPIB 110 User Manual Configuration and Installation Chapter 2 Cable Selection The GPIB 110 is shipped with either a coaxial or fiber optic cable and with the cable selection jumper set according to the model number However if you have to change the type of cable you are using you must also change the jumper setting located on the inside of the GPIB 110 as shown in Figure 2 5 See Figure 2 1 letter b for the location of this jumper RCV XMIT Figure 2 5 Internal Cable Selection Jumper Shown for Coaxial Cable Use the following steps to change the setting of the cable selection jumper Warning Hazardous voltage inside Remove power cord before opening unit Turn the power switch to OFF This switch is located on the rear panel of the GPIB 110 2 Disconnect the power c

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