National Instruments Corporation GPIB-1014P User manual

© Copyright 1984, 1994 National Instruments Corporation.
All Rights Reserved.
GPIB-1014P
User Manual
June 1994 Edition
Part Number 370944A-01

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Limited Warranty
The GPIB-1014P 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 document has been carefully
reviewed for technical accuracy. In the event that technical or typographical errors exist, National Instruments
reserves the right to make changes to subsequent editions of this document without prior notice to holders of this
edition. The reader should consult National Instruments if errors are suspected. In no event shall National
Instruments be liable for any damages arising out of or related to this document or the information contained in it.
EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED,
AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. CUSTOMER’S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART
OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER.
NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS,
USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY
THEREOF. This limitation of the liability of National Instruments will apply regardless of the form of action,
whether in contract or tort, including negligence. Any action against National Instruments must be brought within
one year after the cause of action accrues. National Instruments shall not be liable for any delay in performance due
to causes beyond its reasonable control. The warranty provided herein does not cover damages, defects,
malfunctions, or service failures caused by owner’s failure to follow the National Instruments installation, operation,
or maintenance instructions; owner’s modification of the product; owner’s abuse, misuse, or negligent acts; and
power failure or surges, fire, flood, accident, actions of third parties, or other events outside reasonable control.
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Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or
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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 appropriate in the particular situation to prevent
serious injury or death should always continue to be used when National Instruments products are being used.
National Instruments products are NOT intended to be a substitute for any form of established process, procedure, or
equipment used to monitor or safeguard human health and safety in medical or clinical treatment.

FCC/DOC Radio Frequency Interference Compliance
This equipment generates and uses radio frequency energy and, if not installed and used in strict accordance with the
instructions in this manual, may cause interference to radio and television reception. This equipment has been tested
and found to comply with the following two regulatory agencies:
Federal Communications Commission
This device complies with Part 15 of the Federal Communications Commission (FCC) Rules for a Class A digital
device. Operation is subject to the following two conditions:
1. This device may not cause harmful interference in commercial environments.
2. This device must accept any interference received, including interference that may cause undesired operation.
Canadian Department of 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 présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils
numériques de classe A prescrites dans le règlement sur le brouillage radioélectrique édicté par le ministère 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.
• Operate the equipment and the receiver on different branches of your AC electrical system.
• Move the equipment away from the receiver with which it is interfering.
• Reorient or relocate the receiver’s antenna.
• Be sure that the equipment is plugged into a grounded outlet and that the grounding has not been defeated with
a cheater plug.
Notice to user: Changes or modifications not expressly approved by National Instruments could void the user’s
authority to operate the equipment under the FCC Rules.
If necessary, consult National Instruments or an experienced radio/television technician for additional suggestions.
The following booklet prepared by the FCC may also be helpful: How to Identify and Resolve Radio-TV
Interference Problems. This booklet is available from the U.S. Government Printing Office, Washington, DC
20402, Stock Number 004-000-00345-4.

© National Instruments Corporation v GPIB-1014P User Manual
Preface
The GPIB-1014P is a single-height circuit board which interfaces the VMEbus to the IEEE-488
General Purpose Interface Bus (GPIB). The GPIB-1014P provides a means to implement
VMEbus test and measurement systems with standard interconnecting cables.
Organization of the Manual
This manual describes the mechanical and electrical aspects of the GPIB-1014P and contains
information concerning its operation and programming. The manual is divided into the following
sections:
• Section One, General Information, describes the GPIB-1014P, lists the contents of your
GPIB-1014P kit, and explains how to unpack the GPIB-1014P kit.
• Section Two, General Description, contains the physical and electrical specifications for the
GPIB-1014P and describes the characteristics of key interface board components.
• Section Three, Configuration and Installation, describes the steps needed to configure the
GPIB-1014P hardware and to verify that it is functioning properly.
• Section Four, Register Bit Descriptions, contains detailed descriptions of the GPIB Interface
registers of the NEC µPD7210 LSI GPIB Talker/Listener/Controller as well as summary
tables for easy reference.
• Section Five, Programming Considerations, explains important considerations for
programming the GPIB-1014P.
• Section Six, Theory of Operation, contains a functional overview of the GPIB-1014P board
and explains the operation of each functional block making up the GPIB-1014P.
• Section Seven, GPIB-1014P Diagnostic and Troubleshooting Test Procedures, contains test
procedures for determining if the GPIB-1014P is installed and operating correctly.
• Appendix A, Specifications, lists the specifications of the GPIB-1014P.
• Appendix B, Parts List and Schematic Diagrams, contains a parts list and detailed schematic
diagrams.
• Appendix C, Sample Programs, provides sample programs in 68000 Assembly Language
code for implementing the most commonly used GPIB functions. Line-by-line comments
provide an explanation of each function.
• Appendix D, Multiline Interface Command Messages, contains a listing of the multiline GPIB
interface messages.

Preface
GPIB-1014P User Manual vi © National Instruments Corporation
• Appendix E, Operation of the GPIB, describes the operation of the GPIB.
• Appendix F, Mnemonics Key, contains an alphabetical listing of all mnemonics used in this
manual and indicates whether the mnemonic represents a bit, register, function, remote
message, local message, state, VMEbus operation, or VMEbus signal.
• Appendix G, Customer Communication, contains forms you can use to request help from
National Instruments or to comment on our products and manuals.
• The Index contains an alphabetical list of key terms and topics in this manual, including the
page where you can find each one.
Abbreviations Used in This Manual
The following abbreviations are used in the text of this manual.
A ampere
C Celsius
°degree
hex hexadecimal
in. inch
kbytes 1000 bytes
m meter
Mbytes million bytes
mm millimeter
MHz megahertz
µsec microsecond
nsec nanosecond
sec second
V volt
VDC volts direct current

Preface
© National Instruments Corporation vii GPIB-1014P User Manual
Related Documents
The following manuals provide information that may be helpful as you read this manual:
• ANSI/IEEE Std. 488-1978, IEEE Standard Digital Interface for Programmable
Instrumentation
• ANSI/IEEE Std. 1014-1987, IEEE Standard for a Versatile Backplane Bus: VMEbus
•
µ PD7210 GPIB-IFC User Manual
•
µ PD7210 Intelligent GPIB Interface Controller Engineering Data Sheet
•How to Interface a Microcomputer System to a GPIB (& The NEC µPD7210 TLC)
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 G, Customer
Communication, at the end of this manual.

© National Instruments Corporation xi GPIB-1014P User Manual
Contents
Section One
General Information ........................................................................................................1-1
What Your Kit Should Contain .....................................................................................1-3
Optional Equipment ......................................................................................................1-3
Unpacking .....................................................................................................................1-3
Section Two
General Description ..........................................................................................................2-1
Physical Characteristics ................................................................................................2-1
Electrical Characteristics ...............................................................................................2-1
VMEbus Characteristics ...............................................................................................2-2
VMEbus Slave-Addressing ...............................................................................2-2
VMEbus Slave-Data .........................................................................................2-3
Interrupter ..........................................................................................................2-4
VMEbus Modules Not Provided .......................................................................2-5
Diagnostic Aids .................................................................................................2-5
Data Transfer Features ..................................................................................................2-5
GPIB-1014P Functional Description ............................................................................2-5
Section Three
Configuration and Installation ....................................................................................3-1
Configuration ................................................................................................................3-1
Access Mode .....................................................................................................3-3
VMEbus Base Address .....................................................................................3-3
VMEbus Interrupt Configuration ......................................................................3-5
Interrupt Request Line Selection ........................................................... 3-5
Interrupt Priority Code ..........................................................................3-5
Interrupt Status/ID Vector Selection .................................................................3-7
GPIB Cable Shield Grounding ..........................................................................3-8
Installation .....................................................................................................................3-9
Verification of System Compatibility ...............................................................3-9
Verification Testing ..........................................................................................3-10
Cabling ..............................................................................................................3-10
Section Four
Register Bit Descriptions ................................................................................................4-1
Register Map .................................................................................................................4-1
Register Sizes ....................................................................................................4-2
Register Description Format .................................................................4-2
Terminology ..........................................................................................4-2
Interface Registers .........................................................................................................4-3
Data In Register (DIR) ......................................................................................4-6
Command/Data Out Register (CDOR) .............................................................4-7
Interrupt Status Register 1 (ISR1) .....................................................................4-8
Interrupt Mask Register 1 (IMR1) ....................................................................4-8

Contents
GPIB-1014P User Manual xii © National Instruments Corporation
Interrupt Status Register 2 (ISR2) .....................................................................4-14
Interrupt Mask Register 2 (IMR2) ....................................................................4-14
Serial Poll Status Register (SPSR) ....................................................................4-19
Serial Poll Mode Register (SPMR) ...................................................................4-19
Address Status Register (ADSR) ......................................................................4-20
Address Mode Register (ADMR) .....................................................................4-22
Command Pass Through Register (CPTR) .......................................................4-25
Auxiliary Mode Register (AUXMR) ................................................................4-27
Hidden Registers ...............................................................................................4-34
Internal Counter Register (ICR) ............................................................4-35
Parallel Poll Register (PPR) ..................................................................4-36
Auxiliary Register A (AUXRA) ...........................................................4-38
Auxiliary Register B (AUXRB) ............................................................4-40
Auxiliary Register E (AUXRE) ............................................................4-42
Address Register 0 (ADR0) ..............................................................................4-43
Address Register (ADR) ...................................................................................4-44
Address Register 1 (ADR1) ..............................................................................4-45
End Of String Register (EOSR) ........................................................................4-46
Section Five
Programming Considerations .......................................................................................5-1
Initialization ..................................................................................................................5-1
The GPIB-1014P as GPIB Controller ...........................................................................5-2
Becoming Controller-In-Charge (CIC) and Active Controller .........................5-2
Sending Remote Multiline Messages (Commands) ..........................................5-3
Going from Active to Standby Controller ......................................................... 5-3
Going from Standby to Active Controller ......................................................... 5-4
Going from Active to Idle Controller ...............................................................5-4
The GPIB-1014P as GPIB Talker and Listener ............................................................5-5
Programmed Implementation of Talker and Listener .......................................5-5
Addressed Implementation of the Talker and Listener .....................................5-5
Address Mode 1 ....................................................................................5-5
Address Mode 2 ....................................................................................5-5
Address Mode 3 ....................................................................................5-6
Sending/Receiving Messages ........................................................................................5-7
Sending/Receiving END or EOS ......................................................................5-7
Interrupts .......................................................................................................................5-7
Serial Polls ....................................................................................................................5-8
Conducting Serial Polls .....................................................................................5-8
Responding to a Serial Poll ...............................................................................5-8
Parallel Polls .................................................................................................................5-9
Conducting a Parallel Poll ................................................................................. 5-9
Responding To a Parallel Poll ...........................................................................5-10
Section Six
Theory of Operation ........................................................................................................6-1
VMEbus Interface .........................................................................................................6-1
Data Lines .........................................................................................................6-1
Control Signals ..................................................................................................6-1
Address Lines ....................................................................................................6-2

Contents
© National Instruments Corporation xiii GPIB-1014P User Manual
Address Decoding .........................................................................................................6-2
Clock and Reset Circuitry .............................................................................................6-2
Timing Control Logic ...................................................................................................6-3
Interrupter Logic ...........................................................................................................6-3
GPIB Interface ..............................................................................................................6-4
Test and Troubleshooting .............................................................................................. 6-5
Section Seven
GPIB-1014P Diagnostic and Troubleshooting Test Procedures .....................7-1
Interpreting Test Procedures .........................................................................................7-1
GPIB-1014P Hardware Installation Tests .....................................................................7-2
Appendix A
Specifications .......................................................................................................................A-1
Appendix B
Parts List and Schematic Diagrams ...........................................................................B-1
Appendix C
Sample Programs ...............................................................................................................C-1
Appendix D
Multiline Interface Command Messages ..................................................................D-1
Appendix E
Operation of the GPIB ....................................................................................................E-1
Types of Messages ........................................................................................................E-1
Talkers, Listeners, and Controllers ...............................................................................E-1
The Controller-In-Charge and System Controller ........................................................E-2
GPIB Signals and Lines ................................................................................................E-2
Data Lines .........................................................................................................E-2
Handshake Lines ...............................................................................................E-2
NRFD (not ready for data) ....................................................................E-2
NDAC (not data accepted) ....................................................................E-2
DAV (data valid) ...................................................................................E-3
Interface Management Lines .............................................................................E-3
ATN (attention) .....................................................................................E-3
IFC (interface clear) ..............................................................................E-3
REN (remote enable) ............................................................................E-3
SRQ (service request) ...........................................................................E-3
EOI (end or identify) .............................................................................E-3
Physical and Electrical Characteristics .........................................................................E-3
Configuration Requirements .........................................................................................E-6
Related Document .........................................................................................................E-7
Appendix F
Mnemonics Key ..................................................................................................................F-1

Contents
GPIB-1014P User Manual xiv © National Instruments Corporation
Appendix G
Customer Communication...............................................................................................G-1
Index..................................................................................................................................Index-1
Figures
Figure 1-1. GPIB-1014P Interface Board ...............................................................................1-2
Figure 2-1. GPIB-1014P with a VMEbus Computer ..............................................................2-6
Figure 2-2. GPIB-1014P in a Multiprocessor Application .....................................................2-7
Figure 2-3. GPIB-1014P Block Diagram ...............................................................................2-8
Figure 3-1. GPIB-1014P Parts Locator Diagram .................................................................... 3-2
Figure 3-2. Access Selection .................................................................................................. 3-3
Figure 3-3. Configuration for VMEbus Base Address 1000 hex (default setting) .................3-4
Figure 3-4. VMEbus Interrupt Line Selection ........................................................................3-5
Figure 3-5. VMEbus Interrupt Priority Code Selection ..........................................................3-6
Figure 3-6. Status/ID Byte 1A hex .........................................................................................3-7
Figure 3-7. GPIB Cable Shield Grounding .............................................................................3-8
Figure 3-8. GPIB Cable Connector ......................................................................................... 3-11
Figure 4-1. µPD7210 Interface Registers ...............................................................................4-4
Figure 4-2. Writing to the Hidden Registers ........................................................................... 4-5
Figure E-1. GPIB Connector and the Signal Assignment ....................................................... E-4
Figure E-2. Linear Configuration ............................................................................................ E-5
Figure E-3. Star Configuration ................................................................................................ E-6
Tables
Table 2-1. GPIB-1014P Signals ............................................................................................2-1
Table 2-2. µPD7210 Internal GPIB Interface Registers ........................................................2-3
Table 2-3. GPIB-1014P IEEE-488 Interface Capabilities .....................................................2-10
Table 2-4. GPIB-1014P IEEE-1014 Interrupter Compliance Levels ....................................2-12
Table 3-1. GPIB-1014P Pin Assignment on VMEbus Connector P1 ...................................3-9
Table 4-1. GPIB-1014P Register Map ..................................................................................4-1
Table 4-2. Clues to Understanding Mnemonics ....................................................................4-3
Table 4-3. Multiline GPIB Commands Recognized by the µPD7210...................................4-25
Table 4-4. Auxiliary Command Summary ............................................................................4-28
Table 4-5. Auxiliary Commands Detail Description .............................................................4-30

© National Instruments Corporation 1-1 GPIB-1014P User Manual
Section One
General Information
The GPIB-1014P is an IEEE-488 interface for the VMEbus. This interface permits IEEE-488
compatible engineering, scientific, or medical instruments to be controlled from a VMEbus-based
computer. The GPIB-1014P has the following features:
• Complete IEEE-488 Talker/Listener/Controller (TLC) capability using the NECµPD7210
GPIB TLC chip
• Polled or interrupt driven transfers
• Transfer rates up to 80 kbytes/sec
• User configurable parameters
- Base Address
- Interrupt Request Line
- Interrupt Status/ID byte
- Supervisor or User Access
• IEEE-1014 (VMEbus) standard compliance
• Comprehensive software support
The GPIB-1014P conforms to all requirements and conventions specified in the ANSI/IEEE Std.
1014-1987. Hereafter, the General Purpose Interface Bus is referred to as the GPIB, the GPIB
standard is referred to as the IEEE-488 standard, and the ANSI/IEEE Std. 1014-1987 is referred
to as the IEEE-1014 standard.

Section One General Information
© National Instruments Corporation 1-3 GPIB-1014P User Manual
What Your Kit Should Contain
Your GPIB-1014P kit contains one of the following boards:
• GPIB-1014P-1
• GPIB-1014P-2
• GPIB-1014P-1S
Optional Equipment
You can contact National Instruments to order the following optional equipment:
• Single-shielded Type X1 GPIB cables* (1 m, 2 m, 4 m, or 8 m)
• Double-shielded Type X2 GPIB cables* (1 m, 2 m, or 4 m)
* To meet FCC emission limits for this Class A device, you must use a shielded
(Type X1 or X2) GPIB cable. Operating this equipment with a non-shielded cable
may cause interference to radio and television reception in commercial areas.
• GPIB Monitor/Analyzer
– GPIB-400
– GPIB-410
Unpacking
Follow these steps when unpacking your GPIB-1014P:
1. Your GPIB-1014P board is shipped packaged in an antistatic plastic bag to prevent electrostatic
damage to the board. Several components on the board can be damaged by electrostatic
discharge. To avoid such damage in handling the board, touch the plastic bag to a metal part of
your VMEbus computer chassis before removing the board from the bag.
2. Remove the board from the bag and inspect the board for loose components or any other sign
of damage. Notify National Instruments if the board appears damaged in any way. DO NOT
install a damaged board into your computer.

© National Instruments Corporation 2-1 GPIB-1014P User Manual
Section Two
General Description
This section contains the physical and electrical specifications for the GPIB-1014P and describes
the characteristics of key interface board components, including a functional block diagram as well
as illustrations of applications in test and measurement configurations.
Physical Characteristics
The GPIB-1014P measures 160 by 100 mm and is supplied with a standard 24-pin GPIB
connector mounted on the front panel. The card is available with both single- and double-height
metal front panels (.8 in. width). A DIN 41612 96-pin connector connects the GPIB-1014P to the
VMEbus backplane.
Electrical Characteristics
All integrated circuit drivers and receivers used on the GPIB-1014P meet the requirements of the
VMEbus Specification and the IEEE-1014 standard. Table 2-1 contains a list of the VMEbus
signals used by the GPIB-1014P and the device used to interface to each signal.
Note: The asterisk (*) after the bus signal indicates the signal is active low.
Table 2-1. GPIB-1014P Signals
Driver Device Receiver Device
Bus Signals Part Number Part Number
D00-D07 F245 F245
A15-A04 LS2521
AM4-AM3,AM0,AM1 LS2521
DS0*,WRITE*,IACK*,IACKIN*, LS240
SYSRESET*, SYSCLK*
LWORD*,AM5,AM2 F20
(continues)

General Description Section Two
GPIB-1014P User Manual 2-2 © National Instruments Corporation
Table 2-1. GPIB-1014P Signals (continued)
Driver Device Receiver Device
Bus Signals Part Number Part Number
DTACK* F38 LS240
IACKOUT* F20 –
IRQ1*through IRQ7* F38 –
AS*,DS1*,WRITE* – ALS244
A03 through A01 – ALS244
The GPIB transceivers meet the requirements of the IEEE-488 standard. The components used
are as follows:
Transceivers Component Designation
Data Transceivers 75160
Control Transceivers 75162
Note: Current load is typically 0.5 A (1 A maximum).
VMEbus Characteristics
The following paragraphs describe both modules on the GPIB-1014P: slave and interrupter.
Table 2-3 later in this section summarizes the capabilities of these modules.
VMEbus Slave-Addressing
The GPIB-1014P occupies 16 bytes of consecutive memory addresses located in the A16 (short)
Input/Output (I/O) space. These addresses are used to access the GPIB Talker/Listener/Controller
(TLC). As a VMEbus slave, it only responds when the address modifier (AM) lines specify a
short supervisory access (AM code = 2D) or short non-privileged access (AM code = 29). An
onboard jumper allows selection of privileged or non-privileged access to the board.
The board responds to 16-bit addresses. It compares address lines A04 through A15 with its
hardware-programmable base address (see Base Address in Section Three) to generate its board
select signal. The Talker/Listener/Controller (TLC) decodes the remaining address lines, A01
through A03, and the data strobe DSO* into eight memory-mapped interface register addresses.
The GPIB TLC (µPD7210) interface registers are addressed relative to the base address of the
board as shown in Table 2-2.

Section Two General Description
© National Instruments Corporation 2-3 GPIB-1014P User Manual
Table 2-2. µPD7210 Internal GPIB Interface Registers
Address (Base
+ Hex Offset) Mode Register Size
1 R Data In (DIR) 8 bits
1 W Control/Data Out (CDOR) 8 bits
3 R Interrupt Status 1 (ISR1) 8 bits
3 W Interrupt Mask 1 (IMR1) 8 bits
5 R Interrupt Status 2 (ISR2) 8 bits
5 W Interrupt Mask 2 (IMR2) 8 bits
7 R Serial Poll Status (SPSR) 8 bits
7 W Serial Poll Mode (SPMR) 8 bits
9 R Address Status (ADSR) 8 bits
9 W Address Mode (ADMR) 8 bits
B R Command Pass Through (CPTR) 8 bits
B W Auxiliary Mode (AUXMR) 8 bits
D R Address 0 (ADR0) 8 bits
D W Address (ADR) 8 bits
F R Address 1 (ADR1) 8 bits
F W End of String (EOSR) 8 bits
VMEbus Slave-Data
As discussed previously, the GPIB-1014P can function as a VMEbus slave, decoding memory
addresses and commands from a VMEbus master. It is designed to accommodate address
pipelining as well as Address Only (ADO) cycles. All data is transferred to and from the
VMEbus with lines D00 through D07. In VMEbus terminology, the slave module of the board is
designated as A16/D08(0). The board does not implement Unaligned Transfer (UAT), Block
Transfer (BLT), and Read-Modify-Write (RMW) cycles.

General Description Section Two
GPIB-1014P User Manual 2-4 © National Instruments Corporation
Interrupter
Interrupt events that originate from the TLC are as follows:
• GPIB Data In (DI)
• GPIB Data Out (DO)
• END message received (END RX)
• GPIB Command Out (CO)
• Remote mode change (REMC)
• GPIB handshake error (ERR)
• Lockout change (LOKC)
• Address Status Change (ADSC)
• Secondary Address received (APT)
• Service Request received (SRQI)
• Trigger command received (DET)
• Device Clear received (DEC RX)
• Unrecognized Command received (CPT)
All 13 interrupt events are wire-ORed in the TLC to a single signal designated INT on the interface
board. When one of these events occurs, INT goes high and one of the interrupt request lines
(IRQ1* through IRQ7*) is driven low. You select the interrupt request line by means of an
onboard jumper. You set the interrupt priority via three hardware switches (U28). The encoded
value of the priority must match the level of the interrupt request line. See Interrupt Request Line
Selection in Section Three for more information on setting the interrupt level.
The onboard hardware implements the VMEbus interrupt acknowledge protocol. The interrupter
drives the VMEbus with an 8-bit Status/ID byte (vector) during an interrupt acknowledge cycle.
This Status/ID byte is set by an onboard 8-position Dual In-line Package (DIP) switch (U7). After
the interrupt handler reads the Status/ID byte from the data bus, it releases the data strobe DS0* to
high. Upon seeing DS0* high, the interrupter releases the data bus and the interrupt request line.
This implies that the GPIB-1014P interrupter is a Release On Acknowledge (ROAK) interrupter.
Note: Even though the interrupt request line is no longer driven, the TLC Interrupt (INT) line
remains asserted until it is cleared in the interrupt service routine by reading the appropriate
status register (ISR1 or ISR2). Clearing the TLC INT line in the interrupt routine enables
further interrupts from the GPIB-1014P.

Section Two General Description
© National Instruments Corporation 2-5 GPIB-1014P User Manual
VMEbus Modules Not Provided
Because the GPIB-1014P is not designed to be VMEbus System Controller, it does not have the
following modules:
• Master
• Bus Timer
• Arbiter
• Interrupt Handler
• IACK Daisy Chain Driver
• System Clock Driver
• Serial Clock Driver
• Power Monitor
Diagnostic Aids
The GPIB-1014P is designed to allow stand-alone verification of I/O functions. See Section
Seven, GPIB-1014P Diagnostic and Troubleshooting Test Procedures, for details.
Data Transfer Features
The GPIB-1014P can be used to transfer data to and from the GPIB using programmed I/O.
Typical transfer rates range from 10 to 80 kbytes/sec. Data transfer rates approaching 1 Mbyte/sec
can be obtained with very high performance microprocessors and driver software. The actual
transfer rate for any particular GPIB system is a function of several factors including the
following:
• Response time of the GPIB devices involved
• Microprocessor speed and operating system and application program overhead
• Interrupt service response time
GPIB-1014P Functional Description
In the simplest terms, the GPIB-1014P can be thought of as a bus translator, converting messages
and signals present on the VMEbus into appropriate GPIB messages and signals. Expressed in
GPIB terminology, the GPIB-1014P implements GPIB interface functions for communicating
with other GPIB devices and device functions for communicating with the central processor and
memory. Expressed in VMEbus terminology, the GPIB-1014P is an interface to the outside
world.

General Description Section Two
GPIB-1014P User Manual 2-6 © National Instruments Corporation
Figure 2-1 and Figure 2-2 show typical applications for the GPIB-1014P. In Figure 2-2, the
GPIB-1014P is used to interface an assortment of test instruments to a VMEbus computer
system, which then functions as an intelligent System Controller. This is the traditional role of the
GPIB.
In Figure 2-2, the GPIB-1014P is used along with other National Instruments interface boards to
connect a VMEbus computer to other processors in order to transfer information or to perform
other communication functions.
3 Lines
Digital
Voltmeter
Able to Talk
and Listen
Device C
Printer
Able to Listen
Device B
Device A
VMEbus Computer with GPIB-1014P
Able to Talk, Listen, and Control
8 Lines
5 Lines
DIO1-DIO8
DAV (Data Valid)
NRFD (Not Ready for Data)
NDAC (Not Data Accepted)
IFC (Interface Clear)
ATN (Attention)
SRQ (Service Request)
REN (Remote Enable)
EOI (End or Identify)
Data Lines
Handshake Lines
Management Lines
Frequency
Counter
Able to Talk
Figure 2-1. GPIB-1014P with a VMEbus Computer