National Instruments GPIB-120B User Manual

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GPIB

GPIB-120B User Manual

February 2019 371851C-01

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Page 6

Contents

About This Manual

Related Documentation .................................................................................................... ix

Chapter 1 Introduction

Description of the GPIB-120B ......................................................................................... 1-1

What You Need to Get Started ......................................................................................... 1-3

Optional Equipment.................................................................................................. 1-3

Unpacking Your GPIB-120B ................................................................................... 1-4

Chapter 2 Hardware Overview

GPIB-120B LEDs............................................................................................................. 2-1

Power On (PWR)...................................................................................................... 2-1

System Controller Detection (SC) ............................................................................ 2-1

Active Controller Detection (AC) ............................................................................ 2-1

Source Handshake Detection (SH) ........................................................................... 2-2

Data Transfer Modes ........................................................................................................ 2-2

Selecting a Data Transfer Mode ............................................................................... 2-2

Unbuffered Mode ............................................................................................. 2-2

Buffered Mode.................................................................................................. 2-2

Setting the Data Transfer Mode................................................................................ 2-3

Data Direction Control ..................................................................................................... 2-3

Parallel Poll Detection ...................................................................................................... 2-3

Parallel Poll Operation...................................................................................................... 2-4

Chapter 3 Configuring and Using Your Hardware

Connecting the GPIB-120B.............................................................................................. 3-1

Appendix A GPIB Basics

Appendix B Multiline Interface Messages

Appendix C Specifications

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Contents

Appendix D NI Services

Index

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Page 8

About This Manual

This manual describes how to install, configure, and operate the National Instruments GPIB-120B.

Related Documentation

The following documents contain information that you may find helpful as you read this manual:

• ANSI/IEEE Standard 488.1-1987, IEEE Standard Digital Interface for Programmable

Instrumentation

• ANSI/IEEE Standard 488.2-1992, IEEE Standard Codes, Formats, Protocols, and

Common Command

Page 9

Introduction

This chapter contains a description of the GPIB-120B, lists what you need to get started and optional equipment you can order, and explains how to unpack the GPIB-120B.

Description of the GPIB-120B

The GPIB-120B is a high-speed bus isolator/expander with the following features:

• It is transparent to user software.

• It electrically isolates two GPIB systems from each other and from the power supply.

• It expands the GPIB to interface up to 28 devices.

• It extends the GPIB by effectively doubling the 20 m cable limit.

• It has optional rack or DIN rail mount hardware accessories.

The high-speed GPIB-120B bus isolator/expander connects two GPIB (IEEE 488) bus systems in a functionally transparent manner.

The two bus systems are electrically isolated from each other. The two bus systems are also isolated from the power supply. Isolation is maintained up to 2500 VDC (withstand 5 s). Isolating an instrument or group of instruments from an IEEE 488 bus Controller can eliminate ground loop noise and induced common-mode noise, which may cause measurement problems in both analog and digital systems. The two isolated bus systems are physically separate, as shown in Figure 1-1; however, the devices logically appear to be on the same bus, as shown in Figure 1-2.

Figure 1-1. Typical GPIB-120B Expansion System (Physical Configuration)

GPIB-120BGPIB GPIB

Computer

(Controller, Talker,

and Listener)

Printer

(Listener)

Multimeter

(Talker and Listener)

Unit Under Test

Signal Generator

(Listener)

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Chapter 1 Introduction

Figure 1-2. Typical GPIB-120B Expansion System (Logical Configuration)

GPIB

Computer

(Controller, Talker,

and Listener)

Printer

(Listener)

Multimeter

(Talker and Listener)

Unit Under Test

Signal Generator

(Listener)

With the GPIB-120B, you can overcome the following two configuration restrictions imposed by the ANSI/IEEE Standard 488.1-1987:

• An electrical loading limit of 15 devices per contiguous bus.

• A cable length limit of 20 m total per contiguous bus or 2 m multiplied by the number of devices on the bus, whichever is smaller.

With each GPIB-120B, you can add up to 14 additional devices to the bus. The GPIB-120B appears as a device load on each side of the expansion; therefore, one GPIB-120B increases the maximum load limit from 15 devices to 28 devices. The cable length limit for the system is also increased an additional 4 m to 20 m, depending on the number of devices on that side of the expansion.

All signal expansion is bidirectional, meaning that Controllers, Talkers, and Listeners can be on either side of the expander. The GPIB-120B light-emitting diodes (LEDs) indicate the location of the System Controller, Active Controller, and Source Handshaker, with respect to the two sides of the expansion.

Because the GPIB-120B is a functionally transparent expander, the same GPIB communications and control programs that work with an unexpanded system can work unmodified with an expanded system.

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GPIB-120B User Manual

What You Need to Get Started

* GPIB-120B

* 10 –18 VDC 9 W power supply

* Standard GPIB cables to connect both sides of the GPIB-120B to buses on either side

Optional Equipment

Contact National Instruments to order any of the following optional equipment.

• Rack-mount kit (part number 194906-01, shown in Figure 1-3)

Figure 1-3. Rack Mount Kit

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Chapter 1 Introduction

• DIN rail mount kit (part number 779689-01, shown in Figure 1-4)

Figure 1-4. DIN Rail Mount Kit

• Shielded GPIB cables

– Type X2 double-shielded GPIB cables (1 m, 2 m, or 4 m)

Unpacking Your GPIB-120B

Follow these steps when unpacking your GPIB-120B.

1. Verify that the package you received contains the following:

• GPIB-120B Isolator/Expander

• 12 VDC power supply

• Power cord appropriate for your location

2. Inspect the shipping container and contents for damage. If the container is damaged, and the damage appears to have been caused in shipment, file a claim with the carrier. If the equipment is damaged, do not attempt to operate it. Contact National Instruments for instructions. Retain the shipping material for possible inspection by carrier or reshipment of the equipment.

3. Verify that the voltage you will be using is in the input range of your power adapter. The GPIB-120B ships with a power adapter capable of working with an input AC voltage between 100 V and 240 V. This adapter provides 12 VDC to the GPIB-120B. This adapter can be replaced as long as the replacement provides the GPIB-120B with a DC voltage between 10 VDC and 18 VDC and has appropriate safety certification marks for country of use. Refer to Appendix C, Specifications, for more information.

To meet FCC emission limits for this Class A device, you must use a shielded GPIB cable. Operating this

equipment with a nonshielded cable may cause interference to radio and television reception in commercial areas.

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Page 13

Hardware Overview

This chapter describes your GPIB isolator/expander.

GPIB-120B LEDs

The GPIB-120B has seven light-emitting diodes (LEDs). The POWER LED on the left side of the isolator/expander is lit whenever you power on the GPIB-120B.

For each bus, an LED indicates the status of the System Controller, Active Controller, or Source Handshake state, as shown in Figure 2-1. LEDs associated with Bus A are green, while those associated with Bus B are amber.

Figure 2-1. Front View GPIB-120B

PWR SC AC SH SC AC SH

GPIB-120B

Isolator / Expander

Power On (PWR)

When you power on the GPIB-120B, all circuitry is cleared to an initialized state. The isolation/expansion system is fully operational when you power on the GPIB-120B and your instruments are connected. Where there is GPIB activity, keep at least two-thirds of the devices on both buses powered on.

System Controller Detection (SC)

After you power on, Bus A and Bus B System Controller states are false. If a GPIB device on Bus A asserts IFC or REN, the Bus A System Controller state becomes true, and the Bus B System Controller state becomes false.

If a GPIB device on Bus B asserts IFC or REN, the Bus B System Controller state becomes true and the Bus A System Controller state becomes false.

Active Controller Detection (AC)

After you power on, Bus A and Bus B Active Controller states are false. If a GPIB device on Bus A asserts ATN, the Bus A Active Controller state becomes true and the Bus B Active Controller state becomes false.

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Chapter 2 Hardware Overview

If a GPIB device on Bus B asserts ATN, the Bus B Active Controller state becomes true and the Bus A Active Controller state becomes false.

Source Handshake Detection (SH)

A device is considered a source handshaker if it is an active Controller sourcing command bytes or if it is a Talker sourcing data bytes.

After you power on, Bus A and Bus B Source Handshake states are false.

If a GPIB device on Bus A asserts DAV, the Bus A Source Handshake state becomes true and the Bus B Source Handshake state becomes false.

If a GPIB device on Bus B asserts DAV, the Bus B Source Handshake state becomes true and the Bus A Source Handshake state becomes false.

Data Transfer Modes

The GPIB-120B isolator/expander has two data transfer modes—unbuffered mode and buffered mode. The data transfer mode determines how data is transmitted across the expansion. The switch on the back of the GPIB-120B sets the GPIB isolator/expander operation mode. The default switch setting is for unbuffered transfer mode.

Selecting a Data Transfer Mode

To select a data transfer mode, refer to the following descriptions of each mode.

Unbuffered Mode

In unbuffered mode, each data byte is transmitted using the GPIB double-interlocked handshaking protocol. For long data streams, transfers are slower than transfers using buffered mode. However, the GPIB isolator/expander is transparent in unbuffered mode.

Buffered Mode

In buffered mode, the GPIB isolator/expander uses FIFO (first-in-first-out) buffers to buffer data between the remote and local sides of the isolation barrier. For long data streams, the data throughput is much higher than with unbuffered mode.

However, a few applications may not operate properly in buffered mode. For example, a GPIB device on the local side of the isolator/expander is addressed to talk, another device on the remote side is addressed to listen. When the Talker sources data bytes, the GPIB isolator/expander accepts the data bytes and stores them in a FIFO buffer. At the same time, the GPIB isolator/expander reads data from the FIFO buffer and sources data bytes to the Listener. If the FIFO buffer contains data, the number of bytes sourced by the Talker differs from the number of bytes accepted by the Listener. Therefore, there could be situations in which the talker will assume the listener has accepted data which the listener has not yet received because it is

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GPIB-120B User Manual

ON OFF

BUFFERED

still in the FIFO buffer. If this situation is unacceptable for your application, you must use unbuffered mode, in which the 3-wire interlocked behavior of GPIB is maintained.

Buffered mode applies only to data transfers. GPIB command bytes are not stored in the FIFO buffers; they are transmitted using the GPIB double-interlocked handshaking protocol.

Setting the Data Transfer Mode

To use buffered mode, set the switch to the ON position, as shown in Figure 2-2. To use unbuffered mode, set the switch to the OFF position.

Figure 2-2. Switch Setting for Buffered Mode

Note The switch to select buffered or unbuffered mode is recessed to avoid

unintentional toggling during operation of the GPIB-120B. Flipping the switch may require a flathead screwdriver or similar tool.

Verify that the switch on your GPIB isolator/expander is in the desired position before powering on the unit.

Data Direction Control

Bus B sends the data lines to Bus A if the Bus B Source Handshake state is true or if a Controller on Bus A is conducting a parallel poll.

Bus A sends the data lines to Bus B if the Bus A Source Handshake state is true or if a Controller on Bus B is conducting a parallel poll.

Parallel Poll Detection

Controllers can conduct parallel polls on Bus A or Bus B, and devices on both Bus A and Bus B can respond to parallel polls.

If a Controller on Bus A conducts a parallel poll, the parallel poll detection circuitry on side B conducts a parallel poll on Bus B. The parallel poll result is driven on the data lines of Bus A.

If a Controller on Bus B conducts a parallel poll, the parallel poll detection circuitry on side A conducts a parallel poll on Bus A. The parallel poll result is driven on the data lines of Bus B.

Refer to the Parallel Poll Operation section in this chapter for important information about conducting parallel polls with the GPIB-120B.

Page 16

Chapter 2 Hardware Overview

Parallel Poll Operation

According to IEEE 488, devices must respond to a parallel poll within 200 ns after the Controller-In-Charge (CIC) asserts the Identify (IDY) message—Attention (ATN) and End or Identify (EOI). The CIC waits at least 2 µs before reading the Parallel Poll Response (PPR). In some cases, a remote device on an expanded system cannot respond to parallel polls this quickly because of propagation delays across the expander and the longer cables.

When the GPIB-120B notices that a GPIB controller is conducting a parallel poll, it sends a message to the secondary side to initiate a parallel poll. The parallel poll on the secondary side is of the same duration as the poll on the primary side, but delayed by the time it takes to get the message to the secondary side. In the GPIB-120B this time is approximately 400 ns. When the poll on the primary side finishes, a message is sent to finish it on the secondary side, where the poll finishes about 400 ns later. Therefore, if the secondary side of the GPIB-120B waited until the end of its parallel poll to send the result of the poll to the primary side, it would be after the primary side poll has ended. Thus the controller would miss the responses of the devices on the secondary side.

To solve this problem, the secondary side of the GPIB-120B samples the state of the bus every 600 ns during parallel polls and sends that data back to the primary side. Therefore, taking the start of the poll on the primary side as time 0, the state of the secondary bus is sent to the primary side at times 600 ns, 1200 ns, 1800 ns and so on, and again when the poll actually ends.

For slow devices or topologies in which a device on the secondary bus responds to the parallel poll after the last data packet was sent to the primary side, the controller would miss the response from this device. If you encounter this situation, you must configure your controller to conduct parallel polls longer than 2 µs.

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Page 17

Configuring and Using Your Hardware

This chapter describes how to configure and use your GPIB-120B.

Connecting the GPIB-120B

To connect the GPIB-120B, follow the steps below.

1. Make sure that the power switch on the isolator/expander is in the off (0) position.

2. Plug the utility power cord of your 12 VDC power supply into an acceptable electrical outlet (100-240 VAC). Plug the other end of the power cord into the power supply. Connect the 12 VDC output of the power supply into the GPIB-120B rear panel.

3. Link your GPIB instrument(s), board(s), and other device(s) to the GPIB-120B with appropriate cables.

4. Verify that the switch is in the data transfer mode required for your application. Refer to the

Setting the Data Transfer Mode section in Chapter 2, Hardware Overview.

5. Move the power switch to the on (1) position.

Page 18

GPIB Basics

This appendix describes the basic concepts of GPIB, including its physical and electrical characteristics, and configuration requirements.

The ANSI/IEEE Standard 488.1-1987, also known as General Purpose Interface Bus (GPIB), describes a standard interface for communication between instruments and controllers from various vendors. It contains information about electrical, mechanical, and functional specifications. GPIB is a digital, 8-bit parallel communications interface with data transfer rates of 1 Mbyte/s and higher, using a three-wire handshake. The bus supports one System Controller, usually a computer, and up to 14 additional instruments. The ANSI/IEEE Standard 488.2-1992 extends IEEE 488.1 by defining a bus communication protocol, a common set of data codes and formats, and a generic set of common device commands.

Types of Messages

Interconnected GPIB devices communicate by passing messages through the interface system, including device-dependent messages and interface messages.

• Device-dependent messages, also called data or data messages, contain device-specific information, such as programming instructions, measurement results, machine status, and data files.

• Interface messages, also called commands or command messages, manage the bus itself. Interface messages initialize the bus, address and unaddress devices, and set device modes for remote or local programming.

The term command as used here does not refer to device instructions, which are also called commands. Those device-specific instructions are data messages.

Talkers, Listeners, and Controllers

GPIB devices can be Talkers, Listeners, or Controllers. A Talker sends out data messages. Listeners receive data messages. The Controller, usually a computer, manages the flow of information on the bus. It defines the communication links and sends GPIB commands to devices.

Some devices can play more than one role. A digital voltmeter, for example, can be a Talker and a Listener. If your system has a National Instruments GPIB interface and software installed, it can function as a Talker, Listener, and Controller.

Page 19

Appendix A GPIB Basics

The GPIB is like a typical computer bus, except that the typical computer has circuit cards interconnected via a backplane bus, whereas the GPIB has standalone devices interconnected via a cable bus.

The role of the GPIB Controller is similar to the role of the CPU of a computer, but a better analogy is to the switching center of a city telephone system. The switching center (Controller) monitors the communications network (GPIB). When the center (Controller) notices that a party (device) wants to make a call (send a data message), it connects the caller (Talker) to the receiver (Listener).

The Controller addresses a Talker and a Listener before the Talker can send its message to the Listener. After the message is transmitted, the Controller may unaddress both devices.

Some bus configurations do not require a Controller. For example, one device may always be a Talker (called a Talk-only device) and there may be one or more Listen-only devices.

A Controller is necessary when the active or addressed Talker or Listener must be changed. The Controller function is usually handled by a computer.

With the GPIB interface board and its software your personal computer plays all three roles.

• Controller—to manage the GPIB

• Talker—to send data

• Listener—to receive data

Controller-In-Charge and System Controller

You can have multiple Controllers on the GPIB, but only one Controller at a time can be the active Controller, or Controller-In-Charge (CIC). The CIC can be either active or inactive (standby). Control can pass from the current CIC to an idle Controller, but only the System Controller, usually a GPIB interface, can make itself the CIC.

GPIB Signals and Lines

Devices on the bus communicate by sending messages. Signals and lines transfer these messages across the GPIB interface, which consists of 16 signal lines and 8 ground return (shield drain) lines. The 16 signal lines are discussed in the following sections.

Data Lines

Eight data lines, DIO1 through DIO8, carry both data and command messages.

Handshake Lines

Three hardware handshake lines asynchronously control the transfer of message bytes between devices. This process is a three-wire interlocked handshake, and it guarantees that devices send

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Page 20

GPIB-120B User Manual

and receive message bytes on the data lines without transmission error. Table A-1 summarizes the GPIB handshake lines.

Table A-1. GPIB Handshake Lines

Line Description

NRFD (not ready for data) Listening device is ready/not ready to receive a message byte.

Also used by the Talker to signal high-speed GPIB transfers.

NDAC (not data accepted) Listening device has/has not accepted a message byte.

DAV (data valid) Talking device indicates signals on data lines are stable (valid)

data.

Interface Management Lines

Five hardware lines manage the flow of information across the bus. Table A-2 summarizes the GPIB interface management lines.

Table A-2. GPIB Interface Management Lines

Table Head Table Head

ATN (attention) Controller drives ATN true when it sends commands and false

when it sends data messages.

IFC (interface clear) System Controller drives the IFC line to initialize the bus and

make itself CIC.

REN (remote enable) System Controller drives the REN line 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 Controller.

EOI (end or identify) Talker uses the EOI line to mark the end of a data message.

Controller uses the EOI line when it conducts a parallel poll.

Physical and Electrical Characteristics

Devices are usually connected with a cable assembly consisting of a shielded 24-conductor cable with both a plug and receptacle connector at each end, as shown in Figure A-1. With this design, you can link devices in a linear configuration, a star configuration, or a combination of the two configurations. Figure A-2 shows the linear and star configurations.

Page 21

Appendix A GPIB Basics

Figure A-1. GPIB Connector and the Signal Assignment

DIO1 DIO2 DIO3 DIO4

EOI

DAV NRFD NDAC

IFC

SRQ

ATN

SHIELD

10 11 12

21 22 23

DIO5 DIO6 DIO7 DIO8 REN GND (TW PAIR W/DAV) GND (TW PAIR W/NRFD) GND (TW PAIR W/NDAC) GND (TW PAIR W/IFC) GND (TW PAIR W/SRQ) GND (TW PAIR W/ATN) SIGNAL GROUND

Figure A-2. Linear and Star System Configuration

Device A

Device B

Device C

a. Linear Configuration

A-4 | ni.com

Device DDevice A

Device CDevice B

b. Star Configuration

Page 22

GPIB-120B User Manual

The standard connector is the Amphenol or Cinch Series 57 Microribbon or Amp Champ type. For special interconnection applications, use an adapter cable using a non-standard cable and/or connector.

The GPIB uses negative logic with standard TTL (transistor-transistor logic) level. For example, when DAV is true, it is a TTL low level ( 0.8 V), and when DAV is false, it is a TTL high level ( 2.0 V).

Configuration Requirements

To achieve the high data transfer rate that the GPIB was designed for, you must limit the number of devices on the bus and the physical distance between devices. The following restrictions are typical:

• A maximum separation of 4 m between any two devices and an average separation of 2 m over the entire bus.

• A maximum total cable length of 20 m.

• A maximum of 15 devices connected to each bus, with at least two-thirds powered on.

For high-speed operation, the following restrictions apply:

• All devices in the system must be powered on.

• Cable lengths must be as short as possible with up to a maximum of 15 m of cable for each system.

• There must be at least one equivalent device load per meter of cable.

To exceed these limitations, you can use a bus expander to increase the number of device loads. You can order GPIB-120B bus expanders from National Instruments.

Page 23

Multiline Interface Messages

This appendix lists the multiline interface messages and describes the mnemonics and messages that correspond to the interface functions.

The multiline interface messages are commands defined by the IEEE 488 standard. The messages are sent and received with ATN asserted. The interface functions include initializing the bus, addressing and unaddressing devices, and setting device modes for local or remote programming. For more information about these messages, refer to the ANSI/IEEE Standard

488.1-1987, IEEE Standard Digital Interface for Programmable Instrumentation.

Table B-1. Multiline Interface Messages

Hex Dec ASCII Message Hex Dec ASCII Message

00 0 NUL — 20 32 SP MLA0

01 1 SOH GTL 21 33 ! MLA1

02 2 STX — 22 34 " MLA2

03 3 ETX — 23 35 # MLA3

04 4 EOT SDC 24 36 $ MLA4

05 5 ENQ PPC 25 37 % MLA5

06 6 ACK — 26 38 & MLA6

07 7 BEL — 27 39 ' MLA7

08 8 BS GET 28 40 ( MLA8

09 9 HT TCT 29 41 ) MLA9

0A 10 LF — 2A 42 * MLA10

0B 11 VT — 2B 43 + MLA11

0C 12 FF — 2C 44 , MLA12

0D 13 CR — 2D 45 - MLA13

0E 14 SO — 2E 46 . MLA14

0F 15 SI — 2F 47 / MLA15

10 16 DLE — 30 48 0 MLA16

11 17 DC1 LLO 31 49 1 MLA17

Page 24

Appendix B Multiline Interface Messages

Table B-1. Multiline Interface Messages

Hex Dec ASCII Message Hex Dec ASCII Message

12 18 DC2 — 32 50 2 MLA18

13 19 DC3 — 33 51 3 MLA19

14 20 DC4 DCL 34 52 4 MLA20

15 21 NAK PPU 35 53 5 MLA21

16 22 SYN — 36 54 6 MLA22

17 23 ETB — 37 55 7 MLA23

18 24 CAN SPE 38 56 8 MLA24

19 25 EM SPD 39 57 9 MLA25

1A 26 SUB — 3A 58 : MLA26

1B 27 ESC — 3B 59 ; MLA27

1C 28 FS — 3C 60 < MLA28

1D 29 GS — 3D 61 = MLA29

1E 30 RS — 3E 62 > MLA30

1F 31 US CFE 3F 63 ? UNL

40 64 @ MTA0 60 96 ` MSA0, PPE

41 65 A MTA1 61 97 a MSA1, PPE, CFG1

42 66 B MTA2 62 98 b MSA2, PPE, CFG2

43 67 C MTA3 63 99 c MSA3, PPE, CFG3

44 68 D MTA4 64 100 d MSA4, PPE, CFG4

45 69 E MTA5 65 101 e MSA5, PPE, CFG5

46 70 F MTA6 66 102 f MSA6, PPE, CFG6

47 71 G MTA7 67 103 g MSA7, PPE, CFG7

48 72 H MTA8 68 104 h MSA8, PPE, CFG8

49 73 I MTA9 69 105 i MSA9, PPE, CFG9

4A 74 J MTA10 6A 106 j MSA10, PPE, CFG10

4B 75 K MTA11 6B 107 k MSA11, PPE, CFG11

4C 76 L MTA12 6C 108 l MSA12, PPE, CFG12

B-2 | ni.com

Page 25

GPIB-120B User Manual

Table B-1. Multiline Interface Messages

Hex Dec ASCII Message Hex Dec ASCII Message

4D 77 M MTA13 6D 109 m MSA13, PPE, CFG13

4E 78 N MTA14 6E 110 n MSA14, PPE, CFG14

4F 79 O MTA15 6F 111 o MSA15, PPE, CFG15

50 80 P MTA16 70 112 p MSA16, PPD

51 81 Q MTA17 71 113 q MSA17, PPD

52 82 R MTA18 72 114 r MSA18, PPD

53 83 S MTA19 73 115 s MSA19, PPD

54 84 T MTA20 74 116 t MSA20, PPD

55 85 U MTA21 75 117 u MSA21, PPD

56 86 V MTA22 76 118 v MSA22, PPD

57 87 W MTA23 77 119 w MSA23, PPD

58 88 X MTA24 78 120 x MSA24, PPD

59 89 Y MTA25 79 121 y MSA25, PPD

5A 90 Z MTA26 7A 122 z MSA26, PPD

5B 91 [ MTA27 7B 123 { MSA27, PPD

5C 92 \ MTA28 7C 124 | MSA28, PPD

5D 93 ] MTA29 7D 125 } MSA29, PPD

5E 94 ^ MTA30 7E 126 ~ MSA30, PPD

5F 95 _ UNT 7F 127 DEL —

Multiline Interface Message Definitions

DCL Device Clear GET Group Execute Trigger GTL Go To Local LLO Local Lockout MLA My Listen Address MSA My Secondary Address MTA My Talk Address PPC Parallel Poll Configure

P P E Parallel Poll Enable P P U Parallel Poll Unconfigure S D C Selected Device Clear SPD Serial Poll Disable S P E Serial Poll Enable TCT Take Control U N L Unlisten U N T Untalk

P P D Parallel Poll Disable

Page 26

Specifications

This appendix lists the GPIB-120B isolator/expander specifications and characteristics.

System Configuration

Loading per expansion Up to 14 additional devices (28 total devices in

the expansion system, not including the GPIB-120B on the bus.)

Multiple expansions Permitted in any combination of star or linear

pattern

Performance Characteristics

Maximum transfer rate

Buffered mode > 1.25 Mbytes/s

Unbuffered mode > 450 kbytes/s

Interlocked IEEE 488 handshake Maintained across the expansion in unbuffered

mode

IEEE 488 capability identification codes

SH1 Complete Source Handshake

AH1 Complete Acceptor Handshake

T5, TE5 Complete Talker

L3, LE3 Complete Listener

SR1 Complete Service Request

RL1 Complete Remote Local

PP1, 2 Complete Parallel Poll

DC1 Complete Device Clear

DT1 Complete Device Trigger

Page 27

Appendix C Specifications

C1–5 Complete Controller

E2 Tri-state GPIB driver

Operational Characteristics

Operating modes Buffered or unbuffered (interlocked) mode

Electrical Characteristics

GPIB-120B

Isolation

(Between ports and between each port and the power supply) 2500 VDC dielectric withstand, 5 s max

Input voltage range 10-18 VDC

Current consumption @12 V 300 mA typical

500 mA maximum

Fuse rating and type F 2.2 A 125 V,

surface mount

12 VDC Power Supply

(Shipped with GPIB-120B)

Input voltage range 100-240 VAC

47-63 Hz

Environment

Maximum altitude 2,000 m (at 25 °C ambient temperature)

Pollution Degree 2

Indoor use only.

Operating Environment

Ambient temperature range 0 to 55 °C

C-2 | ni.com

(Tested in accordance with IEC 60068-2-1 and IEC 60068-2-2.)

Page 28

GPIB-120B User Manual

Note For the GPIB-120B to operate correctly over the entire specified ambient

temperature range, stacking the product is not recommended.

Relative humidity range 10% to 90%, noncondensing

(Tested in accordance with IEC 60068-2-56.)

Storage Environment

Ambient temperature range -20 to 70 °C

(Tested in accordance with IEC 60068-2-1 and IEC 60068-2-2.)

Relative humidity range 5% to 95%, noncondensing

(Tested in accordance with IEC 60068-2-56.)

Shock and Vibration

Operational shock 30 g peak, half-sine, 11 ms pulse

(Tested in accordance with IEC 60068-2-27. Test profile developed in accordance with MIL-PRF-28800F.)

Random vibration

Operating 5 to 500 Hz, 0.3 g

Nonoperating 5 to 500 Hz, 2.4 g

rms

(Tested in accordance with IEC 60068-2-64. Nonoperating test profile exceeds the requirements of MIL-PRF-28800F, Class 3.)

Physical Characteristics

Overall dimensions 6.30  3.68  1.24 in.

(16.01  9.35  3.15 cm)

Case material PC-ABS plastic

Weight 8.64 oz (245 g)

GPIB cable Type X2 shielded

Page 29

Appendix C Specifications

6.000 in.

(152.4 mm)

1.120 in.

(28.45 mm)

0.120 in.

(3.05 mm)

1.875 in.

(47.63 mm)

2.250 in.

(57.15 mm)

0.800 in.

(20.32 mm)

3.682 in.

(93.53 mm)

1.441 in.

(36.61 mm)

4 x 4– 40 Threaded Insert Max Insertion 0.190 in. (4.82 mm)

0.152 in.

(3.86 mm)

0.152 in.

(3.86 mm)

0.637 in.

(16.17 mm)

1.795 in.

(45.59 mm)

GPIB-120B

Isolator / Expander

Figure C-1 shows the GPIB-120B dimensions.

Figure C-1. GPIB-120B Dimensions

Note The GPIB-120B has threaded inserts for mounting options.

C-4 | ni.com

Page 30

GPIB-120B User Manual

Safety

This product is designed to meet the requirements of the following standards of safety for information technology equipment:

• IEC 61010-1, EN 61010-1

• UL 61010-1, CSA C22.2 No. 61010-1

Note For UL and other safety certifications, refer to the product label or the

Product Certifications and Declarations section.

Electromagnetic Compatibility

This product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:

• EN 61326-1 (IEC 61326-1): Class A emissions; Basic immunity

• EN 55011 (CISPR 11): Group 1, Class A emissions

• AS/NZS CISPR 11: Group 1, Class A emissions

• FCC 47 CFR Part 15B: Class A emissions

• ICES-001: Class A emissions

Note For the standards applied to assess the EMC of this product, refer to

the Product Certifications and Declarations section.

Note For EMC compliance, operate this device with shielded cabling.

CE Compliance

This product meets the essential requirements of applicable European Directives as follows:

• 2014/35/EU; Low-Voltage Directive (safety)

• 2014/30/EU; Electromagnetic Compatibility Directive (EMC)

Product Certifications and Declarations

Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for NI products, visit ni.com/certification, search by model number or product line, and click the appropriate link in the Certification column.

Environmental Management

NI is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers.

Page 31

Appendix C Specifications

⬉ᄤֵᙃѻક∵ᶧ᥻ࠊㅵ⧚ࡲ⊩ ˄Ё೑

RoHS

Ё೑ᅶ᠋

National Instruments

ヺড়Ё೑⬉ᄤֵᙃѻકЁ䰤ࠊՓ⫼ᶤѯ᳝ᆇ⠽䋼ᣛҸ

(RoHS)

݇Ѣ

National Instruments

Ё೑

RoHS

ড়㾘ᗻֵᙃˈ䇋ⱏᔩ

ni.com/environment/rohs_china

(For information about China RoHS compliance, go to

ni.com/environment/rohs_china

For additional environmental information, refer to the Minimize Our Environmental Impact web page at ni.com/environment. This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.

Waste Electrical and Electronic Equipment (WEEE)

EU Customers At the end of the product life cycle, all NI products must be

disposed of according to local laws and regulations. For more information about how to recycle NI products in your region, visit ni.com/environment/weee.

C-6 | ni.com

Page 32

NI Services

NI provides global services and support as part of our commitment to your success. Take advantage of product services in addition to training and certification programs that meet your needs during each phase of the application life cycle; from planning and development through deployment and ongoing maintenance.

To get started, register your product at

As a registered NI product user, you are entitled to the following benefits:

• Access to applicable product services.

• Easier product management with an online account.

• Receive critical part notifications, software updates, and service expirations.

ni.com/myproducts.

Services and Resources

• Maintenance and Hardware Services—NI helps you identify your systems’ accuracy and reliability requirements and provides warranty, sparing, and calibration services to help you maintain accuracy and minimize downtime over the life of your system. Vis it

services

– Warranty and Repair—All NI hardware features a one-year standard warranty that

is extendable up to five years. NI offers repair services performed in a timely manner by highly trained factory technicians using only original parts at an NI service center.

– Calibration—Through regular calibration, you can quantify and improve the

measurement performance of an instrument. NI provides state-of-the-art calibration services. If your product supports calibration, you can obtain the calibration certificate for your product at ni.com/calibration.

for more information.

ni.com/

• System Integration—If you have time constraints, limited in-house technical resources, or other project challenges, National Instruments Alliance Partner members can help. To learn more, call your local NI office or visit ni.com/alliance.

Page 33

Appendix D NI Services

• Training and Certification—The NI training and certification program is the most effective way to increase application development proficiency and productivity. Visit

ni.com/training for more information.

– The Skills Guide assists you in identifying the proficiency requirements of your

current application and gives you options for obtaining those skills consistent with your time and budget constraints and personal learning preferences. Visit ni.com/

skills-guide

to see these custom paths.

– NI offers courses in several languages and formats including instructor-led classes at

facilities worldwide, courses on-site at your facility, and online courses to serve your individual needs.

• Technical Support—Support at ni.com/support includes the following resources:

– Self-Help Technical Resources—Visit

ni.com/support for software drivers and

updates, a searchable KnowledgeBase, product manuals, step-by-step troubleshooting wizards, thousands of example programs, tutorials, application notes, instrument drivers, and so on. Registered users also receive access to the NI Discussion Forums

ni.com/forums. NI Applications Engineers make sure every question submitted

at online receives an answer.

– Software Support Service Membership—The Standard Service Program (SSP) is a

renewable one-year subscription included with almost every NI software product, including NI Developer Suite. This program entitles members to direct access to NI Applications Engineers through phone and email for one-to-one technical support, as well as exclusive access to online training modules at

self-paced-training

. NI also offers flexible extended contract options that

ni.com/

guarantee your SSP benefits are available without interruption for as long as you need them. Visit ni.com/ssp for more information.

• Declaration of Conformity (DoC)—A DoC is our claim of compliance with the Council of the European Communities using the manufacturer’s declaration of conformity. This system affords the user protection for electromagnetic compatibility (EMC) and product safety. You can obtain the DoC for your product by visiting

ni.com/certification.

For information about other technical support options in your area, visit ni.com/services, or contact your local office at ni.com/contact.

You also can visit the Worldwide Offices section of office websites, which provide up-to-date contact information, support phone numbers, email addresses, and current events.

D-2 | ni.com

ni.com/niglobal to access the branch

Page 34

Index

active controller detection, 2-2

CE compliance specifications, C-5 configuring

data transfer modes, 2-2

buffered, 2-2 setting, 2-3 switch setting, buffered (figure),

2-3

unbuffered, 2-2

hardware, 3-1

parallel poll response modes, 2-4 linear and star system (figure), A-5 requirements, A-5 system configuration specifications, C-1

connector and signal assignment (figure), A-4 controller-in-charge and system controller,

A-2

controllers, A-1

data direction control, 2-3 data transfer modes, 2-2

buffered, 2-2 setting, 2-3 switch setting, buffered (figure), 2-3 unbuffered, 2-2

description of GPIB-120B, 1-1 DIN rail mount kit (figure), 1-4 documentation

National Instruments GPIB-120B User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual