Anritsu 37211B Prelimary Programming Manual

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MODEL

372XXB

VECTOR NETWORK ANALYZER

PRELIMINARY PROGRAMMING MANUAL

Software Version: 1.05

P/N: 10410-00186

REVISION: A

PRINTED: FEBRUARY 1996

490 JARVIS DRIVE ● MORGAN HILL, CA 95037-2809

WARRANTY

The WILTRON product(s) listed on the title page is (are) warranted against defects in materials and workmanship for one year from the date of shipment. WILTRON’s obligation covers repairing or replacing products which prove to be defective during the warranty period. Buyers shall prepay transportation charges for equipment returned to WILTRON for warranty repairs. Obligation is limited to the original purchaser. WILTRON is not liable for consequential damages.

LIMITATION OF WARRANTY

The foregoing warranty does not apply to WILTRON connectors that have failed due to normal wear. Also, the warranty does not apply to defects resulting from improper or inadequate maintenance by the Buyer, unauthorized modification or misuse, or operation outside of the environmental specifications of the product. No other warranty is expressed or implied, and the remedies provided herein are the Buyer’s sole and exclusive remedies.

TRADEMARK ACKNOWLEDGEMENTS

V Connector and K Connector are registered trademarks of WILTRON Company. ANACAT is a registered trademark of EEsof, Inc. Ink Jet and Think Jet are registered trademarks of Hewlett-Packard Co. MS-DOS is a registered trademark of Microsoft Corporation. Excel is a registered trademark of Microsoft Corporation.

NOTICE

WILTRON Company has prepared this manual for use by WILTRON Company personnel and customers as a guide for the proper installation, operation and maintenance of WILTRON Company equipment and computer programs. The drawings, specifications, and information contained herein are the property of WILTRON Company, and any unauthorized use or disclosure of these drawings, specifications, and information is prohibited; they shall not be reproduced, copied, or used in whole

10410-00186, REV: A

Safety Symbols

To prevent the risk of personal injury or loss related to equipment malfunction, WILTRON Company uses the following symbols to indicate safety-related information. For your own safety, please read the information carefully BEFORE operating the equipment.

Symbols used in manuals

DANGER This indicates a very dangerous procedure that could result in serious

injury or death if not performed properly.

WARNING This indicates a hazardous procedure that could result in serious in-

jury or death if not performed properly.

CAUTION This indicates a hazardous procedure or danger that could result in

light-to-severe injury, or loss related to equipment malfunction, if proper precautions are not taken.

Safety Symbols Used on Equipment and in Manuals

(Some or all of the following five symbols may or may not be used on all WILTRON equipment. In addition, there may be other labels attached to products that are not shown in the diagrams in this manual.)

The following safety symbols are used inside or on the equipment near operation locations to provide information about safety items and operation precautions. Ensure that you clearly understand the meanings of the symbols and take the necessary precautions BEFORE operating the equipment.

This indicates a prohibited operation. The prohibited operation is indicated symbolically in or near the barred circle.

This indicates a compulsory safety precaution. The required operation is indicated symbolocally in or near the circle.

This indicates warning or caution. The contents are indicated symbolically in or near the triangle.

This indicates a note. The contents are described in the box.

These indicate that the marked part should be recycled.

372XXB PM SAFETY-1

For Safety

WARNING

Always refer to the operation manual when working near locations at which the alert mark, shown on the left, is attached. If the operation, etc., is performed without heeding the advice in the operation manual, there is a risk of personal injury. In addition, the equipment performance may be reduced.

Moreover, this alert mark is sometimes used with other marks and descriptions indicating other dangers.

WARNING

When supplying power to this equipment, connect the accessory 3-pin power cord to a 3-pin grounded power outlet. If a grounded 3-pin outlet is not available, use a conversion adapter and ground the green wire, or connect the frame ground on the rear panel of the equipment to ground. If power is supplied without grounding the equipment, there is a risk of receiving a severe or fatal electric shock.

Repair

WARNING

This equipment can not be repaired by the operator. DO NOT attempt to remove the equipment covers or to disassemble internal components. Only qualified service technicians with a knowledge of electrical fire and shock hazards should service this equipment. There are high-voltage parts in this equipment presenting a risk of severe injury or fatal electric shock to untrained personnel. In addition, there is a risk of damage to precision components.

WARNING

Use two or more people to lift and move this equipment, or use an equipment cart. There is a risk of back injury, if this equipment is lifted by one person.

SAFETY-2 372XXB PM

Table Of Contents

Part 1 — GPIB Interface

Chapter 1 — Model 372XXB GPIB Programmer Interface

This chapter provides an introduction to the 372XXB GPIB programmer interface and GPIB communications.

Chapter 2 — GPIB Programming Basics

This chapter provides programming information, including equipment and controller setup and elemental GPIB programming techniques.

Chapter 3 — Model 372XXB Programming Examples

This chapter provides sample program elements that demonstrate common 372XXB operations. These sample elements are useful as an aid in developing 372XXB programs.

Part 2 — GPIB Function Groups

Chapter 4 — Measurement Functions

This chapter provides a detailed description of the 372XXB specific GPIB commands that control the various data display and measurement control functions of the 372XXB.

Chapter 5 — Calibration Functions

This chapter describes the 372XXB error correction (calibration) functions and the commands used to implement a measurement calibration.

Chapter 6 — Markers and Limits Functions

This chapter describes commands used for data analysis, which consists of markers and limits function commands.

Chapter 7 — Remote-Only Functions

This chapter describes 372XXB functions that support operations typically required when in the remote-only (GPIB) mode. The commands described consist of data transfer, error reporting, SRQ/status reporting, 488.2 common commands, and synchronization..

Chapter 8 — System Functions

This chapter describes the commands used to implement certain system functions. They consist of hard copy, system state, save/recall, disk function, and diagnostics commands.

Chapter 9 — Special Applications Functions

This chapter describes the commands used to implement special measurement functions. They consist of time domain, multiple source, sweep control, rear panel output, and CW sweep commands.

Part 3 — Programming Reference

Chapter 10 — Command Dictionary

This chapter provides an alphabetically-ordered, dictionary-type listing and description of all 372XXB GPIB programming commands. The listing for each command includes relevant details about the command.

372XXB GPIB PM i

Table of Contents (Continued)

Chapter 11 — Instrument Data

This chapter provides general (non-command specific) tabular information for the 372XXB. Much of this information is presented in Chapters 4 through 10, but is provided in this chapter for easy access.

Chapter 12 — Error Messages

This chapter provides a list of all Error Messages including those related to remote-only (GPIB) operation of the 372XXB.

Part 4 — Supplemental Data -

NOT AVAILABLE FOR PRELIMINARY MANUAL

Appendix A — Introduction to the IEEE 488 Bus

This appendix contains an introduction to the IEEE 488 Bus (GPIB). This material is intended to assist new users in understanding GPIB basics.

Appendix B — Front Panel Keys & Menus

This appendix provides description and diagrams for the 372XXB front panel key-groups and menus.

Appendix C — GPIB Quick Reference Guide

This appendix provides a quick reference to all 372XXB GPIB commands. Each reference lists the command name, a brief description of the command function, and a reference to the pertinent Chapter in this manual.

Appendix D — 360B Compatibility Information

This appendix provides compatibility information for GPIB operation and programming between the 372XXB Series and the 360B Series of WILTRON Vector Network Analyzers. It includes a listing of all 372XXB commands that shows the degree of functional compatibility between the 372XXB commands and the associated 360B commands.

ii 372XXB GPIB PM

Part 1 The GPIB Interface

This part consists of three chapters that describe how the IEEE- 488 (GPIB) interface is implemented within the 372XXB Vector Network Analyzer and how to perform basic GPIB communications operations.

Chapter 1 – briefly describes the 372XXB GPIB programmer in-

terface and describes the communication to and from the interface during remote-only (GPIB) operation of the 372XXB.

Chapter 2 – provides a tutorial for performing basic GPIB opera-

tions such as sending and receiving messages, synchronizing instrument operations, setting timeouts, and status checking.

Chapter 3 – provides sample program elements to familiarize

the user with 372XXB programming techniques. They are also useful as an aid in developing 372XXB programs.

Chapter 1 Model 372XXA GPIB Programmer Interface

Table of Contents

1-1 INTRODUCTION . . . . . . . . . . . . . . . . . . 1-3

1-2 REMOTE OPERATION INTERFACE . . . . . . . 1-3

GPIB Setup Menu . . . . . . . . . . . . . . . . 1-3

Interface Connection . . . . . . . . . . . . . . 1-4

Local Operation Key . . . . . . . . . . . . . . 1-4

Remote Operation LED Indicators . . . . . . . 1-6

1-3 GPIB COMMUNICATION . . . . . . . . . . . . . . 1-7

Bus Interface Function Messages . . . . . . . 1-7

372XXB Specific Messages . . . . . . . . . . . 1-7

Separator Characters . . . . . . . . . . . . . . 1-8

Terminator Character . . . . . . . . . . . . . . 1-8

GPIB Error Conditions . . . . . . . . . . . . . 1-8

Testing the 372XXB GPIB Operation . . . . . 1-9

1-4 IEEE 488.2 DOCUMENTATION SUMMARY . . . 1-10

Chapter 1 Model 372XXB GPIB Programmer Interface

1-1

1-2

INTRODUCTI ON

REMOTE OPERATION INTERFACE

GPIB Setup Menu The 372XXB VNA GPIB address defaults to 6. This value may be

System State

Default

Pr ogram

Utility

This chapter contains a brief introduction to the 372XXB GPIB interface and programming environment.

The following paragraphs describe the 372XXB facilities for remote operation.

The 372XXB fully supports the IEEE 488.2–1992 GPIB standard. All 372XXB front panel functions (except Power on/off and GPIB Test) can be controlled remotely using the GPIB commands listed in this manual and an external computer equipped with an IEEE 488 GPIB controller. When in the GPIB operating mode, the 372XXB VNA functions as both a listener and a talker.

changed via the Utility Menu key’s GPIB ADDRESSES menu (below).

SELECT UTILITY

FUNCTION OPTIONS

GPIB ADDRESSES DISPLAY

INSTRUMENT STATE PARAMS

GENERAL DISK UTILITIES

CALIBRATION COMPONENT UTILITIES

COLOR CONFIGURATION

DATA ON(OFF) DRAWING

BLANKING FREQUENCY INFORMATION

PRESS <ENTER>

TO SELECT

OR TURN ON/OFF

GPIB ADDRESSES

IEEE 488.2 GPIB INTERFACE

ADDRESS 6

DEDICATED GPIB INTERFACE

EXTERNAL SOURCE 4

PLOTTER 8

POWER METER 13

FREQUENCY COUNTER 7

Figure 1-1. GPIB Address Menu

372XXB GPIB PM 1-3

USER THE GPIB PROGRAMMER INTERFACE INTERFACE

Interface Connection Connect your external controller to the IEEE 488.2 GPIB interface con-

nector on the rear panel (left). A pinout listing of this connector is contained in Table 1-1.

Dspay

Pr nt er O ut

VG A O UT

C RT De gau ss CR T Brt

10 M Hz Re f

Ex te rn a I/O

Bas Fuses

Po r t 1 Po r t 2

IEEE 488.2 Interface

Dedicated GPIB Interface

Display

Reference Extenson

RAO ut

RA I n RB I n RB O ut

NOTE

Do not connect your external GPIB controller to the “Dedicated GPIB Interface” connector (located below the “IEEE

488.2 GPIB interface” connector (left). This dedicated GPIB port is used by the 372XXB to control external GPIB devices, such as a plotter, second frequency source, frequency counter, or a power meter.

The GPIB system can accommodate up to 15 devices at any one time. To achieve maximum performance on the bus, proper timing and voltage level relationships must be maintained. If either the cable length between separate instruments or the accumulated cable length between all instruments is too long, the data and control lines cannot be driven properly and the system may fail to perform. The following guidelines should be observed:

No more than 15 instruments may be installed on the bus (including the controller).

Total accumulative cable length (in meters) may not exceed two times the number of bus instruments or 20 meters—whichever is less.

Individual cable length should not exceed 4 meters. 2/3 of the devices must be powered on. Devices should not be powered on while bus is in operation (that

is; actively sending or receiving messages, data, etc.). Minimize cable lengths to achieve maximum data transfer rates.

Local Operation Key Press the Ret Loc key (below) to quickly restore the 372XXB to local op-

eration. Local operation will be restored unless the 372XXB is programmed for local lockout; the Local Lockout LED indicator will be lit.

Enter

10-3Clear

Channel

Setup

Limits

Ch 1 Ch 2

Marker

Readout

Ch 3 Ch 4

Marker

Graph

Set

Type

Default

Utility

Program

Save/

Begin

Apply

Recall

Cal

Scale

Start

Stop

Ref

Params

Plane

Data

Points

Device

Domain

Hold

Auto

Option

Video

Scale

IF BW

Avg/

Trace

Smooth

Average

Trac e

Memory

Smooth

Clear

Ret Loc

1-4 372XXB GPIB PM

12 11 10

9 8 7 6 5 4 3 2 1

24 23 22 21 20 19 18 17 16 15 14 13

THE GPIB PROGRAMMER USER INTERFACE INTERFACE

Pinout Diagram

PIN NAME DESCRIPTION

1-4 DIO 1 thru DIO 4

Data Input/Ou tpu t.

Bits are HIGH with the data is lo gi cal 0 an d LOW when the data

is logical 1.

5EOI

End Or Identify.

A low-true state indicates that the last byte of a multibyte me ssage

has been placed on the line.

6DAV

Data Valid.

A low-true state indicates that the tal ker has (1) sensed that NRFD is LOW, (2) placed a byte of data on the bus, and (3) wa ited an approp riate le ngth of time for the data to settle.

7 NRFD

Not Ready For Da ta.

A high-true state indicates that valid d ata has not yet bee n

accepte d b y a li ste ner.

8 NDAC

Not Data Accepted.

A low-true state indicate s that the cu rrent data byte has been

accepted for inte rnal pro cessing by a listen er.

9IFC

Interface Clear.

A low-true state places all bus instrum ents in a known state—such

as, unaddressed to talk, unaddressed to listen, and service requ est idle.

10 SRQ

Service Request.

A low-true state indicates that a bus instrument needs service from

the contro lle r.

11 ATN

Attention.

A low-true state enables the controller to respond to both it’s own listen/talk address an d to ap propria te interfa ce me ssage s — such as, d evice clear and serial poll.

12 Shield Ground Poin t.

13-16 DIO 5 thru DIO 8

Data Input/Outp ut.

Bits are high with the data is lo gical 0 a nd L OW when the da ta

is logical 1.

17 REN

Remote En ab le.

A low-true state enables bus instru ments to be opera ted remotel y,

when addressed.

18-

GND Logi c gro un d.

Figure 1-2. Pinout Diagram, IEEE 488.2 GPIB Connector

372XXB GPIB PM 1-5

USER THE GPIB PROGRAMMER INTERFACE INTERFACE

Enter

123

10-3Clear

0.-

Channel

Setup

Data

Poi nts

Devi ce

Domain

Hold

Auto

Option

Vid eo

Scale

IF BW

Avg/

Trace

Smooth

Average

Trace

Memory

Smooth

Default

Utility

Begin

Apply

Program

Cal

GPIB Remote

Talk Listen

SRQ Local Lockout

Limits

Ch 1 Ch 2

Marker

Readout

Ch 3 Ch 4

Marker

Graph

Set

Type

Save/ Recall

Scale

Start

Stop

Ref

Params

Plane

Remote Operation

LED Indicators

GPIB Remote Indicators (above) signal operational status of the GPIB, as described below:

Remote:

Lights when the 372XXB switches to remote (GPIB) control. It remains lit until the unit returns to local control.

Tal k:

Lights when you address the 372XXB to talk and remains lit until unaddressed to talk.

Listen:

Lights when you address the 372XXB to listen and remains lit until unaddressed to talk.

SRQ:

Lights when the 372XXB sends a Service Request (SRQ) to the external controller. The LED remains lit until the 372XXB receives a serial poll or until the controller resets the SRQ function.

Local Lockout:

Lights when a local lockout message is received. The LED remains lit until the message is rescinded. When lit, you cannot return the 372XXB to local control via the front panel.

Audible Indicators A single beep is issued as follows:

(1) on a GPIB error, (2) when a user warning is issued (see Chapter 12, Operational Error

Messages)

(3) when a test limit line has been exceeded, if the limits testing beep

function has been set (see Chapter 6) (4) on system reset. (5) any time the user’s attention is required, such as at the end of a

calibration step.

1-6 372XXB GPIB PM

THE GPIB PROGRAMMER GPIB INTERFACE COMMUNICATIONS

1-3

GPIB COMMUNICATION

The following paragraphs present a short summary of 372XXB GPIB communication. Subjects covered are program messages, separator/termination characters, status reporting, and GPIB error conditions and corresponding 372XXB responses. Refer to Chapter 7, Remote-Only Operation, for detailed description of these topics.

The primary GPIB messages that effect 372XXB operation consist of two major groups; Bus Interface Function messages, and Instrument Specific messages.

Bus Interface

Function Messages

These are low level bus messages defined by IEEE 488.1. A discussion of these messages is beyond the scope of this programming manual. For further information, please refer to your GPIB controller documentation and/or to IEEE 488.1 Standards documents. Also refer to Appendix A at the end of this Programming Manual for a brief primer on the GPIB Interface. Table 1-1 summarizes some of the key Interface Function Messages and the 372XXB response to them.

Table 1-1. IEEE-488 Interface Function Messages

Interfa ce F u n cti o n

Message

DCL SDC

Message Function

Device Clear Selected Device Clear

Addressed

Command

Yes

372XXB VNA Response

Resets the 372XXB GPI B com munica tion funct ions. Resets the 372XXB GPI B com munica tion funct ions.

GTL Go To Local Yes Returns the 372XXB to local (front panel) contro l. GET Group Execute

Trigger

IFC Interface Clear No Stops the 372XXB GPIB from talking/list enin g. LLO Local Lockout No Disables the front panel RETURN TO LOCA L key. REN Remot e Enable No Places the 372XXB in remote when addressed to listen.

372XXB Specific

Messages

The 372XXB specific GPIB messages (also known as commands, queries, and mnemonics) are used to control 372XXB front panel func-

Yes Executes a string of comm ands defin ed by the IEEE 488. 2

common comm and *D DT. A GET is also done b y using the *TRG command (see Chapter 10, Command Dictionary).

tions. They also provide for remote only operations such as data transfers, status reporting and service request generation, error reporting, and instrument-to-application program timing synchronization.

Refer to Chapter 10, Command Dictionary; Appendix C, Quick Reference Guide; and Chapters 4-9 for information on all 372XXB commands. The commands are organized both alphabetically and by command function groups. There are many examples throughout the this manual to assist you in learning and using a desired command.

372XXB GPIB PM 1-7

GPIB THE GPIB PROGRAMMER COMMUNICATIONS INTERFACE

Most 372XXB commands are three character contractions of their functional descriptions. Examples include: OM1 (input Frequency List), TRS (Trigger Sweep), WFS (Wait for a Full Sweep), OFD (Output Final [display format] Data), and PFS (Print Full Screen).

Numeric parameter entry commands must be followed by a nu- meric value. These commands can optionally accept a units or suffix terminator mnemonic. For example, 2 GHz.)

Query commands, typically ending in a question mark (?), are used to inquire about the state of a particular instrument function. Many 372XXB setup commands have corresponding query commands listed in the same section as the basic setup command. An example is the

MK1? query. It outputs the setting of Marker 1 Frequency, where the MK1 command sets Marker 1 frequency.

IEEE 488.2 Common commands, which always start with the

asterisk character (*), are defined by the IEEE 488.2 Standard. They are used to implement many standard instrument GPIB operations such as querying when an operation completes, status reporting, self test, and querying the instrument identification string. These commands are described throughout the Programming Manual in the specific funtional group where they are used. A consolidated listing of these commands can be found in Table 1-2, item 12 below and in Chapter 7. An example IEEE 488.2 Common command is the *IDN? query (Output Instrument ID String.)

SRT 2 GHZ (set start frequency to

(Output Marker 1), IFV

Separator

Characters

Terminator

Character

GPIB Error

Conditions

Separator characters are used to delimit program message elements sent to or received from the 372XXB. The permitted characters: semicolon (;), comma (,), and space ( ) and their usage is shown below.

Character Used to separate

;

Space A command , its num eric al entry valu e, and suf f ix mnemo nic.

The only allowed terminator character for 372XXB GPIB messages is the the linefeed character (0A, decimal 10).

The 372XXB responds to GPIB errors in the following manner:

A beep is issued. An error message is displayed on the screen.

Multiple commands and multiple out put respon se messa ges. Multiple ASCII data e leme nts for a single comm and.

1-8 372XXB GPIB PM

THE GPIB PROGRAMMER GPIB INTERFACE COMMUNICATIONS

A bit is set in the Standard Event Status Register, and, if enabled, an SRQ is generated.

An entry is written into the non-volatile Service Log describing the error condition, along with time and date and, often, details helpful in handling the error. When full, error entries at the bottom of the log are removed to make room for new entries.

If the error is GPIB related, the error message and the offending program message, if applicable, can be output over the GPIB via a query command. The previous error, if any, is also available via another query.

The bits set in the Standard Event Status Register for GPIB errors are as follows:

Bit 5 - Command Error (CME)

Invalid syntax, unrecognized command or command arguments, separaters or terminators that do not conform to correct IEEEE 488.2 formats. The 372XXB will ignore the remainder of commands in that

program message.

Testing the 372XXB

GPIB Operation

Bit 4 - Execution Error (EXE)

This bit is set if: (1) A data entry parameter is out of range or not applicable. (2) Action is impossible. (3) Action is not possible in the current context or instrument state, or

if a required option is not fitted.

Bit 3 - Device Dependant Error (DDE)

This bit is set if a valid requested action failed due to an instrument specific error condition, such as attempting to access a bad floppy disk.

Bit 2 - Query Error (QYE)

This bit is set if the 372XXB cannot provide the requested data. For example, if an output is attempted when no data has been requested or available, or if the output buffer is cleared due to sending more commands when data from a previous request has not yet been output.

Refer to Chapter 12, Error messages, for a listing of all 372XXB error messages (including GPIB errors).

The following test can be used to check your GPIB cable and 372XXB GPIB connectors.

1. Disconnect all GPIB cables from the 372XXB.

2. Connect your GPIB cable between the two GPIB connectors on the 372XXB rear panel.

3. Invoke the test from the front panel as follows: Option Menu key, DIAGNOSTICS, PERIPHERAL TESTS, GPIB TEST. The test will run for a few seconds, then report the result on the front panel display.

372XXB GPIB PM 1-9

IEEE 488.2 THE GPIB PROGRAMMER DOCUMENTATION SUMMARY INTERFACE

1-4

Table 1-2. 372XXB IEEE 488.2 Standard Documentation Summary (1 of 3)

Number Requirement Item Impl ementation in VNA

IEEE 488.2 DOCUMENTATION SUMMARY

1 Interface Functio n Subse ts Implemented SH1, AH1, T6, L4, SR1, RL1, PP1, DC1, DT1, C0, E2. 2 Device behavior w he n th e user (un it) GPI B addres s

is set outside of the 0–30 range

3 When is a user address change recog nized? New address is accepted and entry color remains

4 Description of settings at power-on The front panel setup that was in effect prior to power

Table 1-2 provides answers to the “Device Documentation Requirements” listed in the IEEE Standard 488.2-1992. It is also a good summary of the GPIB operational characteristics of the 372XXB.

VNA returns an Out-of-Range error , issues an audible beep, and the entry color on front panel menu display is changed to red. Ente red addr ess is not accept ed.

green.

down will be restored, taken out of hold if it was previously set. Periodic I F Cal will be returned to timed operation.

Memories saved:

1. GPIB ad dress

2. Internal hardware calibration dat a

3. Information repor te d via the *IDN? and *OPT? queries.

4. Calibration coefficient s

5. Normalized trace data

6. Stored front pane l se tu ps

Memories Cleared:

1. Service Request message.

2. Standard event statu s register (excep t the Power-On bit is set)

3. Extended event status register

4. Limit pass/fail st at us re gister

5. Enable registers for items 2 thru 4, above.

6. GPIB input and output que ues.

7. Trigger action for *TRG and GET r eset t o n u ll.

Data Tr ansf er :

1. Data tr a ns fer is reset to MSB fir st for numerical array data transfer s.

2. Data transfer format is reset t o default, ASCII mode (FMA) for numerical array transf er s.

3. Data pair forma t for OFD/I FD/ O M 1- OM6 comma nds is set to default (off) mo de. (See com ma nd DPR0.)

Menu Displa y ed:

Setup Menu

except:

the 372XXB will be

1-10 372XXB GPIB PM

THE GPIB PROGRAMMER IEEE 488.2 INTERFACE DOCUMENTATION SUMMARY

Table 1-2. 372XXB IEEE 488.2 Standard Documentation Summary (2 of 3)

Number Requirement Item Impl ementation in VNA

5 Message exchan ge opt ions

a. Size and behavior of input buf fe r a. Default size = 3 KByte. Size increa ses to re quire d

amount , as need ed, for <Arbitr ar y B lock> t ransf er s. For the <Indefinit e Len gth Ar bitr ary Block> da ta element s, the inp ut buf f er size f or that element i s 64 Kbyte. At t empt in g to pr ogr am more dat a tha n 64 KByte will cause a loss of all data for that element. A DDE error message will be issued to indicate this con dition. F or <Def inite Len gth Ar bitr ary Block> data elements, an attempt is made to set the buffer size for that elem ent t o the size indicated in the header . If there is in suf ficien t system memory available at the time, a ll data for that eleme nt is lost. A DDE error messa ge will be issued to indicat e this condition.

b. Queries that return m ore than one <RESPON S E

MESSAGE UNIT> c. Queries that generate a respo nse w he n par sed c. Al l d. Queries that generat e a response w he n rea d d. None e. Commands that are coupled e. None

6 Functional element s us ed in cons truction of device-

specific commands.

b. None

See command desc ript ions.

7 Buffer size limitations 372XXB Attempts to allocate amou nt re quired; sets

DDE error if not possible. (See 5a., above)

8 <PROGRAM DAT A> elem ents that may appear

within an <expression>

9 Response synt ax for querie s See command desc ript ions.

10 Description of dev ice-to- dev ice messag e trans fer

traffic that does not follow the rules for <RESPON SE MESSAGES>

11 Size of block data responses V ar iable, See comm and descript ions for de tails. 12 IEEE.488.2 Comm on co mman ds and querie s that

are imp le me nted

13 State of VNA following the successful complet ion of

the Calibration quer y

14 Maximum lengt h of the block us ed to def ine t he

trigger macro (1 .) The met hod o f inter pret in g *TRG within a *DDT command sequence ( 2.)

N/A (expre ssions are not used)

None

*CLS, *DDT, *DDT?, *ESE, *ESE?, *ESR? , *IDN?, *IST?, *OPC, *OPC?, *OPT?, *PRE, *PRE?, *RST, *SRE, *SRE?, *STB?, *TRG, *TST?, *WAI

Normal State

1. 255 chara ct ers.

2. On execution, the 372XXB returns a command error and ignores the rest of the string.

372XXB GPIB PM 1-11

IEEE 488.2 THE GPIB PROGRAMMER DOCUMENTATION SUMMARY INTERFACE

Table 1-2. 372XXB IEEE 488.2 Standard Documentation Summary (3 of 3)

Number Requirement Item Impl ementation in VNA

15 Maximum length and complexity of macro labels;

maximum lengt h of block used t o define a m acr o; and how recursion is handle d durin g macro

expansion, if macro comma nds ar e imple me nted. 16 Response to common quer y *IDN?. WILTRON, <Model>, <SN>, <SW rev ision > 17 Size of the protected us er data storag e are a, if the

*PUD command or *PUD? query are implemented. 18 Size of resource de scrip tion , if the *RDT com mand

or *RDT? query are implemented. 19 States affect ed by *RST, *LRN?, *RCL, and *SAV. *RST = default state (see Ch apt er 11),

20 Scope of the self test performe d by *TST? comm and . Fully automated internal har dwar e testing/ re por ting .

21 Additional status data structu res used in stat us

reporting. 22 Statement des cribing wh ether each co mman d is

overlapped or sequ ent ial. 23 Functional criteria that is met when an operatio n

complete message is generat ed in respons e to that

command.

N/A

*LRN, *RCL, *SAV not implemented

Failure results, if any, are written to the internal nonvolatile service log for user access .

Limits Event Status and Extended Event Status registers; refer to Chapter 7 for details.

All commands are sequential.

N/A – No overlappe d comm ands .

24 Descriptions used for infinit y and not-a- num ber. N/A

1-12 372XXB GPIB PM

Chapter 2 GPIB Programming Basics

Table of Contents

2-1 INTRODUCTION . . . . . . . . . . . . . . . . . . 2-3

2-2 EQUIPMENT AND CONFIGURATION . . . . . . 2-3

Required Equipment . . . . . . . . . . . . . . 2-3

Configuration . . . . . . . . . . . . . . . . . . 2-4

2-3 GPIB PROGRAM ELEMENTS . . . . . . . . . . . 2-5

National Instruments GPIB Interface . . . . . 2-5

Definitions . . . . . . . . . . . . . . . . . . . . 2-5

2-4 INITIALIZING THE GPIB . . . . . . . . . . . . . 2-6

2-5 SHUTTING DOWN THE GPIB SYSTEM . . . . . 2-6

2-6 DETECTING GPIB ERRORS . . . . . . . . . . . . 2-7

Full Error Detection . . . . . . . . . . . . . . . 2-7

Limited Handling Error Detection . . . . . . . 2-7

NI488 Global Variables . . . . . . . . . . . . . 2-7

Example . . . . . . . . . . . . . . . . . . . . . 2-7

2-7 SETTING GPIB OPERATION TIME OUT . . . . . 2-8

Example . . . . . . . . . . . . . . . . . . . . . 2-8

2-8 SENDING COMMANDS . . . . . . . . . . . . . . 2-9

Example: . . . . . . . . . . . . . . . . . . . . . 2-9

372XXB Commands Used . . . . . . . . . . . . 2-9

2-9 RECEIVING DATA FROM AN INSTRUMENT . . 2-10

Example: . . . . . . . . . . . . . . . . . . . . . 2-10

Error Handling: . . . . . . . . . . . . . . . . . 2-10

372XXB Commands Used . . . . . . . . . . . . 2-11

2-10 SRQ HANDLING . . . . . . . . . . . . . . . . . . 2-11

Calculating the Binary Weighted

Bit Value . . . . . . . . . . . . . . . . . . . . 2-11

Enabling Service Request . . . . . . . . . . . . 2-11

Example . . . . . . . . . . . . . . . . . . . . . 2-11

Commands Used . . . . . . . . . . . . . . . . . 2-12

NI488 SRQ Functions . . . . . . . . . . . . . . 2-12

2-11 WAITING FOR INSTRUMENT OPERATIONS

TO COMPLETE . . . . . . . . . . . . . . . . . . . 2-13

Example 1 . . . . . . . . . . . . . . . . . . . . 2-13

Example 2 . . . . . . . . . . . . . . . . . . . . 2-13

372XXB Commands Used . . . . . . . . . . . . 2-14

Chapter 2 GPIB Programming Basics

2-1

2-2

INTRODUCTI ON

EQUIPM ENT A ND CONFIGU RATION

Required Equipment The following equipment represents a minimum GPIB controllable

This chapter contains a brief introduction to GPIB programming techniques and describes procedures to be used when preparing GPIB programs for the 372XXB VNA. It includes information about equipment requirements and configuration for GPIB control of the 372XXB VNA, and many programming tips.

Familiarity with manual (front panel) operation of the 372XXB is assumed. (Throughout this section, the 372XXB VNA is referred to simply as “372XXB”.) A complete description of front panel operation is contained in the 372XXB Vector Network Analyzer System Operation Manual.

The programming examples contained in this chapter assume the equipment listed below is present and configured as described.

372XXB VNA system:

A 372XXB Vector Network Analyzer. A computer/controller that supports the IEEE 488 GPIB stand-

ard. The examples in this chapter address the IBM compatible computers.

An IEEE-488 GPIB interface (built in, or add-in peripheral card) with appropriate driver software. The National Instruments GPIB IEEE-488.2 interface is assumed for all examples in this chapter.

Appropriate software (any of the following):

• Microsoft QuickBASIC, version 4.0 (or later)

• Microsoft “C”, version 5.1 or later, or Quick C, version 2.5.

• Any other programming language, or application software,

that supports the IEEE 488 GPIB interface (Pascal, Fortran, etc.).

A GPIB cable (preferably 2 meters long).

372XXB GPIB PM 2-3

EQUIPMENT AND MODEL 372XXB CONFIGURATION PROGRAMMING

To: IEEE 488.2 Interface

From: IEEE 488 Interface card connector

Figure 2-1. Model 372XXB Shown Connected to an IEEE 488.2 Controller

NOTE

The IBM PC and National Instruments GPIB interface were chosen for demonstrating the 372XXB GPIB operation in this manual. Any other GPIB controller that conforms to the IEEE 488 standard can be used to interface to the 372XXB.

connector

D spay

Pr nt er O ut

CRT Degaus s CRT Br t

Configuration Configure the 372XXB as shown in Figure 2-1. Apply power to the

372XXB and allow the system software to load from disk. Once the software has finished loading and start-up testing is complete, the

10 M Hz Re f

372XXB is ready to be remotely controlled via the GPIB. It is important to note that the 372XXB will not respond to GPIB commands un-

VG A O UT

Ex te rn a I/ O

Re ference Exte nson

Bas Fuses

Po r t 1 Po r t 2

RAO u t

RA I n RB I n RB O u t

til the 372XXB system software has been loaded.

Connect a GPIB cable from the computer/controller to the rear panel IEEE 488.2 GPIB connector(left).

Apply power to the computer/controller and load the appropriate pro-

Connect here

Do not connect here

Dis play

gramming language software (QuickBASIC, “C”, etc.).

The default GPIB address for the 372XXB (6) is assumed for all examples in this chapter.

2-4 372XXB GPIB PM

MODEL 372XXB GPIB PROGRAMMING PROGRAM ELEMENTS

2-3

GPIB PROGRAM ELEMENTS

National

Instruments

GPIB Interface

The discussions in this chapter demonstrate basic GPIB programming concepts that are typical elements of most GPIB application programs.

The controller used to demonstrate these concepts is the National Instruments 488.2 GPIB Interface which will be referred to as NI488 throughout this chapter.

NOTE

Regardless of the controller used, consult its documentation and software distribution disks for complete details and examples on setup and use of the controller’s hardware and interface software functions.

Throughout this chapter references will be made to variables, constants, and controller function calls declared in the NI488 file that your application uses to interface to the GPIB controller. This file is decl.h for C and qbdecl.bas for QuickBASIC, and it must be included in your GPIB program. Consult your documentation for the files used for other environments.

Including and compiling the appropriate NI488 file when preparing your application is what allows use of the NI488 GPIB interface procedures and function calls in your program. Also, the file named gpib.com must be installed in memory upon bootup of your computer. Typically, access to this file is through your system configuration file (that is, config.sys for DOS based computers).

The g pi b.com is what allows your GPIB program to physically inter- face to the installed GPIB controller and to execute GPIB function calls during operation.

NOTE

Consult your controller’s documentation for complete details on software and hardware setup, test, and use prior to proceeding with the following discussion. Knowledge of your controller and its operation will be assumed from this point forward.

Definitions The following definitions apply for the remainder of this chapter:

board = 0, Active controller board number address = 6, GPIB address of the instrument. Address List = addresList, list of GPIB addresses terminated

with the NI488 constant NOADDR. For our examples the list consists of two elements (6, NOADDR).

372XXB GPIB PM 2-5

INITIALIZING MODEL 372XXB THE GPIB PROGRAMMING

2-4

INITIALIZING THE GPIB

Initializing is the process of directing your controller to take control of the bus (become CIC — Controller In Charge) and setting the GPIB software to initial default settings.

NOTE

Default initial installation configuration is assumed for the NI488 hardware and software.

NI488 does this by sending an interface clear to the desired board using:

SendIFC(board)

The board will become CACS (Active controller). NI488 software allows use of up to 4 controllers. The board specified by the SendIFC() function must be designated CIC – Controller In Charge in its setup and configuration. See NI488 config utility in NI488 documentation.

SendIFC() is also useful anytime you want to insure that your GPIB controller has control over the bus, the GPIB software is in its default parameters, and GPIB of all instruments on the bus is cleared and in idle state.

The following NI488 functions are also useful when initializing your application.

2-5

SHUTTI NG DO WN T HE GPIB SYSTEM

To place all instruments in remote state, use:

EnableRemote(board, addressList)

To clear GPIB operation of all instruments use:

DevClearList(board, addressList)

An important step in quitting a GPIB application is to shut down the GPIB interface. For the NI488 this is done by

Insuring that you have control over the bus. Clearing all instruments’ GPIB and placing them in an idle state. Releasing the controller GPIB software and hardware.

Implement the above by sending:

SendIFC(board) ibonl(board, 0)

2-6 372XXB GPIB PM

MODEL 372XXB DETECTING PROGRAMMING GPIB ERRORS

2-6

DETEC TING GP IB ERRORS

Full Error Detection Full error detection and handling is an invaluable debugging tool that

Limited Handling

Error Detection

NI488 Global

Variables

It is important to use error checking code throughout your application program. Error checking usually does not significantly impact the speed of a GPIB application. This is because the GPIB bus operations are I/O operations whose execution time depends on a handshake process. This process is typically much slower than executing (error checking) code in your computer’s memory.

should be used to its fullest during development of your application.

Error detection with at least a limited amount of handling should be used after each GPIB I/O operation in your final program. This will insure predictable operation of your application, proper system control, and accurate data processing.

The NI488 interface maintains three global variables useful in determining correct GPIB operations. These variables are updated after, and reflect the condition of, the last GPIB call to the interface. The variables are:

IBSTA

This variable provides the latest bus activity status; that is, errors, completions, time outs, etc.

IBERR This variable provides information on the type of error, if an error was reported in IBSTA.

IBCNT/IBCNTL

The number of data bytes transferred on the bus in the last operation. IBCNTL is the “long integer” version of IBCNT.

Example Error checking for the NI488 interface is as follows. After each GPIB

call, the IBSTA is checked for errors using the NI488 declared constant EERR - in BASIC, or ERR in C. If true, the gpiberr() function is called to decode and display the global variables IBS TA, IBERR, and IBCNT. For example, for QuickBASIC, the following code is inserted after a GPIB call:

IF IBST A% AND EERR THEN CALL gpiberr(“Error during GPIB operation.”) END IF

NOTE

The NI488 disks and documentation contain the source listing of the gpiberr() function. This function should be copied into your code and used after each GPIB function call. Use the example programs provided on the NI488 distribution disks. Note that gpiberr() can also be modified to fit a particular application’s requirements.

372XXB GPIB PM 2-7

SETTING GPIB MODEL 372XXB OPERATION TIME OUT PROGRAMMING

2-7

SETT ING GPIB OPERATION TIME OUT

Example The NI488 time out is set using the ibtmo() interface call, as follows:

Setting GPIB time out is necessary to allow for lengthy instrument operations to complete before the application program continues with its processing. (Refer to paragraph 2-1, Waiting for Instrument Operations to Complete.)

ibtmo(instrument_handle, timeout_setting)

Where:

instrument_handle = The value returned by the ibfind() or ibdev() interface call for the instrument.

timeout_setting = A value that disables or sets the time out setting. NI488 uses declared constants to represent the allowable time out settings, for example, the T100s constant is 100 seconds, T30ms is 30 milliseconds, TNone is 0, etc. The complete list is in the NI488 include file for your language (qbdecl.b a s, decl .h ).

NOTE

Consult NI488 documentation and distribution disks for information and an example on using ibtmo() , ifbind(), and ibdev().

2-8 372XXB GPIB PM

MODEL 372XXB SENDING PROGRAMMING COMMANDS

2-8

SENDING COMMANDS

GPIB controllers provide for sending GPIB commands to an instrument (or the controller itself if its address is used). The NI488 uses several commands, the most common is:

Send (board, address, buffer , numByt es, eot_mode)

Where:

board, address = see section 2-3 for definitions. buffer = String of one or more instrument specific GPIB com-

mands from the defined list in the instrument’s GPIB documentation.

buffer = String of one or more instrument specific GPIB commands from the defined list in the instrument’s GPIB documentation.

numBytes = The number of bytes contained in the buffer. eot_mode = The method used to signal end of transmission. This

is typically done using ASCII linefeed character 0A hex (10 deci- mal) and then setting EOI state (end of transmission) on the bus. The NI488 defines the following constants for use to setup end of transmission methods:

NLend - linefeed with EOI DABend - EOI only NULLend - Do nothing to mark end of transmission

Example: Send the 372XXB at address 6, the commands “CH2;DSP;MAG”, from

372XXB

Commands Used

controller number 0, using the linefeed with EOI to mark the end of transmission:

Send (0, 6, “CH2;DSP;MAG”,1 1,NLend)

The above example uses the following commands defined in the 372XXB command set:

CH2 – sets active channel to 2, DSP – displays only the active channel on the whole screen, MAG – displays the active channel’s data in log magnitude format

(dB).

NOTE

The semicolon (;) is used to separate the different commands.

372XXB GPIB PM 2-9

RECEIVING DATA MODEL 372XXB FROM AN INSTRUMENT PROGRAMMING

2-9

RECEIVING DATA FROM AN INSTRUMENT

In order to receive data from an instrument over the GPIB, you must first instruct the instrument to output the desired data. You do this by using one of the instrument’s defined data output commands and the controller Send() function (see paragraph 2-8, “Sending commands”).

The instrument must then be given permission to start sending data (talk). The NI488 call to do this is:

Receive(board, address, buffer, numBytes, eod_mode)

Where:

board, address = see section 2-3 for definitions. buffer = The name of the memory address of the buffer where the

received data is to be placed. Typically this is an array of type characters (a string). Although, for binary data transfers, the NI488 software will accept an array of almost any type; that is. integer, floating point, etc.

numBytes = The maximum number of bytes to read from the instrument. Insure that “buffer” above is of at least this size.

eod_mode = The method used to signal the controller to stop receiving data. Typically the NI488 constant STOPend is used (EOI state – end of transmission – set with the last byte). If you want to stop receiving when a certain transmission terminator character is received, then use the hex value of that character instead of the ST OPend.

Example: Use the NI488 controller number 0, to send the 372XXB at address 6,

the command “ONP” using the line feed with EOI to mark end of trans- mission:

Send(0, 6, “ONP”, 3, NLend)

Upon receiving a data output command, the 372XXB will prepare the data requested and wait for the controller to put it in the talk state so it can put the data out on the bus. This is done by:

numBytes = 20 Receive(0, 6, buffer, numBytes, STOPend)

Error Handling: The number of bytes actually sent on the bus can now be retrieved

from the NI488 interface software by immediately storing the value of

the IBCNT global variable in a program variable as follows:

actualReceivedBytes = IBCNT

2-10 372XXB GPIB PM

MODEL 372XXB SRQ PROGRAMMING HANDLING

If we expected an exact number of bytes to be received, we can compare the requested number of bytes “numBytes” with the actual received “act ualRec eievedByt es” and take some corrective action if they do not match. You should do this before continuing to the data processing section of the program:

If numBytes ISNOTEQUALTO actualReceivedBytes then Call gpiberr(“incorrect number of bytes

received”) END IF

NOTE:

Consult your programming language syntax for the operator used to check in-equality, to use in place of ISNOTEQUALTO.

2-10

Commands Used

SRQ HANDLING

Calculating the

Binary Weighted

Bit Value

Enabling Service

Example Command the 372XXB to request service, i.e. generate an SRQ, when

372XXB

Request

The above example uses the following commands defined in the 372XXB command set:

ONP – Outputs the number of data points in the current sweep. It will output the number represented in ASCII format.

Controllers use a dedicated line on the GPIB to detect if an instrument has requested service. An instrument sets this line when a predetermined set of conditions inside it have been met. These conditions are selected and programmed into the instrument by setting the Service Request Enable Register to a decimal value that corresponds to the bit values which, when true, will generate an SRQ. This is a binary weighted decimal value in the range 0 – 255.

The decimal value of a bit in a register is equal to the number 2 raised to a power equal to the bit number. For example, the decimal value of bit 4 in the Service Request Enable Register is 2 raised to the power 4 which is: 2

To enable service request in the 372XXB, use the command *SRE Service Request Enable, with the desired value.

it has data to send, then output the number of points in the current sweep. We need to enable bit 4 (MAV), Message Available, in the Service Request Enable Register, so a service request will be generated when the data is ready. The decimal value of bit 4 is 16 (2

= 16. Similarly, the decimal value of bit 0 is: 20 = 1.

= 16).

The NI488 Send() function is used to send the 372XXB at address 6, the commands “ *SRE 16;ONP” (12 ASCII bytes), from controller num- ber 0, using the linefeed with EOI to mark end of transmission:

Send(0, 6, “*SRE 16;ONP”, 12, NLend)

372XXB GPIB PM 2-11

SRQ MODEL 372XXB HANDLING PROGRAMMING

Commands Used The above example uses the following commands defined in the

372XXB command set:

*SRE – Sends a Status Request Enable mask. ONP – Outputs the number of sweep points.

NI488

SRQ Functions

The following NI488 functions are useful in handling SRQ operations. Consult your NI488 documentation for full details.

To test for occurrence of SRQ:

TestSRQ(board, SRQset)

Where:

• SRQset contains 1 if SRQ is set, or 0 if it is not.

To wait for occurrence of SRQ and report if it was set:

WaitSRQ(board, SRQset)

Where:

• SRQset contains 1 if SRQ was set within the time out

allowed, or 0 if it was not. (See paragraph 2-8, Setting GPIB Operation Time Out.)

To find out which instrument is requesting service (set SRQ), instruct the controller to perform a serial poll and return the results as follows:

FindRQS(board, addressList, statusByt e )

Where:

• statusByte = The status byte of the first requester found is

returned in this variable.

• The index in addressList that contains the address of the in- strument requesting service is returned in the IBCNT global variable.

To read out the SRQ byte from an instrument:

ReadStatusByte(board, address, statusByte)

To parallel poll, see the following functions in the NI488 documentation.

PPoll() PPollConfig() PPollUnconfig()

2-12 372XXB GPIB PM

MODEL 372XXB WAITING FOR INSTRUMENT PROGRAMMING OPERATIONS TO COMPLETE

2-11

WAITING FOR INSTRUMENT OPERATIONS TO COMPLETE

Example 1 Command the 372XXB to perform a sweep and hold then place an AS-

Instruments often require a period of time to complete certain operations such as disk I/O, measurement sweep, data preparation, etc.. Your application program must allow the instrument time to complete these operations and be able to detect when operations are completed.

The simplest mechanism for synchronizing operations over the GPIB involve using the *OPC? - Operation Complete query and the *OPC Operation Complete command.

CII “1" in its output buffer (*OPC?) when done. The NI488 Send() function is used to send the 372XXB at address 6,

the commands, “TRS;WFS;HLD;*OPC?”, from controller number 0, us- ing the linefeed with EOI to mark end of transmission. The Receive() function is then used to hold the program from continuing processing until it receives the output of the *OP C command (or times out):

buffer = “TRS;WFS;HLD;*OPC?” Send(0, 6, buffer, 17, NLend) oneByte = 1 Receive(0, 6, buffer, oneByte, ST OPend)

NOTE

The time out must be set high enough to allow the sweep to complete (see “Setting time outs” in paragraph 2-8).

Example 2 Now we will modify the above example to request service when bit 4

(MAV) in the Status Byte Register is set (*SRE 16) to let the program know when the *OPC? data is ready to be output. This overcomes the time out problem but it does increase program complexity.

buffer = “*SRE 16;T RS;W FS;HL D;*O PC? ” Send(0, 6, buffer, 25, NLend) SRQset = 0 WHILE (SRQset = 0)

WaitSRQ(board, SRQset) ReadStatusByte(board, address , statusBy te) oneByte = 1 Receive(0, 6, buffer, oneByte, ST OPend)

NOTE

TestSRQ() can be used instead of WaitSRQ( ) to check for the occurrence of SRQ in the WHILE loop. This would allow your program to perform other tasks while waiting for SRQ inside the WHILE loop.

372XXB GPIB PM 2-13

WAITING FOR INSTRUMENT MODEL 372XXB OPERATIONS TO COMPLETE PROGRAMMING

372XXB

Commands Used

Examples 1 and 2 above used the following commands defined in the 372XXB command set:

*SRE - sends a Status Request Enable value. TRS - triggers a sweep WFS - waits one full sweep HLD - goes into hold mode *OPC? - outputs an ASCII “1" w hen o perati on is

complete

NOTE:

Refer to Chapter 7, Remote Only Operations for more information and examples on status reporting and service request generation.

2-14 372XXB GPIB PM

Chapter 3 Model 372XXB Programming Examples

Table of Contents

3-1 INTRODUCTION . . . . . . . . . . . . . . . . . . 3-3

3-2 372XXB PROGRAMMING EXAMPLES . . . . . . 3-3

3-3 EXAMPLE 1: BASIC OPERATIONS . . . . . . . . 3-4

3-4 EXAMPLE 2: 12 TERM CALIBRATION . . . . . . 3-6

3-5 EXAMPLE 3: CALIBRATION DATA TRANSFER . 3-8

3-6 EXAMPLE 4: ASCII STRING TRANSFER . . . . . 3-10

3-7 EXAMPLE 5: DISK OPERATIONS . . . . . . . . 3-11

3-8 EXAMPLE PROCEDURE,

WaitForInstr() . . . . . . . . . . . . . . . . . . . . 3-12

3-9 EXAMPLE FUNCTION,

GetNumBytes(address, headerstring) . . . . . . . 3-13

3-10 EXAMPLE PROCEDURE,

TakeCalData() . . . . . . . . . . . . . . . . . . . . 3-14

Chapter 3 Model 372XXB Programming Examples

3-1

3-2

INTRODUCTI ON

372XXB PROGRAMMING EXAMPLES

This chapter contains example programs to familiarize the user with 372XXB programming. Familiarity with manual (front panel) operation of the 372XXB is assumed. (Throughout this section, the 372XXB VNA is referred to simply as “372XXB”.) A complete description of front panel operation is contained in the 372XXB Vector Network Analyzer System Operation Manual.

Also, it is assumed that you have read Chapters 1 and 2 and are familiar with the information they contain. This information describes the various syntax and functions used in the example sequences presented throughout the chapter. This includes: Send, Receive, IBCNT, IBERR, ISNOTEQUALTO, and others.

The main sequences for five example 372XXB programs are listed and explained in the following pages. In these examples, the NI488 function calls are abbreviated; refer to Chapter 2 and the NI488 documentation for full details. Refer to the 372XXB Command Function groups and the Command listings in this manual for complete details on 372XXB command operations.

NOTE

The functions and procedures called from the example sequences in paragraphs 3-3 through 3-7 are provided at the end of this chapter in paragraphs 3-8 through 3-10.

The intent of these example program sequences is to provide algorithms useful when programming various features of the 372XXB. You are encouraged to study these algorithms, copy them into your programming environment, and tailor them for your language and application.

372XXB GPIB PM 3-3

EXAMPLE 1: MODEL 372XXB BASIC OPERATIONS PROGRAMMING EXAMPLES

3-3

EXAMPLE 1: BASIC OPERATI ONS

This example sequence lists and explains some common 372XXB operations.

Setup display and sweep frequencies

Send “CH2;DSP;MPH;SRT 40 MHZ;STP 20 GHZ”

Setup markers

Send “MK1 40 MHZ;MK2 20 GHZ”

Read and store current instrument setup

Request instrument setup string

Send “OFP”

Read instrument setup string

Receive(instrSetup, MAXSIZE, STOPend)

Get number of bytes transferred

sizeInstrSetup = IBCNT

NOTE

Program variables instrSetup and sizeInstrSetup will be used later with the IFP command to input the saved setup string.

Read sweep frequencies

Trigger and wait for full sweep then hold

Send “TRS;WFS;HL D”

Wait for operations to complete (See “Wait for Instr()” example, page 3-14.)

WaitForInstr()

Request sweep frequencies (OFV): Use floating point (64 bit) binary format (FMB), Least Significant Byte first ordering (LSB for IBM/compatible PCs only).

Send “LSB;FMB;O FV ”

Get number of bytes to read: See Chapter 7, “Data Transfer” section for details on <Arbitrary Block> data transfers and structure of the header used to precede and give number of bytes in data block. (See “GetNumBytes( )” example, page 3-15.)

numBytes = GetNumBytes(address, headerString)

Read frequencies freqArray is a floating point double precision array of up to 1601 elements.

3-4 372XXB GPIB PM

MODEL 372XXB EXAMPLE 1: PROGRAMMING EXAMPLES BASIC OPERATIONS

Receive(freqArray, numBytes, STOPend)

Check for complete transfer

if (numBytes ISNOTEQUALTO IBCNT then

gpiberr(“Could not read freq list correctly”)

Reset instrument

Send reset command

Send “*RST”

Wait for operations to complete (page 3-14)

Wa itForIns tr()

Download and restore a previously saved setup

Command instrument to receive a setup string. Use “NULLend” (see Chapter 2, paragraph 2-9.)

Send “IFP ”

NOTE

The space after the IFP command is needed to separate it from the setup string, which follows.

Send the setup string. Use “NLend” (see Chapter 2, paragraph 2-9.)

Send(instrSetup, sizeInstrSetup)

Check if all data was sent correctly

if (sizeInstrSetup ISNO TEQUA LTO IBCNT then

gpiberr(“Error sending setup string”)

Select instrument Marker 1 active

Send “MR1”

Read measurement trace

Trigger and wait for full sweep then hold

Send “TRS;WFS;HL D”

Wait for operations to complete (page 3-14)

WaitForInstr()

Request trace data: in final trace graph type values (OFD), in floating point (32 bit) binary format (FMC). Use Least significant Byte first ordering (LSB, for IBM/compatible PCs only)

Send “LSB;FMC;O FD”

372XXB GPIB PM 3-5

EXAMPLE 2: MODEL 372XXB 12 TERM CALIBRATION PROGRAMMING EXAMPLES

Get number of bytes to read (page 3-15)

numBytes = GetNumBytes

Read out the trace data values.

Receive(traceData, numBytes, STOPend)

Check if all data was transferred

if (numBytes ISNOTEQUALTO IBCNT then

gpiberr(“Could not receive data.”)

Calculate number of sweep points in data string POINTSIZE is 8 bytes for data transfers using the FMB format and 4 bytes if using the FMC format. See Chapter 7, “Data Transfer Commands.”

numFreqs = numBy tes / POINT SIZ E

Put instrument(s) in local to allow use of front panel

EnableLocal(board, addressList)

3-4

EXAMPLE 2: 12 TERM CALIBRATION

This example sequence lists and explains 372XXB commands used for automated 12 Term Calibration.

Display instructions to operator on computer screen

PRINT “Install 33KF KF Phase Equal I nsert a ble on Port 1” PRINT “Install 3670K502 Thru Line female side to Port 2” PRINT “so the new Port 2 is the male end of the thru” PRINT “Shape the end of the thru so it is near Port 1” PRINT “(Press a key when ready)”

Set up calibration parameters

Send “SCM;LTC;C12;ISN”

Set up calibration frequencies

Send “DFC;FRS 1 GHZ;FRI 100 MHZ;F RP 41; FIL;DFD”

Set up connectors and loads

Send “P1C;CFK;P2C;CMK;BBL”

Begin calibration data collection

Send “BEG”

Wait for operations to complete (page 3-14)

Wait For Inst r()

3-6 372XXB GPIB PM

MODEL 372XXB EXAMPLE 2: PROGRAMMING EXAMPLES 12 TERM CALIBRATION

Instruct operator via the controller screen... To connect ISOLATION DEVICES between Ports 1 and 2 and wait for him; then measure devices. (See TakeCalData(), pg 3-14).

PRINT “Connect ISOLATION DEVICES between Ports 1 and 2" PRINT “Press ENTE R when ready” TakeCalData()

Instruct operator via the controller screen....

To connect BROADBAND LOADS between Ports 1 and 2 and wait for him; then measure devices.

PRINT “Connect BROADB AND LO ADS between Ports 1 and 2. PRINT “Press a key when ready” TakeCalData()

Instruct operator via the controller screen....

To connect OPEN to Port 1 and SHORT to Port 2 and wait for him; then measure devices.

PRINT “Connect OPEN to Port 1 and SHORT to Port 2 PRINT “Press a key when ready” TakeCalData()

Instruct operator via the controller screen....

To connect SHORT to Port 1 and OPEN to Port 2 and wait for him; then measure devices.

PRINT “Connect SHO RT to Port 1 and OPEN to Port 2 PRINT “Press a key when ready” TakeCalData()

Instruct operator via the controller screen....

To connect Port 1 and Port 2 with the reminder to NOT INSTALL ADDITIONAL THRU LINES/ADAPTERS BETWEEN PORTS, and wait for him; then measure devices.

PRINT “Connect Port 1 and Port 2 but DO NOT INSTALL ADDITIONAL T HRU LINES/ADAPTERS BETWEEN PORTS PRINT “Press a key when ready” TakeCalData()

372XXB GPIB PM 3-7

EXAMPLE 3: CALIBRATION MODEL 372XXB DATA TRANSFER PROGRAMMING EXAMPLES

3-5

EXAMPLE 3: CALIBRATION DA TA TRANSFER

This example sequence lists and explains 372XXB commands for transferring calibration error terms/coefficients.

Setup a Frequency Response Transmission Calibration.

Set up calibration parameters

Send “SCM;LTC;CFT”

Set up calibration frequencies

Send “DFC;FRS 1 GHZ;FRI 100 MHZ; FRP 41; FIL;DFD”

Begin calibration data collection

Send “BEG”

Wait for operations to complete (page 3-14)

Wa itForIns tr()

Instruct operator via the controller screen... To connect THRU LINE between Ports 1 and 2 and wait for him.

PRINT “Connect THRU LINE bet ween Ports 1 and 2" PRINT “Press ENT ER when ready”

Measure thruline (page 3-14).

TakeCalData()

Read Calibration Coefficient Data from instrument and store the 488.2 data transfer header which is useful for sending the same size data array back to the 372XXB later. Also calculate and store the number of frequency points read in.

Request the error term/coefficient array (OC1) in 64 bit Floating Point format (FMB), Least Significant Byte order (LSB, for PCs only). See Chapter 7, “Data Transfer Commands” for the error terms returned by the OCx series commands.

Send “LSB;FMB;O C 1”

Get number of bytes contained in the data string and store the header read from the 372XXB into calHeader (string of characters). See GetNumBytes(), page 3-13.

numBytes = GetNumBytes(address, calHeader)

Read calibration data values calData is an 82 element double precision floating point array.

Receive(calData, numBytes, STOPend)

3-8 372XXB GPIB PM

MODEL 372XXB EXAMPLE 3: CALIBRATION PROGRAMMING EXAMPLES DATA TRANSFER

Check if all data was transferred

if (numBytes ISNOTEQUALTO IBCNT) then gpiberr(“Could not receive data.”)

Store number of calibration data bytes transferred

calDataSize = IBCNT

Calculate number of frequency points in the data trace if desired. POINTSIZE is 8 bytes for data transfer using the FMB format. See Chapter 7, “Data Transfer Commands.” The division by two is because each data point represents a complex data pair (real, imaginary).

numFreqs = (CalDataSize / 2) / POINTSIZE

Send Calibration Coefficient Data to instrument

Simulate a Transmission Calibration Command the 372XXB to apply transmission calibration coefficients to data (AFT), then input the calibration coefficient array for transmission error term (IC1), in 64 bit Floating Point format (FMB), Least Significant Byte order (LSB, for use with PCs only). Use “NULLend” (see Chapter 2, paragraph 2-9.)

Send “AFT;LSB;FMB;IC1 ”

NOTE

Note the space after the IC1 command; it is needed to separate it from the calibration coefficient data array, which follows.

Send cal coefficient #1 data transfer header (same one that was received from the OC1 transfer). Use “NULLend” (see Chapter 2, paragraph 2-9.)

calHeaderSize = LENGTHOFSTRING(calHeader) Send(calHeader, calHeaderSize, NULLend)

NOTE

Consult your compiler documentation for a function that returns length of a string.

Check for proper transfer

if (CalHeaderSize ISNOTEQUAL T O IBCNT ) then gpiberr(“Data not sent properly”)

Send cal coefficient #1 data. Use “NLend” (see Chapter 2, paragraph 2-9.)

Send(calData, calDataSize)

372XXB GPIB PM 3-9

EXAMPLE 4: ASCII MODEL 372XXB STRING TRANSFER PROGRAMMING EXAMPLES

Check for proper transfer

if (calDataSize ISNOTEQUALTO IBCNTl then gpiberr(“Data not sent properly”)

Wait for operation to complete (page 3-14)

WaitForInstr()

Turn on/apply error correction

Send “CON”

3-6

EXAMPLE 4: ASCII STRING TRANSFER

This is an example sequence showing data string input to the 372XXB. The string sent below is used to set hardcopy data output labels.

The 372XXB requires the double quote characters (“ ”) to delimit ASCII strings being sent to it. That is, to send a string called mystring you would actually send gramming languages also delimit a character string with double quotes. In order to send the 372XXB a quote ( “ ) as a regular character, you must precede it with the backslash (\) character in the C language and with a quote character (“) in BASIC.

A 372XXB ASCII string may also be delimited using a single quote character ( ′ ) at the beginning an end of the string. In which case, the backslash (\) for C and the double quote (“) in BASIC are not required.

Define DUT Model in the data label. The following command sequence needs to be sent to the 372XXB:

LMS “4_8_FILTER”

If using C use this syntax

Send

“

LMS \”4_8_FILTER\”“

“

mystring“. This presents a problem since pro-

NOTE

If using BASIC use this syntax

Send “LMS ““4_8_FILTER”””

Here the same command sequence can be sent with the single quotes (’ ’) without the need for additional character as above.

Send “LMS ’4_8_FILTER’”

If shutting down the GPIB immediately after this series of commands, then you must also make the controller wait for the 372XXB to completely receive this data before shut down.

Wa itForIns tr()

3-10 372XXB GPIB PM

MODEL 372XXB EXAMPLE 5: PROGRAMMING EXAMPLES DISK OPERATIONS

3-7

EXAMPLE 5: DISK OPERATIONS

This example sequence lists and explains 372XXB commands for 372XXB internal disk operations.

Sweep, and store channel 1 trace data to memory

Send “CH1;S11;CH3;S 21;W FS;CH1;ST D ”

Store trace memory data to hard disk The following command sequence needs to be sent to the 372XXB:

Send “SAVE ’C:\CH1_S21.NRM’”

Wait for operations to complete (page 3-12)

WaitForInstr()

Output channels 1 Tabular Data to instrument floppy disk

Send “SA VE ’A: \CH1_S21.D AT’”