Anritsu 360 Programming Manual

360 VECTOR NETWORK ANALYZER

GPIB PROGRAMMING MANUAL

Software Version 3.07

490 JARVIS DRIVE ● MORGAN HILL, CA 95037-2809

P/N: 10410-00070

REVISION: A

COPYRIGHT 1991 WILTRON CO.

PRINTED: MAY 1991

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.

CONTENTS

Tab / Section Title

1 General GPIB Information

This section describes the manual and contains a brief description of the GPIB hardware and
the GPIB data transfer and control functions. It also describes the 360 VNA GPIB interface
function subset capability and response to IEEE-488 interface function messages.

2 Introduction to GPIB Programming for the 360 VNA

This section contains a brief introduction to GPIB programming techniques and describes
procedures to be used when preparing GPIB programs for the 360 VNA. It includes informa­tion about 360 GPIB command syntax, programming tips and example programs.

3 Commands for Basic Front Panel Operations

This section describes the 360 VNA GPIB commands that control the basic test and measure­ment functions a ssociated w ith fron t panel co ntrols and men u s. The comman d de scription s are
grouped by control function, for example: Data Entry Commands, Hard Copy Commands, etc.

4 Commands for Calibration Functions

This section describes the 360 VNA GPIB commands used to perform system calibration
functions. As in Section III, the command descriptions are grouped by control function.

5 Advanced GPIB Programming and GPIB Unique Functions

This section describes the 360 VNA GPIB commands that produce operations that are unique
to the GPIB mode of operation. Example commands included are: Data Transfer commands,
Group Execute commands, etc. As in the previous sections, the command descriptions are
grou ped b y cont rol funct ion .

6 Supplements

Included behind this tab are two application notes that contain information about GPIB
programming for the 360 VNA:

AN360-8, Programming the Model 360 Vector Network Analyzer Using Microsoft C

AN360-9, Programming the Model 360 Vector Network Analyzer Using HP Basic

7 GPIB Command Function Index

This index lists the GPIB commands for the 360 VNA by function. The paragraph number and
page number for each of 28 GPIB command function categories are reference in this index.

8 GPIB Quick Reference Guide

This Quick Reference Guide is an alphabetical list of the GPIB commands for the 360 VNA.
The listing for each command includes a brief description of the command function and
attributes (such as associated parameters). This document is also an alphabetical index to the
360 Vector Network Analyzer GPIB Programming Manual. The listing for each command
includes a reference to the paragraph in the programming manual that includes the complete
description of the command.



Part No. 11410-00038

Part No. 11410-00039

Microsoft C is a registered trademark of Microsoft Corporation.

360 GPIB PM i/ii

SECTION I

GENERAL GPIB INFORMATION

Table of Contents

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

Relationship of This Manual to Other 360 VNA Manuals . . . . . . . . . 1-3

How to Use This Ma nual . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Command Categories Used in This Manual . . . . . . . . . . . . . . . . . 1-4

1-2 DESCRIPTION OF THE IEEE-488 (IEC-625) INTERFACE BUS . . . . . 1-4

IEEE-488 Hardware Interface . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Data Byte Transfer Control Bus Description . . . . . . . . . . . . . . . . 1-4

IEEE-488 Interface Functions and Protocols . . . . . . . . . . . . . . . . 1-6

IEEE-488 Message Types . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1-3 360 VNA GPIB OPERATION . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Setting Default GPIB Operating Parameters . . . . . . . . . . . . . . . . 1-8

Response to GPIB Interface Function Messages . . . . . . . . . . . . . . 1-8

360 VNA Response To GPIB Error Conditions . . . . . . . . . . . . . . . 1-8

360 GPIB PM 1-1/1-2

SECTION I

GENERAL GPIB INFORMATION

1-1 INTRODUCTION

This manual describes remote operation of the WIL­TRON 360 Vector Network Analyzer usin g IEEE-488
Interface Function Messages and 360 GPIB Com­mands (i.e., Product Specific Commands). The soft­ware version supported by this manual is Version

3.07.
Included is a description of the IEEE-488 General

Purpose Interface Bus (G PIB) hardwar e and the bu s
data transfer and control functions. Also includ ed is
a brief intr oduction to GPIB pr ogrammin g, inclu ding
considerations for preparing GPIB programs for the
360 Vector Network Analyzer (VNA). All 360 VNA
GPIB commands currently used are listed and de­scribed.

The information about the IEEE-488 interface bus
presented in this manual is general in nature. For
complete and specific information, refer to the
ANSI/IEEE Std 488-1978 document entitled “IEEE
Standard Digital Interface for Programmable
Instrumentation”. This document precisely defines
the set of dedicated hardware signal lines, interface
functions, protocols, and messages for the interface
bus.

1-1.1 Relat ion ship of T his Man ual t o Ot her

360 VNA M anu als

This manual is intended to be used in conjunction
with the 360 Vector Network Analyzer System Op­eration Manual. Refer to that manual for general
information about the 360 VNA, including equip­ment set up and manual mode operating instruct­ions. Section I of that manual lists and describes all
360 VNA documen ta tion set manuals, including test
set and software manuals.

1-1.2 How t o Use This Manu al

Only information pertinent to 360 VNA GPIB pro­gramming is provided in this manual. Familiarity
with manual (front panel) operation of the 360 VNA

is assumed. System operating details are given in
this manual only if they are unique to the GPIB
operating mode, o r are diffe rent th an w hen oper ated
in the normal manual mode.

This section of the man ual descr ibes the manual an d
contains a brief description of the GPIB hardware
and the GPIB data transfer and control functions. If
you are already familiar with this material, this
section may be skipped. The remainder of the man­ual is organized as follows:

Section II — Introdu ction to GPIB Programming

•

for the 360 VNA — contains a brief introduction
to GPIB programming techniques and describes
procedures to be used when preparing GPIB pro­grams for the 360 VNA. If you are already famil­iar with this material, this section may be
skipped.

Sections III, IV and V — describe the 360 GPIB

•

commands used for Basic Front Panel Functions,
Calibration Functions and Advanced Program­ming/GPIB Unique Functions, respectively. The
programming information and tables containing
the command descriptions are grouped by func-
tion in these sections. Use this information as a
tutorial and for reference when preparing pro­grams.

The Functional Index Of Commands — lists the

•

360 GPIB commands by function and references
the paragraph, table and page number where the
descriptions for that group of commands are lo­cated in Sections III thru V.

360 GPIB Quick Reference Guide — This sepa-

•

rately bound document is located behind the last
section tab of this manual. It lists the 360 GPIB
commands alphabetically and references the loca-
tion in Sections III thru V of this manual where
information for each command is located. The list­ing in this guide for each command includes a
brief description of the command function and
associated parameters. Use this guide as a quick
reference when preparing programs.

360 GPIB PM 1-3

DESCRIPTION OF THE IEEE-488 (IEC-625) INT ERF ACE BUS I GENERAL INFORMATIO N

1-1.3 Command Categories Used in This

Manual

The 360 VNA GPIB interface responds to more than
400 commands to implement the set of 360 network
analyzer functions. For descriptive purposes, these
commands are organized into the following func­tional classifications:

a. Basic Front Panel Functions

These commands produce basic 360 VNA meas­urement operations identical to those produced
by the corresponding key functions on the 360
front panel. These commands are described in
Section III.

b. Calibration Functions

The set of calibration commands can be used to
set up the calibration parameters under pro­gram control and to guide an operator through
the 360 VNA calibration process. These com­mands are described in Section IV.

c. GPIB Unique Functions

These commands produce 360 VNA operations
that are unique to the GPIB mode of operation
or are operations that are best done using com­puter control of the system. They are described
in Section V.

1-2 DESCRIPTION OF THE IEEE-488

(IEC-625) INTERFACE BUS

The IEEE-488 General Purpose Interface Bus
(GPIB) is an instrumentation interface for integrat­ing instruments, computers, and other controllers
into systems. The bus uses 16 signal lines to effect
transfer of data and commands to all instruments
connected on the bus.

No more than 15 instruments may be connected to
the interface bus (however, a system may contain
more than one interface bus). The maximum total
accumulative cable length for one interface bus may
not exceed twice the number of instruments con­nected (in meters) , or 20 meters—whichever is less.

The instruments on the bus are connected in
parallel, as shown in Figure 1-1. Eight of the signal
lines (DIO1 thru DIO 8) are used for the transfer of
data and other messag es in a byte-se rial, bit-parallel
form. The remainin g eight lines ar e used for commu­nications timing (handshake), control, and status
information. Data are transmitted on the eight
GPIB data lines as a series of eight-bit characters,
referred to as bytes.

Data transfer is by means of an interlocked hand­shake technique (Figure 1-2). This technique
permits asynchronous communications over a wide
range of data rates. The following paragraphs
provide an overview of the data, and handshake
buses, and describe how these buses interface with
the 360 VNA.

1-2.1 IEEE-488 Hardware Interface

The IEEE-488 interface bus hardware implementa­tion is made up of 16 sign al lines that comp rise thr ee
functional groups; see Figure 1-1.

Data Bus (8 lines)

•

Data Byte Transfer Control Bus (3 lines)

•

General Interface Management Bus (5 lines)

•

The signal lines in each of the three groups are
designated according to function. Table 1-1 lists
these designations.

1-2.2 Data Byte Transfer Control Bus De-

scription

Control of information transfer on the GPIB data
Bus is accomplished by a technique called the “three­wire handshake”, which involves the three signal
lines of the Data Byte Transfer Control Bus. This
technique is described briefly below and is depicted
in Figure 1-2. For further information, refer to the
ANSI/IEEE Std 488-1978 document.

a. DAV (Data Valid)

This line goes TRUE (arrow 1) when the talker
has (1) sensed that NRFD is FALSE, (2) placed
a byte of data on the bus, and (3) waited an
appropriate length of time for the data to settle.

Table 1-1. Interface Bus Signal Line Designations

BUS TYPE SIGNAL LINE

Name Function

Data Bus DIO1–

DIO8

Data Byte
Transfer
and Control

General
Interface
Control

DAV
NRFD
NDAC

ATN
IFC
SRQ
REN
EOI

Data Input/Ou tput, 1 th ru 8

Data Available
Not Ready For Data
Not Data Accepted

Attention
Interface Clear
Service Request
Remote Enable
End Or Identify

1-4 360 GPIB PM

I GENERAL INFORMAT ION DESCRIPTION OF THE IEEE-488 (IEC-625) INT ERF ACE BUS

IEEE-488 BUS (16 Lines)

DEVICE A

Able to talk, listen,
and control

(e.g. EXTERNAL
COMPUTER)

DEVI CE B

Data Bus

(8 signal lines)

DATA LINES

Able to talk and listen

(e.g. 360 VNA)

DEVICE C

Only able to listen

(e.g. OTHER
INSTRUMENT**)

DEVIC E D

Only able to talk

(e.g. OTHER
INSTRUMENT**)

Data Byte
Transfer Contr ol

(3 signal lines)

HANDSHAKE Lines

General Interface
Management

(5 signal lines)

DATA INPUT/OUTPUT, DIO 1 thru DIO 8

Management
CONTROL Lines

DATA VALID

­NOT READY FOR DATA*

­NOT DATA ACCEPTED*

-

INTERFACE CLEAR

­ATTENTION

-

-

SERVICE REQUEST

-

REMOTE ENABLE

-

END OR INDENTIFY

NEGATION I S REPRESENTED

Note:

*

BY LOW STATE ON THESE
TWO LINES
IF USED

**

Figure 1-1. Interface Connections and Bus Structure

360 GPIB PM 1-5

DESCRIPTION OF THE IEEE-488 (IEC-625) INT ERF ACE BUS I GENERAL INFORMATIO N

b. NRFD (Not Ready For Data)

This line goes TRUE (arrow 2) when a listener
indicates that valid data has not yet been ac­cepted. The time between the events shown by
arrows 1 and 2 is var iable an d depen ds up on the
speed with which a listener can accept the infor­mation.

c. NDAC (Not Data Accepted)

This line goes FALSE to indicate that a listener
has accepted the current data byte for internal
processing. When the data byte has been ac­cepted, the listener releases its hold o n NDAC
and allows the line to go FALSE. However, since
the GPIB is constructed in a wired-OR configu­ration, NDAC will not go FALSE until all listen­ers participating in the interchange have also
released the line. As shown by arrow 3, when
NDAC goes FALSE, DAV follows suit a short
time later. The FALSE state of DAV indicates
that valid data has been removed; consequently,
NDAC goes LOW in preparation for the next
data interchange (arrow 4).

Arrow 5 shows the next action in time: NRFD
going FALSE after NDAC has returned TRUE.
The FALSE state of NRFD indicates that all
listeners are ready for the next information in­terchange. The time between these last two
events is variable and depends on how long it
takes a listener to p roce ss the data byte. In sum­mation, the wired-OR construction forces a
talker to wait for the slowest instrument to ac­cept the current data byte before placing a new
data byte on the bus.

1-2.3 IEEE-488 Interface Functions and Pro-

tocols

The IEEE-488 standard document describes a total
of 11 different possible interface functions. Each of
these interface functions acts in accordance with a
specific protocol defined in the standard. This set of
functions an d protocols define every possible manner
that information and control can be passed between
devices connected to the GPIB.

Specific instruments, such as the 360 VNA, are
implemented using only a portion, or subset, of the
total set of interface functions defined by the stand­ard. Table 1-2 lis ts the functional subset supported
by the 360 VNA.

Table 1-2. 360 VNA GPIB Interface Function

Subset Capability

Function
Identifier

AH1 Acceptor

SH1 Source

T6 Talker No Talk Only (TON)
TE0 Talker With

L4 Listener No Listen Only (LON)

LE0 Listen er Wi th

C0 Controller No Capability
SR1 Service Request Complete Capability
RL1 Remote/Local Complete Capability
PP1 Parallel Poll Complete Capability
DC1 Device Clear Complete Capability
DT1 Device Trigger Complete Capability
E1 Open Collector

Function 360 Capability

Complete Capability

Handshake

Complete Capability

Handshake

No Capability

Address Only

No Capability

Address Only

Complete Capability

Driver Electronics

1-2.4 IEEE-488 Message Types

There are three types of information transmitted
over t h e G PI B :

IEEE Interface Function Messages — These

•

messages are sent on the data lines and interface
management lines to control the state of the in­terface and the manner in which it responds to
commands. These messages are used to maintain
control of the interface. The user generally has
control over these signals; however, the extent of
user control is implementation-dependent and
varies with the specific hardware and software
used with the external controller.

Product-Specific Commands — These com-

•

mands are mnemonic codes sent by the external
computer to the 360 VNA to contr ol the setu p and
measurement operations of the 360 VNA. The
function and contents of these commands are not
specified by the IEEE-488 standard. They are
unique and specific to the WILTRON 360 VNA
and are described in Sec tio ns III , IV, and V of thi s
manual.

1-6 360 GPIB PM

I GENERAL INFORMAT ION DESCRIPTION OF THE IEEE-488 (IEC-625) INT ERF ACE BUS

These commands (also referred to as “360 GPIB
commands”) are transmitted over the data bus of
the GPIB interface to the 360 VNA in the form of
ASCII strings containing one or more codes. They
are decoded by the internal 360 VNA controller
and cause the various measurement functions of
the system to be performed. (The 360 VNA GPIB
interface doe s not dec od e these command s; it on ly
acts as the transmission channel to the internal
controller.)

Data and Instrument Status Messages —

•

These messages are sent by the 360 VNA to the
external computer via the GPIB. They contain
measurement data, setup information, or system
status information that the 360 VNA transmits
over the data bus in response to specific com­mands from the ex ter nal c ompu ter requ estin g the
data. The contents of these messages are specific
to the 360 VNA. They may be in the form of ASCII
strings, or binary data.

In some cases data messages will be transmitted
from the external computer to the 360 VNA. For
example, mess ages to load calibration data.

An SRQ (service request) is an interface function
message sent from the 360 VNA to the external
computer to request service from the computer,
usually due to some predetermined system condi­tion or error. To send this message, the 360 VNA
sets the SRQ bit of the General Interface Manage-

ment Bus true and then sends a status byte on
the data bus lines.

An SRQ interfac e function message is also sent by
the 360 VNA in response to a serial poll message
from the computer, or upon receiving either an

OEB or OPB command from the computer. The

protocols associated with the SRQ functions are
defined in the ANSI/IEEE Std 488-1978 docu­ment. The 360 GPIB commands for these func­tions along with the SRQ status byte format in­formation is contained in Paragraph 5-6 — SRQ
Status Bytes: Commands — in this manual.

The manner in which Interface Function Messages
and Product-Specific Commands are invoked in pro­grams is implementation specific for the GPIB inter­face used with the external computer. Even though
both message types are represented by mnemonics,
they are implemented and used in different ways.

The Interface Function Messages normally are sent
automatically by the GPIB driver software in re­sponse to invocation of a software function. For ex­ample, to send the
one would call the

SDC interface function message,

ibclr function of the National

Instruments software driver. On the other hand, the
360 GPIB command

RST is sent in a string message

to the addressed device (e.g. 360 VNA). In the case
of the National Instruments example, this would be
done by using the

ibwrt function call.

DAV

1

4

2

NRFD

3

5

NDAC

Figure 1-2. Typical GPIB Handshake Operation

FALSE (0/HIGH)

TRUE (1/LOW)
FALSE (0/HIGH)

TRUE (1/LOW)
FALSE (0/HIGH)

TRUE (1/LOW)

360 GPIB PM 1-7

360 VNA GPIB OPERATION I GENERAL INFORMATIO N

1-3 360 VNA GP IB O PER ATIO N

All of the front panel control functions of the 360
VNA, except for LINE ON/O FF, are controllable usin g
360 GPIB commands sent from the external com­puter. When in the GPIB operating mode, the 360
VNA functions as both a list ener and a talker (Ta­ble 1-2).

1-3.1 Setting Default GPIB Operating Pa-

rameters

The 360 VNA GPIB address value is set to 6 at t he
factory. This value may be changed via the GPIB
SETUP MENU (from the UTILITY MENU); refer to
Index A1 of th e 360 V ector Network Analy zer System
Operation Manual. The data delimiting terminator
is set as CR/CR-LF at the factory. This may also be
changed via the GPIB SETUP MENU.

1-3.2 Response to GPIB Interface Function

Messages

Table 1-3 lists the set of IEEE–488 Interface Func­tion Messages that the 360 VNA will rec ognize. W ith
the exception of the

DCL and SDC messages, these

messages affect only the operation of the 360 VNA
GPIB interface. The response of the 360 VNA GPIB
interface for each message is included in Table 1-3
(next page).

Interface function messages are transmitted on the
GPIB data lines and interface management lines as

either unaddressed or addressed commands. The
manner in wh ic h these messages are in vo ked in pro­grams is implementation dependent. For program­ming information, refer to the documentation in­cluded with th e GPIB Inte rface for the external co m­puter used.

1-3.3 360 VNA Response To GPIB Error

Condi tions

The following par agrap hs describe ho w the 360 VNA
responds to error conditions during the GPIB mode
of ope rat ion

a. Sy nta x Er ror

The 360 beeps and sends a Service Request
(SRQ) to the external computer (if SRQs are
enabled). The 360 also ignores any further
commands until it is programmed to talk or be
unlistened.

b. Parameter Out Of Range Error

Upon detec ting th is condition , the 360 move s the
cursor adjacent to the erroneous entry, beeps,
and displays the entry in red. It also sends an
SRQ (if enabled) to the external computer. The
error is cleared upon execution of the next in­struction.

c. Action Requested Not Possible

The 360 sends an SRQ (if enabled) to the exter­nal computer and ignores the command.

1-8 360 GPIB PM

I GENERAL INFORMAT I ON 360 VNA GPIB OPERATI O N

Table 1-3. 360 VNA Response to IEEE-488 Interface Function Messages

Interface
Function
Message

DCL
SDC

Message Function

Device Clear
Selected Device Clear

Addressed

Command

No

Yes

360 VNA Response

Resets the 360 to its default state. Equivalent to the RST

command.
GTL Go To Local Yes Returns the 360 to local (control panel) control.
GET Group Execute Trigger Yes Executes a string of commands defined by the DEF...END

mnemonics.

NOTE

The GET command is buffered and executed in­line with oth er c o mma nds .

IFC Interface Clear No Stops the 360 GPIB from talking/listening.
LLO Local Lockout No Disables the control panel RETURN TO LOCAL key
REN Remote Enable No Places the 360 in remote when addressed to listen
SPE Serial Poll Enable No Outputs the binary status byte
SPD Serial Poll Disable No Disables the serial poll function
PPC Parallel Poll Configure Yes Sets the assigned bus line to reflect its SRQ status
PPE Parallel Poll Enable Yes Enables the 360 for parallel poll operation
PPU Parallel Poll Unconfigure No Cancels any previous parallel poll configurations
PPD Parallel Poll Disable Ye s Disables the parallel polling function

Note:These are

included with the GPIB Interface for the external co mputer used .

not

Device Specific Commands. These messages are implementation dependent — refer to the documentation

360 GPIB PM 1-9/1-10

SECTION II

INTRODUCTION TO GPIB PROGRAMMING

FOR THE 360 VNA

Table of Contents

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

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

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

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Default GPIB Operating Parameters . . . . . . . . . . . . . . . . . . . . 2-3

2-3 360 GPIB PROGRAMMING BASICS . . . . . . . . . . . . . . . . . . . 2-4

360 GPIB Command Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Command Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Programming Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2-4 TYPICAL GPIB PROGRAM STRUCTURE . . . . . . . . . . . . . . . . . 2-5

Establishing GPIB Control . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Front Panel Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Measurement and Data Output . . . . . . . . . . . . . . . . . . . . . . . 2-6

Data Transfer Programming . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

360 GPIB PM 2-1

"SOURCE CONTROL

SYSTEM BUS"

CONNECTOR**

EXT FM
∅ LOCK
OUTPUT*

360 VECTOR NETWORK ANALYZER

SIGNAL
BUS

CONTROL
BUS

"360 GPIB"
CONNECTOR

IEEE-488 GPIB

EXTERNAL COMPUTER/CONTROLLER

TESTSET

PHASE
LOCK
INPUT*

361XA/

362XA

SERIES

PORT 1

DUT

SIGNAL SOURCE

(36SSXX (or 66XXB/67XXB) Series)

PORT 2

RF
INPUT

RF
OUTPUT

* Not used if Signal Source is 67XXB Series
(Refer to 360 VNA Operation Manual).
** Dedicated GPIB for 360 System use.

Figure 2-1. Minimum 360 VNA Configuration with GPIB Control

2-2 360 GPIB PM

SECTION II

INTRODUCTION TO GPIB PROG RAMMING

FOR THE 360 VNA

2-1 INTRODUCTION

This section contains a brief introduction to GPIB
programming techniques and describes procedures
to be used when preparing GPIB programs for the
360 VNA. It includes information about equipment
requirements and configuration for GPIB control of
the 360 VNA, 360 GPIB command syntax, and pro­gramming tips. Example programs are pr ovided that
familiarize the user with the most frequently used
360 GPIB commands.

Familiarity with manual (front panel) operation of
the 360 is assumed. (Throughout this section, the
360 VNA is referred to simply as “360”.) A complete
description of front panel operation is contained in
the 360 Vector Network Analyzer System Operation
Manual.

2-2 EQUIPMENT AND CONFIGURATION

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

4. Appropriate software:

•

Microsoft QuickBASIC, version 4.0 (or later);

•

Microsoft “C”, version 5.1 or later; or:

•

HP BASIC, version 5.0 or later (for HP com­puters).

•

Any other programming language that sup­ports the National Instruments PC2 or PC2A
IEEE-488 interface c ar d (Pa scal, Fortr an, etc ).

5. A GPIB cable (preferably 2 meters long).

2-2.2 Configuration

Configure the 360 as shown in Figure 2-1 (facing
page). Apply power to the 360 and allow the system
software to load from disk. Once the software has
finished loading, the 360 is ready to be remotely
controlled via the GPIB. It is important to note that

the 360 will not re spond to GPIB commands unt il the
360 system software has been loaded.

If not previously done, connect a GPIB cable from
the computer/ contr oller to the “360 GPIB” connec tor
on the rear panel of the 360 Network Analyzer.

2-2.1 Required Equipment

The following equipment represents a minimum
GPIB controllable 360 VNA system:

1. A 360 Ve ctor Network Analyzer consisting of:

•

A 360 Network Analyzer unit

•

A 3600A Series Test Set

•

A compatible WILTRON Signal Source
(360SSXX, 66XXB, 67XXB, etc).

2. A computer/controller that supports the
IEEE-488 GPIB standard. The examples in
this section address the following two computer
types:

•

IBM XT, AT, and PS/2 compatibles,

•

Hewlett Packard 9000 and Vectra series

3. An IEEE-488 GPIB interface (built in, or add-in
peripheral card) with appropriate driver soft­ware. The National Instruments PC2 or PC2A
IEEE-488 interface card is assumed for all
IBM compatible computers.

360 GPIB PM 2-3

The 360 Network Analyzer has two GPIB
busses: the “360 GPIB” that connects the
360 Network Analyzer unit to the com­puter/controller and the “SYSTEM
CONTROL” bus (which connects to the
signal source(s) and a system plotter—if
used).

Apply power to the computer /c ontroller and load the
appropriate programming language software
(QuickBASIC, “C”, or HP BASIC). This tutorial con­tains programming examples written in each of
these three languages, as explained in para­graph 2-4.

2-2.3 Default GPIB Operating Parameters

The default GPIB address for the 360 is 06, and the
default data delimitin g terminator is CR/CR-LF. The
default values for these GPIB operating parameters

NOTE

360 GPIB

PROGRAMMING BASICS

II INTRODUCTIO N TO GPIB PRO GRAMM ING

FOR THE 360 VNA

may be changed via the GPIB SETUP MENU (from
the UTILITY MENU); refer to Index A1 of the 360
Vector Network An alyzer System O peration Manu al.

2-3 360 GPIB PROGRAMMING BASICS

In the “remote” mode of op eration, the 360 is control­led using IEEE-488 Pr odu ct Spec ific Comman ds an d
Interface Function Messages. The Product Specific
Commands are a set of pre-defined mnemonics that
are unique to the WILTRON model 360 Vector Net­work Analyzer. (Refer to paragraph 1-2.3 for further
information .) In this manual, they are refer r ed to as
“360 GPIB commands” or simply “commands”.

These commands may be issued one at a time or in
a sequence (i.e., a command string). Commands,
command strings, and IEEE-488 Interface Function
Messages can be included as part of a program run
on an external computer/controller to remotely
stimulate the 360 to perform particular microwave
measurement operations.

2-3.1 360 GPIB Command Set

There are approximately four hundred 360 GPIB
commands. These commands allow the user to pro­gram every front panel and menu function of the

360. These many commands reflec t the ability of the
360 to perform many specialized functions; however,
typical programs written for ATE applications usu­ally use a small subset of these.

terminator code; example:

SRT 2 GHZ (start freq-

uency = 2 GHz).
The commands for all numeric entry, such as freq-

uency, scale, reference position, etc, include a data
entry followed by a terminator code. All commands
that require data must have a valid terminator code
following the data e ntry.

The 360 will accept multiple commands in string
format. Separator characters may be used to im­prove program readability, but are not required.

a. Termi nator Cod es

These terminators are codes which perform the
same function as the termination keys located
on the front panel of the 360. For example: to
enter a start fr equ en cy usin g th e 360 fr ont pan el
keys, type “40"; then press the ”MHz" terminator
key. Likewise, a numeric entry in a GPIB pro­gram must be termin a ted by one of the termina­tor codes listed in Table 3-2.

b. Separator Characters

Separator characters may be used between com­mands and between data or other mnemonics to
improve program readability. Their use is op­tional. The more common permitted separator
characters are: space, comma, and semicolon.

2-3.3 Programming Tips

The list of GPIB commands may seem intimidating
at first glance; however, it can actually be broken
down into a few, easy-to-remember categories that
reflect th e major f unction s and operation s of the 360.
The GPIB Command Function Index located behind
its section tag at the rear of this manual provides
and overview (and index to) these command group
categories. A complete listing and description of all
360 GPIB commands is provided in Sections III, IV,
and V.

2-3.2 Command Syntax

The 360 GPIB commands are nothing more than a
shorthand method for repr esenting instr u ment com­mands. Most 360 GPIB commands are three charac­ter contractions of their titles or descriptions; for
example:

RST (reset). Depending on function, some

commands must be followed by a numeric value and

The 360 is a “channel-based” instrument, which
means that most commands apply only to the cur­rent active channel. Therefore, to set up a desired
state for multiple channels, a

CH1 - CH4 command

should precede the setup. For example:

“D14 CH1 S11 SMI CH2 S12 MPH CH3 S21 MAG
CH4 S22 ISM”

This command string sets up a quad display (D14)
and then sets the S-parameter and graph type de­sired for each Channel:

Channel 1:
Channel 2:
Channel 3:
Channel 4:

S11, Smit h chart;
S12, log magnitude and phase;
S21, log magnitude;
S22, inverted Smith chart).

Other commands are “global” in their extent, mean­ing they apply to all channels. Examples of these
commands: start/stop frequency (
ing (

AVG,AOF), and source power (PWR).

SRT,STP), averag-

2-4 360 GPIB PM

II INTRODUCTION TO GPIB PROGRAM MI NG
FOR THE 360 VNA TYPICAL GPIB PROGRAM STRUCTURE

2-4 TYPICAL GPIB PROGRAM

STRUCTURE

A typical GPIB program may be composed of the
following basic functional program groups:

Preliminary GPIB Control Establishment

•

Calibration

•

Front Panel Setup

•

Measurement

•

Data Transfer

•

QuickBASIC example:

CALL IBFIND (“DEV6", vna%)
CALL IBCLR

Microsoft C example:

int vna;

vna = ibfind(“DEV6");

ibclr(vna);

Each of these topics will be covered in detail in order
to provide the user with the basic tools needed to
develop complete programs.

This tutorial contains programming examples writ­ten in three languages: QuickBASIC, Microsoft C,
and HP BASIC. The language used is stated for each
example.

HP BASIC example:

100 ASSIGN @gpib TO 7
110 ASSIGN @vna TO 706
120 FORMAT OFF
130 REMOTE @gpib
140 ABORT @gpib
150 CLEAR @vna

2-4.1 Establishing GPIB Control

The first step in any GPIB program should be the
initialization of the GPIB inter face an d any at tached
instruments. This step insures that:

1. Communication has been established between
the computer/controller and the instrument(s),
and,

2. The instrument(s) are restored to a “known”
initial state.

The process used to initialize the 360 will differ,
depending on the computer/controller used.
Examples of initialization ro utines wr itten in Quic k­BASIC and “C” for use with the National
Instruments PC2/PC2A card and HP BASIC for the
Hewlett-Packard GPIB interface are shown in Fig­ure 2-2.

NOTE

In order for communication to take place
over the GPIB, the controlling program
must contain correct GPIB addresses for
the 360 and any other controlled instru­ments. Also, the data delimiting termina­tor used must be correct for the GPIB
interface used with the external com­puter/controller; refer to paragraph 2-2.3.

2-4.2 Front Panel Setup

Figure 2-2. Example Initialization Routines

Front panel setup involves the configuration of the
360 for a particular measurement. In the “Setup”
subroutine, the 360 is setup to display all four S-Pa­rameters (
is set to Log Magnitude and Phase (

D14). The graph type for all four chan ne l s

MPH). The S-pa-

rameters are displayed as follows:

Channel 1 (
Channel 2 (
Channel 3 (
Channel 4 (

The start frequency is set to 40.0 MHz (

) and the stop frequency is set to 20.0 GHz (STP

MHZ

20.0 GHZ

CH1): S11 (S11);
CH2): S12 (S12);
CH3): S21 (S21);
CH4): S22 (S22).

SRT 40.0

). Examples of front panel setup routines

are shown in Figure 2-3.

2-4.3 Calib rat io n

Calibration, as it applies to network analysis, is a
technique used to remove most measurement errors
due to imperfections in the measurement system.
The calibration process ch arac ter izes the systematic
measurement errors. The resulting data is stored
and subtracted from subsequent measurement data
to yield the corr ect measuremen t data for th e device­under-test.

360 GPIB PM 2-5

II INTRODUCTIO N TO GPIB PRO GRAMM ING

TYPICAL GPIB PROGRAM STRUCTURE F OR THE 360 VNA

As performed using the 360 front pan el con tr ols, the
calibration process requires the user to define the
characteristics of the test set test ports, perform the
calibration steps, and then verify the quality of the
calibration. (Refer to Paragraph 4-9 — Measure­ment Calibration — in the 360 Vector Network Ana­lyzer System Operation Manual.)

As shown in the example programs contained in
Section IV of this manual, it is possible to use the
external computer to guide the system operator
through the calibration process using a suitably
written program. The various 360 GPIB commands
that are used to perform the calibration process are
described in the first portion of Section IV. Listings
of example HP BASIC and “C” pr ogram se gments fo r
360 calibration are presented in Section IV, para­graphs 4-2.4 through 4-2.6.

2-4.4 Measurement and Data Output

The commands that control the measurement func­tions of the 360VNA are listed and described in par a­graph 3-4 — Measurement Control Commands.
These commands mimic the measurement opera­tions that are performed using the 360 front panel
keys and menus.

An example of a main program and associated pro­gram functions written in “C” that initialize the 360
and perform c alibration, measurement an d data out­put functions is listed and described in Application
Note AN360-8. A similar example of a main prog ram
and associated subprograms wri tten in HP BASIC is
presented in Application Note AN360-9. These
application notes are included at the rear of this
manual behind the tab labeled “Supplements”.

2-4.5 Data Transfer Programming

The commands that control the transfer of data
to/from the 360 are listed and described in para­graph 5-3 — Data Transfer Commands. The func­tions performed by many of these commands are
unique—most do not have direct counterparts when
operating from the front panel keys and menus.

Figures 2-4 through 2-7 contain listings of an
example program written in “C”. This example is a
complete program that automates data transfer
to/from the 360. The fou r parts of the prog ram shown
in the figures are described in paragraphs b
through e below.

a. Programming Considerations

When writing a program for data transfer
to/from the 360, the following items should be
considered:

•

Data Transfer Sequence — Data may be
transferred from the 360 to the external com-
puter in any order. However, the 360 should
be put in HOL D to prevent th e data fr om bein g
overwritten.

Data should be transferred from the exter­nal computer to the 360 in the following or­der:

Front Panel Setup
Measurement Frequencies
Calibration Coefficients
Measurement Data.

•

Front Panel Setup and Measurement
Frequency Data — Front panel setup data,

including frequency information, is contained
in the data transfers performed by the OFP
and IFP commands. However, when Discrete
Fill is used to enter frequency data, or when
access to individual frequency values is im­portant, the OF V an d IF V comman ds mu st be
used.

•

Data Transfer Formats — Use of the FMA
and FMB commands is the preferred method
of data transfer for Binary floatin g point data.
ASCII data transfer is significantly slower
than for binary floating point data. Also, AS­CII data must be converted to a numeric for­mat using a suitable “C” program to be useful
for most applications.

b. Example Program: Variable Declaration

The program segment shown in Figure 2-4 con­tains the variable declarations for the example
program. These variable dec larations define and

2-6 360 GPIB PM

II INTRODUCTION TO GPIB PROGRAM MI NG
FOR THE 360 VNA TYPICAL GPIB PROGRAM STRUCTURE

initialize the variables common to the main pro­gram and program functions.

c. Example Main Program

The main pro gram show n in Figur e 2-5 perfor ms
the following operations:

1. T he 360 and GPIB are initialized to a known
state by the first two program functions so
that the program starts under identical
conditions each time it is run:

•

GPIB function

ibfind() enables the GPIB

to control the 360 (this assumes that the
360 address is set t o 6.)

•

GPIB function

ibclr() instructs the 360 to

reset to the default state. It is used be­fore 360 parameters are established by
the program.

2. The program function

xfr_from_360() is called

to transfer data from the 360.

3. The program function

xfr_to_360() is called to

transfer data to the 360.

4. T he last program function of the main pro­gram,

ibloc(), instructs the external com-

puter to return the 360 to local operation
and end program execution.

d. Data Transfer from the 360 VNA to the

External Computer

The program function

xfr_from_360() shown in

Figure 2-6 performs the following operations:

1. T he GPIB function
to return to local operation (

ibwrt() instructs the 360

RTL).

2. T he operator is instructed to perform a Re­flection Only calibration, set up the front
panel as desired and install the device to
be measured. They are then instructed to
press any key on the external computer
keyboard to output data from the 360.

3. The next
to the 360 to trigger a sweep (
full sweep(

ibwrt() function sends instructions

TRS), wait a

WFS) and hold (HLD).

QuickBASIC example:

SUB Setup

CALL IBWRT (vna%, “D14 CH1 S11 MPH CH2 S12 MPH”)
CALL IBWRT (vna%, “CH3 S21 MPH CH4 S22 MPH”)
CALL IBWRT (vna%, “SRT 40.O MHZ STP 20.0 GHZ”)
SUB END

Microsoft C example:

Setup (vna)
int vna;
{
ibwrt (vna, “D14 CH1 S11 MPH CH2 S12 MPH”, 27);
ibwrt (vna, “CH3 S21 MPH CH4 S22 MPH”, 23);
ibwrt (vna, “SRT 40.0 MHZ STP 20.0 GHZ”, 25);
}

HP BASIC example:

500 SUB Setup(@vna)
510 OUTPUT @vna;"D14 CH1 S11 MPH CH2 S12 MPH"
520 OUTPUT @vna;"CH3 S21 MPH CH4 S22 MPH"
530 OUTPUT @vna;"SRT 40.0 MHZ STP 20.0 GHZ"

Figure 2-3. Example Front Panel Setup Routines

360 GPIB PM 2-7

II INTRODUCTIO N TO GPIB PRO GRAMM ING

EXAMPLE DATA TRANSF ER PRO GRAM FOR THE 360 VNA

/*************************************************************/
/* Program to Transfer Data over the GPIB */
/* to/from a Wiltron 360 Vector Network Analyzer */
/* using an IBM AT Computer with National Instruments GPIB */
/* Written in Microsoft C */
/*************************************************************/
#include <stdio.h>
/*—————————————————————————————
Variable Declaration
Define and Initialize variables common to all functions.
——————————————————————————————-*/
int ans, vna, count, points;
char freq[12800], setup[5000];
struct header
{
char preamble [2];
int size;
}
cal_headr, data_headr;
struct cal
{
double real;
double imag;
}
cal1[512], cal2[512], cal3[512];
struct data
{ float real;
float imag;
}
data[512];

Figure 2-4. Variable Declaration for Example Data Transfer Program (Microsoft “C”)

/*—————————————————————————————
Main Program
Initialize GPIB and put 360 under GPIB control,
call program functions to transfer data,
and return 360 to local operation.
—————————————————————————————*/
main()
{
vna = ibfind(“DEV6"); /*enables GPIB to control 360*/
ibclr(vna); /*resets 360 to default parameters*/
xfr_from_360(vna); /*calls data output function*/
xfr_to_360(vna); /*calls data input function*/
ibloc(vna); /*returns 360 to_local control*/
} /*ends program*/

Figure 2-5. Main Program for Example Data Transfer Program (Microsoft “C”)

2-8 360 GPIB PM

II INTRODUCTION TO GPIB PROGRAM MI NG
FOR THE 360 VNA EXAMPLE DATA TRANSFER PROGRAM

4. T he 360 is then instructed to output the
data types listed below to the external com­puter. The external computer reads the
data sent from the 360 using multiple

ibrd() functions. The data types transferred

are:

•

Front panel setup data in binary string
format (

•

Measurement frequency values (
ASCII format (

OFP),

OFV) in

FMA),

/*—————————————————————————————
Data Output Function
Setup, calibrate and measure a_device,
transfer data from 360 to controller,
and return 360 to local operation.
—————————————————————————————*/
xfr_from_360(vna)
{
ibwrt(vna,"RTL",3);
printf(“\n\t\t* INSTRUCTIONS *”);
printf(“\n\t\t* Perform a Reflection Only calibration, *”);
printf(“\n\t\t* set up front panel as desired, *”);
printf(“\n\t\t* and connect device to be measured._ *\n”);
printf(“\n\t\t* PRESS ANY KEY TO OUTPUT DATA FROM 360 *\n”);
ans = getch();
ibwrt(vna,"TRS WFS HLD",11);

•

Calibration coefficients (

OC1, OC2, and

OC3) in binary floating point - double

precision (
byte first (

•

Corrected measurement data (

FMB) with the least significant

LSB),

OCD) from

the active channel in binary floating
point - single precision (
least significant byte first (

FMC) with the

LSB).

5. When the data transfer is completed, the
360 is again returned to local operation.

printf(“\n\t\tTransferring front panel setup to controller...”);
ibwrt(vna,"OFP",3);
ibrd(vna,setup,sizeof(setup));

printf(“\n\t\tTransferring frequencies to controller...”);
ibwrt(vna,"FMA OFV",7);
ibrd(vna,freq,sizeof(freq));

printf(“\n\t\tTransferring cal coefficients to controller...”);
ibwrt(vna,"FMB LSB OC1 OC2 OC3",19);
ibrd(vna,&cal_headr,4);
ibrd(vna,&cal1[0],cal_headr.size);
ibrd(vna,&cal_headr,4);
ibrd(vna,&cal2[0],cal_headr.size);
ibrd(vna,&cal_headr,4);
ibrd(vna,&cal3[0],cal_headr.size);

printf(“\n\t\tTransferring measurement data to controller...”);
ibwrt(vna,"FMC LSB OCD",11);
ibrd(vna,&data_headr,4);
ibrd(vna,&data[0],data_headr.size);

printf(“\n\n\t\t —- 360 returned to local operation.—-\n”);
ibwrt(vna,"RTL",3);

Figure 2-6. Output Data Transfer Program Function for Example Data Transfer Program (Microsoft “C”)

360 GPIB PM 2-9

II INTRODUCTIO N TO GPIB PRO GRAMM ING

EXAMPLE DATA TRANSF ER PRO GRAM FOR THE 360 VNA

e. Data Transfer from the External Computer

to the 360 VNA

The program function

xfr_to_360() shown in Fig-

ure 2-7 performs the following sequence of op­erations:

1. T he operator is instructed to press any key
on the external computer keyboard to out­put data to the 360.

2. The program function

prn_data() (shown in

Figure 2-7, sheet 2) then displays the meas-

/*————————————————————————————­ Data Input Function
Reset 360 to default parameters,
transfer data from controller to 360,
and turn on calibration.
————————————————————————————-*/
xfr_to_360(vna)
{
printf(“\n\t\t* PRESS ANY KEY *”);
printf(“\n\t\t* TO DISPLAY CAL DATA AND OUTPUT DATA TO 360*\n”);
ans = getch();
ibwrt(vna,"RST",3);

urement frequency data and calibration co­efficients on the external computer monitor
(Figure 2-8).

3. The 360 is then instructed to input the data
types listed below from the external com­puter. The external computer sends the
data to the 360 using multiple

ibwrt() func-

tions. The data types transferred are:

•

Front panel setup (

IFP) in bina ry s tring

format,

prn_data();

points=data_headr.size/8;

printf(“\n\t\tTransferring front panel setup to 360...”);
ibwrt(vna,"IFP",3);
ibwrt(vna,setup,sizeof(setup));

printf(“\n\t\tTransferring frequencies to 360...”);
ibwrt(vna,"FMA IFV",7);
ibwrt(vna,freq,points*25);

printf(“\n\t\tTransferring cal coefficients to 360...”);
ibwrt(vna,"ARF FMB LSB IC1 IC2 IC3",24);
ibwrt(vna,&cal_headr,4);
ibwrt(vna,&cal1[0],cal_headr.size);
ibwrt(vna,&cal_headr,4);
ibwrt(vna,&cal2[0],cal_headr.size);
ibwrt(vna,&cal_headr,4);
ibwrt(vna,&cal3[0],cal_headr.size);
ibwrt(vna,"CON",3);

printf(“\n\t\tTransferring measurement data to 360...”);
ibwrt(vna,"FMC LSB ICD",11);
ibwrt(vna,&data_headr,4);
ibwrt(vna,&data[0],data_headr.size);

printf(“\n\n\t\t —- 360 data transfer completed —-”);
}

Figure 2-7. Input Data Transfer Program Function for Example Data Transfer Program (1 of 2)

2-10 360 GPIB PM

II INTRODUCTION TO GPIB PROGRAM MI NG
FOR THE 360 VNA EXAMPLE DATA TRANSFER PROGRAM

•

Frequency values (
(

FMA),

•

Calibration coefficients (IC1, IC2 and

) in binary floating point - double pre-

IC3

cision (
byte first (

•

Corrected measurement data (

FMB) with the least significant

LSB),

IFV) in ASCII format

the active channel in binary floating

prn_data()
{
points=cal_headr.size/16;

printf(“\n\n\n\t\t —- CALIBRATION COEFFICIENTS —-”);
printf(“\nFREQUENCY CAL1 CAL2");
printf(“ CAL3\n”);
printf(“ (GHz) (Real) (Imag) (Real) (Imag)”);
printf(“ (Real) (Imag)\n”);

for (count=0;count<points;count=count + 1)
printf(“ %c.%c%c %9.4f %9.4f %9.4f %9.4f %9.4f %9.4f\n”,
freq[count*25+3],
freq[count*25+5],freq[count*25+6],
cal1[count].real, cal1[count].imag,
cal2[count].real, cal2[count].imag,
cal3[count].real, cal3[count].imag);
}

ICD) from

point - single precision (
least significant byte first (

FMC) with the

LSB).

4. T he 360 is instructed to simulate a Reflec­tion Only calibration (
the calibration coefficients (

IC3). The calibration is then applied (CON),

AFR) before it is sent

IC1, IC2 and

and the corrected data is displayed on the
360 monitor.

Figure 2-7. Input Data Transfer Program Function for Example Data Transfer Program (2 of 2)

—- CALIBRATION COEFFIClENTS —-

FREQUENCY CAL1 CAL2 CAL3

(GHz) (Real) (Imag) (Real) (I mag) (Real) (Imag)

1.00 -0.0092 0.0010 0.0332 -0.0096 -0.1188 -0.2103

1.10 -0.0062 -0.0079 -0.0334 -0.0221 -0.2540 -0.0176

1.20 0.0052 -0.0086 0.0280 0.0505 -0.1614 0.2134

1.30 0.0126 0.0019 -0.0032 -0.0661 0.8899 0.2584

1.40 0.0058 0.0132 -0.0149 0.0290 0.2714 0.0803

1.50 -0.0100 0.0113 0.0253 0.0245 0.2306 -0.1893

1.60 -0.0180 -0.0050 0.0019 -0.0472 -0.0326 -0.3096

1.70 -0.0068 -0.0201 -0.0318 0.0208 -0.2822 -0.1468

1.80 0.0143 -0.0170 0.0097 0.0396 -0.2833 0.1616

1.90 0.0240 0.0030 0.0482 -0-0528 -0.0120 0.3308

2.00 0.0098 0.0205 -0.0782 0.0045 0.2655 0.1846

Figure 2-8. Frequency and Calibration Data Displayed on External Computer Monitor by xfr_to_360()

360 GPIB PM 2-11/2-12

SECTION III

COMMANDS FOR BASIC

FRONT PANEL FUNCTIONS

Table of Contents

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

3-2 CHANNEL CONTROL COMMANDS . . . . . . . . . . . . . . . . . . . . 3-3

3-3 DATA ENTRY TERMINATOR CODES . . . . . . . . . . . . . . . . . . . 3-3

3-4 MEASUREMENT CONTROL COMMANDS . . . . . . . . . . . . . . . . 3-4

3-5 DISPLAY CONTROL COMMANDS . . . . . . . . . . . . . . . . . . . . . 3-6

3-6 ENHANCEMENT COMMANDS . . . . . . . . . . . . . . . . . . . . . . . 3-8

3-7 REFERENCE DELAY COMMANDS . . . . . . . . . . . . . . . . . . . . . 3-9

3-8 TRACE MEMORY COMM ANDS . . . . . . . . . . . . . . . . . . . . . . 3-10

3-9 MARKER COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

3-10 LIMITS COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3-1 1 HARD COPY COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . 3-13

3-12 SYSTEM ST ATE COMMANDS . . . . . . . . . . . . . . . . . . . . . . 3-15

3-13 TEST SET MULTIPL EXER CONTROL COMMANDS . . . . . . . . . . 3-17

3-14 VIDEO SWITCH CONTROL COMMANDS . . . . . . . . . . . . . . . . 3-17

3-15 PULSE SYSTEM COMMAND . . . . . . . . . . . . . . . . . . . . . . . 3-18

3-16 NOISE FIGURE SYSTEM COMMANDS . . . . . . . . . . . . . . . . . 3-18

3-17 MILLIMETER-WAVE TEST SET COMMANDS . . . . . . . . . . . . . 3-18

360 GPIB PM 3-1/3-2

SECTION III

COMMANDS FOR BASIC

FRONT PANEL FUNCTIONS

3-1 INTRODUCTION

This section describes the GPIB Product Specific
Commands that control the basic test and measure­ment functions associated with the 360 VNA front
panel c ontrols an d menus. In th is section , the se m es­sages are refered to as “360 GPIB commands” or
simply “commands”. The command information is
grouped by control function; example: Data Entry
Commands, Hard Copy Commands, etc., (see Table
of Contents, page 3-1).

To find command information not in this section,
refer to the GPIB Command Function Index for a
listing of all 360 GPIB commands, grouped by func­tion. Refer also to the 360 Quick Reference Guide,
which lists all commands alphabetically and
includes a brief description of the function of each
command. (See section tabs at rear of manual.)

3-2 CHANNEL CONTROL COMMANDS

The commands listed in T able 3-1 set up the curr ent
display mode and active channel for the 360 VNA.
Commands D13, D14, D24 and DSP select which
channels are to be displayed. Commands CH1–CH4
select the active channel. The active channel is that
channel to which any channel-based changes are
applied.

Table 3-1. Channel Control Commands

360 GP IB

Command

Description

3-3 DATA ENTRY TERMINATOR CODES

The codes listed in table 3-2 are used as terminator
statements in conjunction with commands that
require numeric values. (Almost all commands that
require numeric values also require the use of an
appropriate terminator.) The appropriate termina­tors for commands requiring them are listed along
with the description of the command in the tables
throughout this section and in Sections IV and V.

Table 3-2. Data Entry Terminator Codes

Terminator

Code

CMT Select centimeter as terminator
DBL Select dB log as terminator
DBM Select dBm as terminator
DEG Select degrees as terminator
GHZ Select gigahertz as terminator
IMU Select imaginary units as terminator
KHZ Select kilohertz as terminator
MHZ Select megahertz as terminator
MMT Select millimeter as terminator
MTR Select meter as terminator

Description

DSP Select single channel of active display
D13 Select dual channel display, channels 1 & 3
D14 Select quad display, all four channels
D24 Select dual channel display, chans 2 & 4
CH1 Select channel 1 as active channel
CH2 Select channel 2 as active channel
CH3 Select channel 3 as active channel
CH4 Select channel 4 as active channel

NSC Select nanoseconds as terminator
PSC Select picoseconds as terminator
REU Select real units as terminator
USC Select microseconds as terminator
VLT Select volts as terminator
XM3 Select unitless terminator, x 10E-3
XX1 Select unitless terminator, x 1
XX3 Select unitless terminator, x 10E+3

360 GPIB PM 3-3

MEASUREMENT CONT ROL COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

3-4 MEASUREMENT CONTROL

COMMANDS

The commands listed in Table 3-3 control the pa­rameter being measured on the active channel (S11,
S21, S22, and S12) and the basic measurement
setup. All commands except S11, S21, S22, and S12
are global; that is, they apply to the entire instru­ment.

The SA1, SA2, and TA2 commands can only be used
with the Models 3620, 3621 and 3622 Test Sets (i.e.,
test sets with attenuators). Note th a t the two sou rce
attenuators have ranges of 0 to 70 dB while the test
attenuator has a range of 0 to 40 dB.

Table 3-3. Measurement Control Commands (1 of 2)

360 GP IB

Command

BH0 Set bias off while in hold N/A N/A
BH1 Set bias on while in hold N/A N/A
CTN Continue sweeping from current point N/A N/A
CWF (value) CW turned on and CW frequency set to

value

Description Values Terminators

The HLD command holds the sweep at the current
point; the CTN command continues sweeping from
the current poin t. T he TRS command eithe r restart s
the sweep (continuous sweep mode) or triggers a
single sweep (in hold mode). The SWP command
puts the 360 into continuous swept mode.

The WFS command causes the 360 to wait a full
sweep so that any data on the display is valid. This
is useful for scaling the display. It is requi re d wh en
outputting data from the 360, so as to e nsure that
the data being output is valid (see Section V, para­graph 5-3.1, Data Transfer Program Example and
Prog ram N ot es).

Start sweep frequency to

stop sweep frequency

GHZ, MHZ, KHZ

DA1 Select a1=Ra as denominator for parameter

being defined

DA2 Select a2=Rb as denominator for parameter

being defined

DB1 Select b1=Ta as denominator for parameter

being defined

DB2 Select b2=Tb as denominator for parameter

being defined

DE1 Select unity as denomitor for parameter

being

defined
FHI Set data points to maximum N/A N/A
FLO Set data points to minimum N/A N/A
FME Set data points to normal N/A N/A
HLD Hold instrument at current point N/A N/A
LA1 Select a1=Ra as phase lock for parameter

being defined
LA2 Select a2=Rb as phase lock for parameter

being defined
NA1 Select a1=Ra as numerator for parameter

being defined

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

3-4 360 GPIB PM

III BASIC FRONT PANEL GPIB COMMANDS MEASUREMENT CONTROL COMMANDS

Table 3-3. Measurement Control Commands (2 of 2)

360 GP IB

Command

NA2 Select a2=Rb as numerator for parameter

Description Values Terminators

N/A N/A

being defined

NB1 Select b1=Ta as numerator for parameter

N/A N/A

being defined

NB2 Select b2=Tb as numerator for parameter

N/A N/A

being defined

NU1 Select unity as numerator for parameter

N/A N/A

being defined

PW2 (value) Set source 2 power level in dBm Depends on power range

DBM, XX1, XX3, XM3

of source

PWR (value) Set source 1 power level in dBm Depends on power range

DBM, XX1, XX3, XM3

of source
RH0 Set RF off while in hold N/A N/A
RH1 Set RF on while in hold N/A N/A
S11 Measure S
S12 Measure S
S21 Measure S

on active channel N/A N/A

11

on active channel N/A N/A

12

on active channel N/A N/A

21

S22 Measure S

on active channel N/A N/A

22

SA1 (value) Set source attenuator, port 1 0 dB to 70 dB DBL, DBM, XX1, XX3,

XM3

SA2 (value) Set source attenuator, port 2 0 dB to 70 dB DBL, DBM, XX1, XX3,

XM3

SRT (value) Set start frequency Start sweep frequency to

GHZ, MHZ, KHZ

stop sweep frequency

STP (value) Set stop frequency Start sweep frequency to

GHZ, MHZ, KHZ

stop sweep frequency
SWP Frequency sweep mode N/A N/A
TA1 (value) Test set port 1 test attenuator 0 to 100

(Depends on test set)
TA2 (value) Set test attenuator, port 2 0 to 100

(Depends on test set)

DBL, DBM,

XX1, XX3, XM3

DBL, DBM,

XX1, XX3, XM3
TRS Trigger/restart sweep N/A N/A
US1-US4 Measure user parameter 1-4 on active channel N/A N/A
USL (string) Enter user parameter label string 5 characters max N/A
WFS Wait full sweep until all display data is valid N/A N/A

360 GPIB PM 3-5

DISPLAY CONTRO L COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

3-5 DISPLAY CONTROL COMMANDS

The commands listed in Table 3-4 set up the graph
type on the active channel. Most of these commands
are straightfor w ard with the exc eption of SME, ISE,
SMC and ISC. Both the SME and ISE commands
require values and terminators to be included with
the command (see Table 3-4). The allowable values
for these commands are 10, 20, and 30.

Example: “SME 20 DBL” This code selects a 20 dB
expanded Smith chart on the active channel.

Commands SMC and ISC also require values and
only allow the value 3.

Example: “SMC 3 DBL” This code selects a 3 dB
compressed Smith chart on the active channel. Ad­ditional considerations for commands SCL and REF
are as follows:

a. SCL Command

The SCL command sets the scaling-per-division
of the graph on the active channel. Notice that
for graph types with two types of information,
the unitless terminators alway s apply to the first
type of information. T he first type of infor m ation
is always displayed on the top graph

Example: “MPH SCL 10 XX1" This code will
select a log magnitude and phase display on the
active channel and set the magnitude scaling to

10 dB/div. The only way to scale the degrees part
of the graph is by explicit use of the DEG
terminator.

Example: “MPH SCL 45 DEG” This code se-
lects a log magnitude and phase display on the
active channel and sets the phase scaling to 45
degrees/div.

NOTE

Smith charts and inverted Smith
charts can not be scaled using the
SCL command—the different charts
are selected using the SME, ISE,
SMC, and ISC commands.

b. REF Command

The REF command selects which graticule line
will be con sidered the “refer enc e.” Notice th at for
graphs with one type of information—such as
MAG or PHA—the allowable reference line val­ues are 0 to 8, while for graphs with two types
of information the reference line value can only
be 0 to 4. As described for the SC L comman d, for
graphs having two types of information present,
the unitless terminators apply to the first type
of information. There is no referen ce line defin ed
for Smith charts, inverted Smith charts, linear
polar, or log polar displays.

Table 3-4. Display Control Commands (1 of 2)

360 GPIB

Command

APR (value) Set group delay aperture for display on

active channel
ASC Autoscale display on active channel N/A N/A
ASP (value) Set polar stop sweep position angle 0 to 360 (–360 to +360) DEG
AST (value) Set polar start sweep position angle 0 to 360 (–360 to +360) DEG
DLA Select group delay display for active

channel
IMG Select imaginary display for active

channel
ISC (value) Select inverted compressed Smith chart

for active channel
ISE (value) Select inverted expanded Smith chart

for active channel
ISM Select normal inverted Smith chart for

active channel

Descri pt ion Values Term in ato rs

0 to 20 XX1, XX3, XM3

N/A N/A

N/A N/A

3 DBL, XX1

10, 20, 30 DBL, XX1

N/A N/A

3-6 360 GPIB PM

III BASIC FRONT PANEL GPIB COMM ANDS DISPLAY CONTROL COMMANDS

Table 3-4. Display Control Commands (2 of 2)

360 GPIB

Command

LIN Select linear magnitude display for

Descri pt ion Values Term in ato rs

N/A N/A

active channel

LPH Select linear magnitude and phase

N/A N/A

display for active channel

MAG Select log magnitude display for active

N/A N/A

channel

MPH Select log magnitude and phase display

N/A N/A

for active channel

OFF (value) Set offset for display on active channel Mag offset:

–999.99 – 999.99

Depends on graph type

Phase offset: –360 to e360

Polar offset: 0

Lin polar offset: 5E

PCP Select measurement phase polar chart

– 999.99

-9

– 1000. 0

N/A N/A

mode
PCS Select sweep position polar chart mode N/A N/A
PHA Select phase display for active channel N/A N/A
PHO (value) Set phase offset for display on active

0 to 360 (–360 to +360) Depends on graph type

channel
PLG Select log polar display for active

N/A N/A

channel
PLR Select linear polar display for active

N/A N/A

channel
REF (value) Set reference line for display on active

channel

If single graph: 1– 8

If two graphs: 1 –4

Depends on graph type

REL Select real display for active channel N/A N/A
RIM Select real and imaginary display for

N/A N/A

active channel
SCL (value) Set resolution for display on active

channel

Mag resolution: 0.001 – 50

Phase resolution: 0.01 – 90

Polar resolution: 1E

-9

– 999.99

Depends on graph type

Lin polar resolution: 200 max

SMC (value) Select compressed Smith chart for

3 DBL, XX1

active channel
SME (value) Select expanded Smith chart for active

10, 20, 30 DBL, XX1

channel
SMI Select normal Smith chart for active

N/A N/A

channel
SWR Select SWR display for active channel N/A N/A

360 GPIB PM 3-7

ENHANCEMENT COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

3-6 ENHANCE MENT COM MAND S

include IF bandwidth, averaging, and smoothing.

Note that for the averaging function the maximum
The commands listed in Table 3-5 control the data
enhancement functions of the 360 VNA. These

Table 3-5. Enchancement Commands

360 GPIB

Command

AOF Turn off averaging N/A N/A
AVG (value) Turn on averaging and set to value 1 to 4095 XX1, XX3, XM3
IFM Select minimum I.F. bandwidth N/A N/A
IFN Select normal I.F. bandwidth N/A N/A
IFR Select reduced I.F. bandwidth N/A N/A
SOF Turn off smoothing N/A N/A
SON (value) Turn on smoothing and set to value (%) 0 to 20 XX1, XX3, XM3

Description Values Terminators

averaging number is 4095. For the smoothing func-

tion, the maximum smoothing number is 20 (%).

3-8 360 GPIB PM

III BASIC FRONT PANEL GPIB COMMANDS REFERENCE DELAY COMMANDS

3-7 REFERENCE DELAY COMMANDS

channel reference delay while commands DIA, DIT,
DIP, DIM, and DIE change the system dielectric

The commands listed in Table 3-6 are used to set up
both the r efer ence delay ap plied to a ch anne l an d the
relative dielectric constant of the system. Note that

constant—which is a global change. The command
RDA should only be used if at least one valid sweep
has been previously completed.

commands RDD, RDT, and RDA change the active

Table 3-6. Reference Delay Commands

360 GPIB

Command

DIA Select air as active dielectric N/A N/A
DIE (value) Set active dielectric to value 1 to 999.999 XX1, XX3, XM3
DIM Select microporous teflon as active dielectric

(1.69)
DIP Select polyethylene as active dielectric (2.26) N/A N/A
DIT Select teflon as active dielectric (2.1) N/A N/A
RDA Set automatic reference delay calculation N/A N/A
RDD (value) Set reference delay in distance for active

channel
RDT (value) Set reference delay in time for active channel

Description Values Terminators

N/A N/A

–999.999 to 999.999 MMT, CMT, MTR

–999.999 to 999.999 µs

PSC, NSC, USC

360 GPIB PM 3-9

TRACE MEMORY COM MANDS III BASIC FRONT PANEL GPIB COMMANDS

3-8 TRACE MEMORY COMMANDS

The commands listed in Table 3-7 control the trace
memory function on the active chan nel and the trace
math that can be applied to it. Before using the

Store data to memory (STD).

•

Select complex division as the trace math (DIV).

•

Display the data normalized to memor y u sing th is

•

trace math (DNM).

commands MEM, DTM or DNM to view a display
that involves trac e memory, or to store trace me mory
to disk, the data from th e selected c hannel mu st firs t
be stored to memory using the STD command.

Example: “WFS STD DIV DNM”
This example code causes the 360 to:

Wait a full sweep until data is valid (WFS).

•

Table 3-7. Tra ce Me mory Comm and s

360 GPIB

Command

ADD Select addition as trace math for active channel
DAT Display measurement data on active channel
DIV Select division as trace math for active channel
DNM Display data normalized to trace memory on active channel
DTM Display measurement data and trace memory on active channel
MEM Display trace memory on active channel

The SDK and RCK commands that are
used to store an d retr ieve the active chan ­nel trace memory to an d f rom th e di sk ar e
described in Section V, paragraph 5-5,
Disk Functions Commands.

Description

NOTE

MIN Select subtraction as trace math for active channel
MUL Select multiplication as trace math for active channel
STD Sto re trace to m e mo ry

3-10 360 GPIB PM

III BASIC FRONT PANEL GPIB COMMANDS MARKER COMMANDS

3-9 MARKER COMMANDS

The commands listed in Table 3-8 control the locat­ion and display of the markers and the functions
related to the markers. The MK1–MK6 commands
are used to set a marke r to a desired fr equenc y, time,
or distance. The terminator mnemonics used must
match the active channel domain (frequency point,
time, or distance)—Otherwise, an action-not-possi­ble error will result.

Example: “MK1 1.0000 NSC” trying to use this
code for a frequency domain channel will generate
an action-not-possible error.

Markers can be individually turned off using the
MO1–MO6 comman ds. These comman ds remove the
specified marker and the readout from the screen
display.

All markers can be disabled using the MOF com-
mand. This command removes the marker from the
display, but the marker readout remains.

A marker is turned on w he ne ve r any of th e following
conditions occur:

When the marker is set to a value, for example:

•

“MK2 4.5632 GHZ”.

When the marker is selected for readout, for

•

example:

“MR2"

When the marker is selected as the delta refer-

•

ence marker, for example : “DR2"

The MMN and MMX commands move the active
marker to the minimum and maximum trace values
on the active channel, respectively. There must be
an active marke r selected fo r th ese comman d to ex e­cute.The M1S–M6S, M1E–M6E and M1C–M6C
command are used to define a marker sweep using
the specified mark er for either the start, stop, or CW
frequenc y.

Example: “WFS MR1 MMX M1S”

This code sequence causes the 360 to:

Wait for a full sweep of data to be present (WFS).

•

Turn on marker 1 and select it for readout (MR1).

•

Move marker 1 to the maximu m value of the trace

•

on the active channel (MMX).

Set the start frequency equal to the marker

•

frequency (M1S).

Table 3-8. Marker Commands

360 GPIB

Command

DR1-DR6 Select marker 1 - 6 as delta reference marker N/A
DRF Tu rn delta reference mode on N/A
DRO Turn delta reference mode off N/A
M1C-M6C Set marker 1-6 sweep CW frequency N/A
M1E-M6E Set marker 1-6 sweep/zoom end freq, time or distance N/A
M1S-M6S Set marker 1-6 sweep/zoom start freq, time or distance N/A
MK1 (value) –

MK6 (value)
MMN Set active marker to minimum trace value N/A
MMX Set active marker to maximum trace value N/A
MO1-MO6 Turn off marker 1-6 N/A
MOF Marker display off N/A
MON Marker display on N/A
MR1-MR6 Read-out frequency at marker 1-6 (through GPIB) N/A

Turn on marker 1-6 and set to value Limited t o current sw e ep /zo om

Description Values

range

360 GPIB PM 3-11

LIMITS COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

3-10 LIMITS COMMANDS

The Limits Commands listed in Table 3-9:

Set up the upper and lower limit values for the

•

active channel.
Set the limit delta for the limit frequency readout

•

function. The range of values and allowable ter­minator mnemonics are dependent on the graph
type of the active channe l, mu c h like th e SCL and
REF commands described in paragraph 3-5.

For graph types that have two types of information,
the unitless terminators always apply to the first
type of information. The first type of information is
always displayed on the top graph. The second type
of limit line value is accessed by explicit use of the
appropriate data terminator mnemonic.

Examples:

1. “LUP 20 XX1" for a log magnitude and phase
display: sets the upper limit on the magnitude
display to 20 dB.

Table 3-9. Limits Commands

2. “LUP 45 DEG” must be used to set the upper

limit on the phase graph.

NOTE

The LFR, LFP, and LFD commands that
deal with limit frequency readouts, are
only available on the following graph
types: log magnitude (MAG), log magni­tude and phase (MPH), phase (PHA), lin­ear magnitude (LIN), linear magnitude
and phase (LPH), standing wave ratio
(SWR), an d group delay (DLA). The ac tive
channel must be a frequency domain
channel.

The LFP command can be used to select
phase limit frequency readouts on log
magnitude and phase and linear magni­tude and phase graph types. If the LFR
command is used for eith er of these g rap h
types, the magnitude limit frequency
readout menu for the channel is
displayed.

360 GPIB

Command

LFD (value) Set limit frequency read-out delta value Depends on graph type Depends on graph type
LFP Select limit frequency read-out for phase

displays

LFR Select limit frequency read-out for active

channel
LLO (value) Turn on lower limit and set to value Depends on graph type Depends on graph type
LOF Turn limits display off N/A N/A
LON Turn limits display on N/A N/A
LUP (value) Turn on upper limit and set to value Depends on graph type Depends on graph type

Description Values Terminators

N/A N/A

N/A N/A

3-12 360 GPIB PM

III BASIC FRONT PANEL GPIB COMMANDS HARD COPY COMMANDS

3-11 HARD COPY COMMANDS

The commands concerned with hard copy output are
listed in Tables 3-10 and 3-11. These commands are
straightforward with the exception of commands
PT0–PT9. The PT0–PT9 commands are used to:

(1) Specify the density of tabular data points out-

put to the printer when using the PTB and
PMT commands, and

(2) Specify the number of data points included in

the output file used with the TDD command.

The value used with the PT0–PT9 commands speci­fies the number of points that are skipped during
printing. Therefore, PT0 selects the densest printing
mode while PT9 gives the fewest number of data
points. The HD0 command disables headers and
page for matting f or tabular pr intou ts. Th e HD 1 co m­mand enables headers and page formatting.

The hard copy outpu t comman ds cons ist of two cate­gories: setup and action:

Setup commands are those that specify the de­sired size and location of the plot and the pen

numbers for each element of the plot. These
commands are described in Table 3-10.

Action commands actually initiate a plot for the
subset of the display specified by the setup com­mands. These commands are described in Ta­ble 3-11.

The LMS, LID, LDT, and LNM commands require a
string of characters to be sent over the GPIB along
with the command. A string input to the 360 must
have the quote characters (“ ”) surrounding the de­sired char ac te rs f or the s tring an d cannot exceed the
maximum number of characters specified for the
command. An example of embedding quote charac­ters in a string sent to the 360 is shown in Fig­ure 3-1. This example is in HP 85 BASIC:

The TDD and TTB commands enable the user to
store tabular data to the disc and recall it for output
to the printer with the tabular printout points con­trolled by commands PT0–PT9. These commands
are described in Section V, paragraph 5-5, Disk
Function Commands.

Table 3-10. Setup Commands for Hard Copy Output (1 of 2)

360 GPIB

Command

DPN (value) Enter pen number for data 1 to 8 XX1
FFD Form feed to printer/stop print/plot N/A N/A
GPN (value) Enter pen number for graticule 1 to 8 XX1
HD0 Turn off tabular data headers and page

formatting

HD1 Turn on tabular data headers and page

formatting
HPN (value) Enter pen number for header 1 to 8 XX1
LDT (string) Enter label string for operator’s name String of characters up

LID (string) Enter label string for device I.D. String of characters up

LMS (string) Enter label string for model/serial number String of characters up

LNM (string) Enter label string for operator’s name String of characters up

MPN (value) Enter pen number for markers and limits 1 to 8 XX1

Description Values Terminators

N/A N/A

N/A N/A

to 12 characters long

to 12 characters long

to 12 characters long

to 12 characters long

N/A

N/A

N/A

N/A

PBL Select quarter-size plot, bottom left corner N/A N/A
PBR Select quarter-size plot, bottom right corner N/A N/A
PFL Select full-size plot N/A N/A

360 GPIB PM 3-13

HARD COPY COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

Table 3-10. Setup Commands for Hard Copy Output (2 of 2)

360 GPIB

Command

PT0-PT9 Select tabular printout points skipped, 0-9 N/A N/A
PTL Select quarter-size plot, top left corner N/A N/A
PTR Select quarter-size plot, top right corner N/A N/A
SPD (value) Enter pen speed percentage 10 to 100 XX1, XX3, XM3

360 GPIB

Command

PFS Print full screen image N/A N/A
PGR Print graph area screen image N/A N/A
PGT Plot graticule N/A N/A
PLD Plot data area only N/A N/A
PLH Plot header N/A N/A
PLM Plot markers and limits N/A N/A
PLS Plot entire screen N/A N/A
PLT Plot data traces only N/A N/A

Description Values Terminators

Table 3-11. Action Commands for Hard Copy Output

Description Values Terminators

PMK Print t a bular da ta f o r marke rs N/A N /A
PMN Plot menu N/A N/A
PMT Print tabular data for traces and markers N/A N/A
PST Stop print/plot N/A N/A
PTB Print tabular data for traces N/A N/A

10 ! EXAMPLE ON USE OF STRINGS
20 Q$=CHR$(34) ! QUOTE SYMBOL
30 M$="4_TO_8_FILTR" ! MODEL
40 I$="456789" ! I.D.
50 D$="8/25/87" ! DATE
60 O$="GPIB_WHIZ" ! OPERATOR
70 OUTPUT 706 “LMS”Q$&M$&Q$
80 OUTPUT 706 “LID”&Q$&I$&Q$
90 OUTPUT 706 “LDT”&Q$&D$&Q$
100 OUTPUT 706 “LNM”&Q$&O$&Q$
110 END

Figure 3-1. An Example of Hard Copy Code Using Embedded Quotes

3-14 360 GPIB PM

III BASIC FRONT PANEL GPIB COMMANDS SYSTEM STATE COMMANDS

3-12 SYSTEM STATE COMMANDS

Table 3-12 lists the system state commands. These
commands are used to specify CRT display parame­ters, information display format, and other parame-

Table 3-12. System State Commands (1 of 2)

360 GPIB

Command

ACF Accept 360 system configuration N/A
BC0 Set CRT blanking on (screen blanked) Allows for the ultimate in security — a totally blank

BC1 Set CRT blanking off (screen active) Screen blanking is turned off .
BLU Select blue as third color Allows selection of the third color used by the 360 for

CYN Select cyan as third color Allows selection of the third color used by the 360 for

DC1 Display channel 1 and 2 operating

parameters

DC3 Display channel 3 and 4 operating

parameters

Definition Notes

ters that control the operation of the system. The
function of approximately half of these commands is
to display test set connector type information on the
system screen.

screen. In this mode, the 360 is fully operational over
the GPIB but nothing appears on display.

markers, limits, and some menu annotation

markers, limits, and some menu annotation.
Displays channels 1 and 2 operating parameters in the

data area of the screen.
Displays channels 1 and 2 operating parameters in the

data area of the screen.

DCP Display calibration parameters Displays calibration parameters in the data area of the

screen.

DF2 Display 2.4 mm female connector

information

DF3 Display GPC-3.5 female connector infor-

mation

DFK Display K female connector information N/A
DFN Display TYPE N female connector

information

DFP Display front panel instrument state Displays global operating parameters in the dat a area of

the screen.
DFS Display SMA female connector information N/A
DFT Display TNC female connector information N/A
DFV Display V female connector information N/A
DG7 Display GPC-7 male connector information N/A
DGS Display GPIB status information DIsplays the GPIB system parameters in the data area

of the screen.
DM2 Display 2.4 mm male connector information N/A
DM3 Display GPC-3.5 male connector

information.

N/A

N/A

N/A

N/A

DMK Display K male connector information N/A
DMN Display TYPE N male connector information

DMS Display SMA male connector information N/A

N/A

360 GPIB PM 3-15

SYSTEM STATE COM MANDS III BASIC FRONT PANEL GPIB COMM ANDS

Table 3-12. System State Commands (2 of 2)

360 GPIB

Command

DMT Display TNC male connector information N/A
DMV Display V male connector information N/A
DWG Display waveguide parameters N/A
FOF Frequency information blanked Instructs the 360 to blank any frequency information

FON Frequency information displayed Frequency blanking can be turned off using this code.
INT Initialize (format) data-only disk in drive See Paragraph 5-5
RST Reset instrument to default parameters Similiar to pressing the “DEFAULT PROGRAM” key
RTL Return to local (front panel) control Performs the same function as the control panel

TST Perform self test Performs the same self-test function as the SELF TEST

Definition Notes

from the screen and any hard copy output. This code is
useful
for security reasons.

RETURN TO LOCAL key. This code has no effect if the
360 is in local lockout.

menu selection from the TESTS menu. Returns a string
of 20 zeros if self test passes. Returns up to 20 error
numbers if fail. For a listing of error messages that
correspond to the error numbers, refer to the ERROR
AND STATUS MESSAGES information contained in
Section IV of the 360 Vector Network Analyzer
Operation Manual.

3-16 360 GPIB PM

TEST SET MULTIPLEXER

INTERNAL

SIGNAL

360 NETWORK ANALYZER

EXTERNAL

VGA MONITOR

EXTERNAL

COMPUTER

INTERNAL

SCREEN

DISPLAY

CIRCUITS

EXTERNAL
SIGNAL

III BASIC FRONT PANEL GPIB COMMANDS AND VIDEO SWITCH COMM ANDS

3-13 TEST SET MULTIPLEXER CONTROL

COMMANDS

Table 3-13 list the test set multiplexer commands.
These commands control the 360 Test Set Multi­plexer during remote (GPIB) system operation.

Command ACF—Accept 360 System Configura­tion—is normally used in conjunction with these
commands (refer to paragraph 3-12—System State
Commands). Commands SFA and SFB are used to
control an external A/B RF switch (if used).

NOTE

The 360 Test Set Multiplexer is an option
to the 360 VNA. The external A/B RF
switch is customer supplied.

Table 3-13. Test Set Multiplexer Control Commands

360 GPIB

Command

MP0 Set non-selected test set stand by power off
MP1 Set non-selected tes t set standby power on
RFA Set RF switch to A position

Definition

3-14 VIDEO SWITCH CONTROL

COMMANDS

Table 3-14 list the video output control commands
that control the internal 360 video switching paths.
These switching paths are shown in Figure 3-2.

The video output control commands perform the
same functions as the U7 menu selections. (The U7
menu is invoked from the VIDEO CONFIGURA­TION selection of the U1 Utility Menu; refer to the
360 Vector Network Analyzer Operation Manual.)

Table 3-14. Video Output Redirection Control Codes

360 GPIB

Command

VEE Video – External signa l to external m onit or
VEI Video – External signal to internal screen
VIE Video – Internal signal to external monitor
VII Video – Internal signal to internal screen

Definition

RFB Set RF switch to B position
SRA Set signal source to A
SRB Set signal source to B
TSA Set test se t to A
TSB Set test set to B

Figure 3-2. 360 VNA Video Signal Paths

360 GPIB PM 3-17

PULSE SYSTEM , NOISE FIG URE AN D
MILLIMETER-WAVE TEST SET COMMANDS III BASIC FRONT PANEL GPIB COMMANDS

3-15 PULSE SYSTEM COMMAND

The PMC mnemonic is the only command used with
the 360PS20A Pulsed VNA system. This command
provides control of the 3636A Pulsed/CW Test Set
pulse modulators by writing a control byte image to
the modulator c ontro l re gister of the test set (via the
360 VNA). Refer to the 360PS20A Pulsed/CW Vector
Network Analyzer Operation Manual for further in­formation about operation of the 360PS20A Pulsed
VNA system and system components.

The bit assignment of the register byte image is
shown in Figure 3-3; n ote that only the up per nibble
(i.e, four most significant bits) are used. If bit = 1,
the corresponding modulator will be turned on full
to override the profile pulse. If bit = 0, the profile
pulse will control the modulator. The example code
shown below is a prog ram fu nction to tur n o n all four
modulators. Note that byte is shown in hexadecimal
format (example is written in “C”.)

Example:

unsigned char control_byte;
ibwrt(pna, “PMC”, 3); /∗ send mnemonic

to 360 VNA ∗/

control_byte = 0xF0; /∗ all modulators

Ta, Ra, Tb, and
Rb full on ∗/

ibwrt(pna, &control_byte, 3); /∗ send

byte to 360 */

RbTbRaTa0000

76543210

3-16 NOISE FIGURE SYSTEM COMMANDS

The commands listed in Table 3-15 are used to
control the function s of the 3642A Noise Figu re Mod­ule and to read the status byte from that module.
The 3642A Noise Figure Module is part of the
360NF20A Noise Figure Vector Network Analyzer
System. Refer to the 360NF20A Noise Figure/Vector
Network Analyzer Operation Manual for informa­tion about the bit structure and bit functions of the
control registers affected by these commands.

Table 3-15. Noise Figure System Commands

360 GPIB

Command

MC1 (value) Write control byte to

MC2 (value) Write control byte to

RSB (value) Read Status Register (ID

Descri pt ion Values

3642A Noise Figure
Module Primary Control
Register

3642A Noise Figure
Module Secondary
Control Register

byte)

Binary,
8 bit

Binary,
8 bit

Binary,
8 bit

3-17 MILLIMETER-WAVE TEST SET

COMMANDS

The commands listed in Table 3-16 control the func­tions of the 3635A Millimeter Wave Test Set when
operated in the GPIB mode.

Table 3-16. Millimeter-Wave Test Set Commands

Upper Nibble Lower Nibble

Figure 3-3. Pulse System Control Byte Bit Structure

360 GPIB

Command

LDM Load new modules (must be specified for

the band and head changes that are to take
place). The mnemonic “LDM” must be

specified after band.
P2A Select model number 3640 “A” for port 2
P2B Select model number 3641 “B” for port 2
Q22 Select Q band (33-50 GHz) with WR-22
U19 Select U band (40-60 GHz) with WR-19
V15 Select V band (50-75 GHz) with WR-15
W10 Select W band (75-110 GHz) with WR-10

Description

3-18 360 GPIB PM

SECTION IV

COMMANDS FOR

CALIBRATION F UNCTIONS

Table of Contents

4-1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4-2 DESCRIPTION OF CALIBRATION COMMANDS . . . . . . . . . . . . . 4-3

Major Calibration Commands . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Required Calibration Command Sequence . . . . . . . . . . . . . . . . . . 4-4

Other Calibration Related Commands . . . . . . . . . . . . . . . . . . . . 4-4

A Simple E xample Calibration Program . . . . . . . . . . . . . . . . . . . 4-5

An Example HP-BASIC Subprogram . . . . . . . . . . . . . . . . . . . . 4-6

An Example “C” Program Function . . . . . . . . . . . . . . . . . . . . . 4-7

360 GPIB PM 4-1/4-2

SECTION IV

COMMANDS FOR

CALIBRATION F UNCTIONS

4-1 INTRODUCTION

This section describes the GPIB Product Specific
Commands used to perform system calibration fu nc­tions. In this section, these messages are referred to
as “360 GPIB commands” or simply “commands”.
These commands perform the following functions.

Specify the calibration method desired.

•

Specify the type of calibration desired.

•

Specify the calibration standards to be used.

•

Specify the transmission line type and associated

•

characteristics.
Control the calibration data-taking process.

•

4-2 DESCRIPTION OF CALIBRATION

COMMANDS

Table 4-2 located at the rear of this section lists all
GPIB commands that are used to perform the 360
VNA calibration func tion under remote c on trol. This
table provides a brief description of the function for
each command and lists permissible values and ter­minators, if required. Programming examples show­ing typical usage of these commands are provided in
paragraphs following the table.

NOTE

The 360 VNA calibration function
requires operator intervention. However,
it is possible to use the external c ontrolle r
to guide the operator thr ough the calibrat­ion process using a suitable program
containing the calibration commands de­scribed in this section.

a. Specify Normal 501 Point Calibration

(NOC)

This command sets up a normal frequency r ange
calibration.

b. Enter Start Frequency for Normal

Calibration (SRT)

This command sets the lower limit of the range
of frequencies used for the calibration process.

c. Enter Stop Frequency for Normal

Calibration (STP)

This command sets the upper limit of the range
of frequencies used for the calibration process.

d. Specify Discrete Frequency Calibration

(DFC)

This command sets up a calibration at discrete
frequencies only.

1. Only the points entered using the DFQ, IFV,
FRS, FRI, FRP, or FIL commands are used in
calibration (2 ≤ number of points ≤ 501) .

2. The IFV command allows for a frequency list
input of calibration frequencies. Refer to
paragraph 5-3, Data Transfer Commands, for
more details.

3. The DFQ, FRS, F RI, F R P, FIL, and DFO c om­mands can also be used to specify frequencies
outside of calibration.In this application, any
calibration data is lost.

e. Specify CW Calibration (CWC)

This command sets up a continuous wave (CW)
calibration.

4-2.1 Major Calibration Commands

The following paragraphs provide detailed descrip­tions of the major GPIB commands used for calibra­tion. They also provide programming information
and techniques for the use of these commands.

360 GPIB PM 4-3

f. Set up to Specify Port One Calibration

Standards (P1C)

This command specifies port one as the port to
which subsequent connector-related commands
will apply.

DESCRIPTION OF CALIBRATION COMMANDS IV CALIBRATION COMMANDS

g. Set up to Specify Port Two Standards

(P2C)

This command specifies port two as the port to
which subsequent connector-related commands
will apply.

Example:

“P1C CFK P2C CMK”

This sequence of commands sets up a female K
connector for port 1 (
connector for port 2 (

P1C CFK) and a male K

P2C CMK).

h. Other Connector Specification (CND)

This command allows a non-standard connector
to be specified. This is the same as selecting
OTHER from the control panel menu. When
specifying the CND command, the connector off­set for the open and/or short device and the ca­pacitance coefficients for the open device are en­tered to characterize the connector.

i. Specify Sliding Load for Calibration (SLD)

This command specifies a sliding load. If speci­fying the SLD command, the data-taking proces s

for the load includes six slide positions. If any
frequencies are below 2 GHz, you must use a
broadband load.

4-2.2 Required Calibration Command

Sequence

A program to control the calibration process must
use a specific order for the GPIB calibration com­mands. Table 4-1 lists t his acceptable order.

4-2.3 Other Calibration Related Commands

The following commands are used for special types
of calibrations and to simulate a calibration process.

a. A12, A8T, ARF, AFR, AFT, and ARL

These commands simulate the completion of a
calibration. When used in this manner, com­mands associated with calibration coefficients
(IC1–IC9, ICA–ICC, OC1–OC9, OCA–OCC) are
matched with the corr esponding err or terms. For
additional information, refer to Section V, para­graph 5-3, Data Transfer Commands.

Table 4-1. Calibration Command Ordering

Order Item Typical Commands Used Required / Optional

1 Calibration Method SCM, OCM, LCM O
2 Line Type LTC, LTW, LTU O
3 Waveguide Parameters WK1, WKD, WCO, SH1, SH2 O
3 Calibration Type C12, C8T, CRF, CFR, CFT, CFL R
4 Isolation Usage ISN, ISF O
5 Data Points NOC, DFC, TDC, CWG O
6 Frequency:

Range
Discrete *
CW

7 Connector Type , and

Offset Short Values

8 Load Type SLD, BBL O
9 Through Parameters TOL, TDL, TFL, TFE O

11 LRL Band LR2, LR3 O
12 LRL Parameters RM1, RRP, LL1, LL2, LL3, LM2, LM3, BPF O
13 Microstrip Parameters U10, U15, U25, USW, SBT, SBD, USE, USZ O
14 Begin Calibration (Data Collection) BEG R

∗ Required comm and s if DEC command previously issued. Command CND must be issued before sending CCO–CC3, and COS.

SRT, STP
DFQ, DFD, IFV, FRS, FRI, FRP, FIL, FRC
CWF

P1C, P2C, CMS, CFS, CMK, CFK, CMV,
CFV, CMC, CFC, CM2, CF2, CMN, CFN,
CM3, CF3, CNG, CND, COO, COS, CC0,
CC1, CC2, CC3, SH1, SH2

O
R
O

O

4-4 360 GPIB PM

IV CALIBRATION COMMANDS DESCRIPTION OF CALIBRATION COMMANDS

NOTE

The A8T, A12, ARF, AFR, AFT, and
ARL commands match up with corre­sponding calibration type commands.
These commands can be used for ad­vanced applications that input cali­bration coefficients into the 360 (refer
to Section V, paragraph 5-3).

b. CON and COF

These commands are not used during calibra­tion. They are used during normal measure­ments to apply the current calibration (CON) or
to turn off any applied calibration (COF).

c. LM2 and LM3

These commands are used to select a match for
the second or the third device respectively dur­ing a LRM type calibration. Example:

ibwrt(pna, “LM2", 3); /∗ match as second

device ∗/

d. U10, U15, and U25

These commands are used to select 10, 15, or 25
mil UTF calibration kits respectively. These cal i­bration kits are used to perform a 360 calibra­tion for microstrip device measurements. Exam­ple:

ibwrt(pna, “U10", 3); /∗ select 10 mil

calibration ∗/

4-2.4 A Simple Exam ple Cali brat ion

Program

The following is an example program to set up a
typical calibration sequence for the 360 VNA:

“SCM LTC C12 DFC FRS 1.0 GHZ FRI 100MHZ FRP
41 XX1 FIL DFD P1C CFK P2C CMK BBL BEG”

This example code sets up a calibration u sing stand­ard calibration mode (
and 12-term calibration type (

SCM), coax cable media (LTC),

C12). A discrete set of

points is defined for frequency operation starting at
1 GHz (

100MHZ

This range is confirmed or “filled” (
pleted (

FRS 1.0 GHZ), spaced 100 MHz apart (FRI

), at 41 consecutive points (FRP 41 XX1).

FIL), then com-

DFD).

The Port 1 test port connector is defined as a female
type K connector (
connector is defined as a male K type con ne ctor (

). Broadband loads are selected as the default

CMK

P1C CFK) and the Port 2 test port

P2C

load type (

BBL). The BEG command instructs the

360 to begin the calibration-data-taking-process.
The calibration control prog ram should contain com-

mands to control the data-collection portion of the
calibration process. Typical commands used for this
proces s are :

Take Calibration Data for Current Standard

•

(TCD)

Go on to the Next Calibration Step (NCS)

•

Averaging On and Set to Value (AVG)

•

Averaging Off (AOF)

•

Set IF Bandwith to Normal (IFN)

•

Set IF Bandwith to Reduced (IFR)

•

Set IF Bandwith to Minimum (IFM)

•

Any Graph Type Specification or Scaling Change

•

Active Channel Specification (CH1–CH4)

•

The TCD and NCS commands control the data-tak­ing process. Commands AVG, AOF, IFN, IFR, and
IFM control the data-enhanc ement func tion used for
a particu lar measuremen t (r efer to Section III, para­graph 3-6, Enhancement Commands).

Before the TCD and NCS commands are invoked in
the program, the system operator mus t be instr ucted
to perform the exact steps necessary to setup the
calibration sequence for the type of 360 calibration
to be used. An example program segme nt to continue
the 12-term calibration started in the previous
example is shown in Figure 4-1. This example pro­gram segment is in written in HP-BASIC.

The calibration control program should determine if
the 360 is ready for the next step of the calibration
sequence before prompting the system operator to
connect new calibration standards to the test ports.
This can be don e by mon itor in g the status of the 360
or by requesting “dummy” data output from the 360
after executing the NCS command.

For example, the command in the example below
instructs the 360 to take calibration data (TCD), go
to the next calibration step (NCS), and output the
number of points it is measuring (ONP). When the
controller is able to read the points string from the
360, the calibration step is complete.

260 OUTPUT 706;"TCD NCS ONP"
270 ENTER 706; N$ ! READ #POINTS WHEN
STEP IS COMPLETE
280 DISP “CALIBRATION STEP COMPLETE”

360 GPIB PM 4-5

EXAMMPLE CALIBRATION PROGRAMMING IV CALIBRATION COMMANDS

4-2.5 An Example HP-BASIC Subprogram

A listing of an example calibration subprogram is
shown in Figure 4-1. This program guides the 360
system operator through a 12 term calibration
sequence. Th e calibration is perfo rmed at 41 discr ete
frequencies with 100 MHz spacing from 1 to 5 GHz
(see explanation o f lin e 330 in pr ec edin g par ag r aph ).

290 ! —-CALIBRATION SUBPROGRAM—­300 !
3l0 SUB Cal_l2_term(@vna)
320 PRlNT TABXY(35,1);"CALIBRATION"
330 OUTPUT @vna; “LTC SCM C12 DFC FRS 1 GHZ FRI 100 MHZ FRP 41 XXl FIL

DFD P1C CFK P2C CMK BBL BEG ONP”
340 ENTER @vna;N$
350 DISP “CONNECT BROADBAND LOADS TO PORT 1 AND PORT 2"
360 GOSUB Continue
370 DISP “CONNECT OPEN TO PORT 1 AND SHORT TO PORT 2"
380 GOSUB Continue
390 DISP “CONNECT SHORT TO PORT 1 AND OPEN TO PORT 2"
400 GOSUB Continue
410 DISP “CONNECT PORT 1 TO PORT 2"
420 GOSUB Continue
430 DISP “l2 TERM CALIBRATION COMPLETE”
440 SUBEXIT
450 Continue: BEEP
460 LOOP
470 ON KEY 5 LABEL “TAKE CAL DATA” GOTO 490
480 END LOOP
490 DISP “TAKING CALIBRATION DATA...”
500 OUTPUT @vna;"TCD NCS ONP"
510 ENTER @vna;N$
520 RETURN
530 SUBEND
540 !

In this example, the same technique is used as de­scribed in paragraph 4-2.4 to determine if the 360 is
ready for the next calibration step.

An example of a main program that calls this and
other subprograms is described in application note,
AN360-9, which is includ ed be hind the Supp lemen t s
tab in this manual.

Figure 4-1. Example Program Segment to Control Calibration Data Collection (HP BASIC)

4-6 360 GPIB PM

EXAMPLE CALIBRATION PROGRAMMING IV CALIBRATION COMMANDS

4-2.6 An Example “C” Program Function

An example “C” program function, “cal_12_term()”,
is shown in Figure 4-2. This program function per­forms the same calibration sequence described in
paragraphs 4-2.4 and 4-2.5. In this example, the
program function “cal_data()” instructs the 360 to

/*————————————————————————————-
Calibration Function
Setup for a 12-Term Calibration and prompt the operator
to install cal devices as required.
————————————————————————————-*/
cal_12_term(vna)
int vna;
{
static char
a[]="LTC SCM C12 DFC FRS 1 GHZ FRI 100 MHZ FRP 41 XX1",
b[]="FIL DFD P1C CFK P2C CMK BBL BEG ONP",
point_str[40];

printf(“\n\t\t\t\tCALIBRATION\n”);
ibwrt(vna,a,sizeof(a));
ibwrt(vna,b,sizeof(b));
ibrd(vna,point_str,40);
printf(“\nConnect BROADBAND LOADS to Port 1 and Port 2:\n”);
cal_data(vna);
printf(“\nConnect OPEN to Port 1 and SHORT to Port 2:\n”);
cal_data(vna);
printf(“\nConnect SHORT to Port 1 and OPEN to Port 2:\n”);
cal_data(vna);
printf(“\nConnect Port 1 to Port 2:\n”);
cal_data(vna);
printf(“\n\t\t 12-Term Calibration Complete\n”);
}

take calibration data (TCD) and advan ce to the next
step (NCS) after determining if the 360 is ready.

An example of a main program that calls this and
other subprograms is described in the application
note, AN360-8, w h ich is in c luded behind the Supple­ments tab in this manual.

cal_data(vna) /* function to take cal data */
int vna;
{
static char
key,
c[]="TCD NCS ONP",
point_str[40];

printf(“\tPress ENTER key to Take Cal Data\n”);
while((key = getch())!=’\r’);
printf(“Taking Calibration Data...\n”);
ibwrt(vna,c,sizeof(c));
ibrd(vna,point_str,40);
}

Figure 4-2. Example “C” Program Function to Perform a 12 Term Calibration

360 GPIB PM 4-7

DESCRIPTION OF CALIBRATION COMMANDS IV CALIBRATION COMMANDS

Table 4-2. Calibration Commands (1 of 4)

360 GPIB

Command

A8T Simulate 8-term (1-path) calibration N/A N/A
A12 Simulate 12-term calibration N/A N/A
AFR Simulate frequency response calibration N/A N/A
AFT Simulate transmission-only frequency

response calibration
ARF Simulate reflection only calibration N/A N/A
ARL Simulate reflection-only frequency response

calibration
BBL Select broadband load for calibration N/A N/A
BEG Begin calibration data-collection steps N/A N/A
BPF (value) Break point frequency for 3 line LRL only Start sweep frequency to

C8T Select 8-term (1-path) calibration N/A N/A
C12 Select 12-term calibration N/A N/A
CC0 (value)

CC3 (value)

Enter capacitance coefficients 0-3 for open

for user-specified connector

Description Values Terminators

N/A N/A

N/A N/A

GHZ, MHZ, KHZ

stop sweep frequency

–9999.99 to +9999.99 XX1

CF2 Select female 2.4 mm connector for current

port
CF3 Select female GPC-3.5 connect or for curre nt

port
CFC Select female TNC connector for current port N/A N/A
CFK Select female K connector for current port N/A N/A
CFN Select female Type N connector for current

port
CFR Select transmission and reflection frequency

response calibration
CFS Select female SMA connector for current

port
CFT Select transmission-only frequency

response calibration
CFV Select female V connector for current port N/A N/A
CM2 Select male 2.4 mm connector for current

port
CM3 Select male GPC-3.5 connector for current

port
CMC Select male TNC connector for current port N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

CMK Select male K connector for current port N/A N/A

4-8 360 GPIB PM

IV CALIBRATION COMMANDS DESCRIPTION OF CALIBRATION COMMANDS

Table 4-2. Calibration Commands (2 of 4)

360 GPIB

Command

CMN Select male Type N connector for current

port
CMS Select male SMA connector for current port N/A N/A
CMV Select male V connector for current port N/A N/A
CND Select user-specified connector for current

port
CNG Select GPC-7 connector for current port N/A N/A
COF Turn off vector error correction N/A N/A
CON Turn on vector error correction N/A N/A
COO (value) Enter offset for open for user-specified

connector
COS (value) Enter offset for short for user-specified

connector
CRF Select reflection only calibration N/A N/A
CRL Select reflection-only frequency response

calibration
CWC Select CW frequency calibration data points N/A N/A

Description Values Terminators

N/A N/A

N/A N/A

–999.9999 to +999.9999 MMT, CMT, MTR

–999.999 m to 999.999 m MMT, CMT, MTR

N/A N/A

DFC Select discrete frequency calibration data

DFD Done specifying discrete frequency ranges N/A N/A
DFQ (value) Enter single discrete frequency Start sweep frequency to

FIL Fill defined discrete frequency range N/A N/A
FRC Clear all defined discrete frequency ranges N/A N/A
FRI (value) Set discrete frequency fill range increment

FRP (value) Set discrete frequency fill range number of

FRS (value) Set discr ete f requency fill range start

ISF Exclude isolation N/A N/A
ISN Include isolation N/A N/A
KEC Keep existing calibration data N/A N/A
LCM Select LRL calibration method N/A N/A
LL1 (value) Enter length of line 1 for LRL calibration 0 to +999.9999 MMT, CMT, MTR

points

frequency

points

frequency

stop sweep frequency

Start sweep frequency to

stop sweep frequency

1 to (501 — current
number of points)

Start sweep frequency to

stop sweep frequency

N/A N/A

GHZ, MHZ, KHZ

GHZ, MHZ, KHZ

XX1, XX3, XM3

GHZ, MHZ, KHZ

LL2 (value) Enter length of line 2 for LRL calibration 0 to +999.9999 MMT, CMT, MTR

360 GPIB PM 4-9

DESCRIPTION OF CALIBRATION COMMANDS IV CALIBRATION COMMANDS

Table 4-2. Calibration Commands (3 of 4)

360 GPIB

Command

LL3 (value) Enter length of line 3 for 3 line LRL

calibration
LLZ (value) Enter line impedance for LRL calibration 0.001 to 1x10E+3 XX1, XX3, XM3
LM2 Select a match for the second device during

a LRM type calibration
LM3 Select a match for the third device during a

LRM type calibration
LR2 Specify 2 line LRL N/A N/A
LR3 Specify 3 line LRL N/A N/A
LTC Select coaxial transmission line for

calibration
LTU Select microstrip transmission line for

calibration
LTW Select waveguide transmission line for

calibration
NCS Go on to next calibration step N/A N/A
NOC Select normal calibration data points

This code

Description Values Terminators

0 to +999.9999 MMT, CMT, MTR

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

OCM Select o ffset short calibration method N/A N/A
P1C Select port 1 for connector specification N/A N/A
P2C Select port 2 for connector specification N/A N/A
RGZ Select reflective device greater than Z0

RLZ Select reflective device less than Z0 (LRL) N/A N/A
RM1 Select reference plane at line 1 midpoint

ROL (value) Enter reflective device offset length for LRL

RPC Repeat previous calibration N/A N/A
RRP Select reference plane at reflection plane

SBD (value) Enter substrate dielectric for microstrip

SBT (value) Enter substrate thickness for microstrip

SCM Select standard calibration method N/A N/A

(LRL)

(LRL)

–999.999 to +999.999 MMT, CMT, MTR

calibration

(LRL)

calibration

0.001 mm to 1 .0 m MMT, CMT, M TR

calibration

N/A N/A

N/A N/A

N/A N/A

1.0 to 9999.99 XX1, XX3, XM3

4-10 360 GPIB PM

IV CALIBRATION COMMANDS DESCRIPTION OF CALIBRATION COMMANDS

Table 4-2. Calibration Commands (4 of 4)

360 GPIB

Command

SH1 (value) Set offset short 1 offset length –999.999 to +999.999 MMT, CMT, MTR
SH2 (value) Set offset short 2 offset length –999.999 to +999.999 MMT, CMT, MTR
SLD Select sliding load for calibration N/A N/A
TCD Take calibration data for current standard N/A N/A
TDC Select time domain harmonic frequency

calibration data points
TDL (value) Through DC coefficient for loss –999.999 to +999.999 XX1
TFE (value) Through frequency exponent for loss –9.999 to +9.999 XX1
TFL (value) Through frequency coefficient for loss –999.999 to +999.999 XX1
TOL (value) Through offset length –999.9999 to +999.9999 MMT, CMT, MTR
U10 Select 10 mil UTF calibration kit for

calibration for microstrip device

measurements
U15 Select 15 mil UTF calibration kit for

calibration for microstrip device

measurements
U25 Select 25 mil UTF calibration kit for

calibration for microstrip device

measurements

Description Values Terminators

N/A N/A

N/A N/A

N/A N/A

N/A N/A

USE (value) Enter effective dielectric for microstrip

calibration
USW (value) Enter microstrip width for microstrip

calibration
USZ (value) Enter microstrip impedance for microstrip

calibration
WCO (value) Set waveguide cutoff frequency for user-

defined kit
WKD Select user-defined wa veguide c alibration kit N/ A N/A
WKI Select installed waveguide calibration kit N/A N/A

1.0 to 9999.99 XX1, XX3, XM3

0.001 mm to 1 .0 m MMT, CMT, M TR

1.0 to 9999.99 XX1, XX3, XM3

0 to current start frequency GHZ, MHZ, KHZ

360 GPIB PM 4-11/4-12

SECTION V

ADVANCED GPIB PROG RAMMING

AND GPIB UNIQUE FUNCTIONS

Table of Contents

5-1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5-2 SAVE/RECALL COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5-3 DATA TRANSFER COMMANDS . . . . . . . . . . . . . . . . . . . . . . . 5-4

Descriptions of Data Transfer Commands . . . . . . . . . . . . . . . . . . 5-7

Data Transfer Program Example and Program Notes . . . . . . . . . . 5-10

5-4 GROUP EXECUTE TRIGGER COMMANDS . . . . . . . . . . . . . . . 5-13

5-5 DISK FUNCTION COMMANDS . . . . . . . . . . . . . . . . . . . . . . 5-14

5-6 SRQ STATUS BYTE STRUCTURE AND COMMANDS . . . . . . . . . 5-16

Primary Status Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

Secondary Stat us Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5-7 TIME DOMAIN COMMANDS . . . . . . . . . . . . . . . . . . . . . . . 5-20

5-8 MULTIPLE SOURCE CONTROL COMMANDS . . . . . . . . . . . . . 5-20

5-9 SWEEP CONTROL COMMANDS . . . . . . . . . . . . . . . . . . . . . 5-21

5-10 REAR PANEL OUTPUT CONTROL COMMANDS . . . . . . . . . . . . 5-21

5-11 SCREEN DRAW COMMANDS . . . . . . . . . . . . . . . . . . . . . . . 5-23

5-12 RECEIVER MODE COMMANDS . . . . . . . . . . . . . . . . . . . . . 5-23

360 PM 5-1/5-2

SECTION V

ADVANCED GPIB PROG RAMMING

AND GPIB UNIQUE FUNCTIONS

5-1 INTRODUCTION

This section describes the GPIB Product Specific
Commands that produce operations that are unique
to the GPIB mode of operation. Example commands
included in this group are: Data Tr ansfer commands,
Group Execute commands, etc. (see Table of
Contents, page 5-1). In this section, these messages
are referred to as “360 GPIB commands” or simply
“commands”.

Table 5-1. Save/Recall Commands

360 GPIB

Command

SV1-SV4 Save front panel setup to internal memory

location 1-4

Description Values Terminators

5-2 SAVE/RECALL COMMANDS

The Save/Recall commands listed in Table 5-1 allow
the system user to save and recall:

• (1) front panel setup data to and from internal
memory, and

(2) calibration and front panel setup data to/from

•

the disk. The syntax for entering a file name
string to the 360 is the same as the syntax for the
strings in the LMS, LID, LDT and LNM com­mands described in Section III, paragraph 3-11.

The double quote characters must enclose the string
sent to the 360. The 360 accepts only MS-DOS
compatible file name characters. Refer to paragraph
5-5, Disk Fun ction Comman ds, for more inf or ma tion
about file naming conventions.

N/A N/A

RC1-RC4 Recall front panel setup data from internal

memory location 1-4

360 GPIB PM 5-3

N/A N/A

DATA TRANSFER COMMANDS V ADVANCED GPIB PROGRAMMING

5-3 DATA TRANSFER COMMANDS

T able 5-2 desc ribes the data tran sfer c ommands. The
360 transfers data to/from an external computer via
the GPIB in two basic formats: binary and ASCII.
All ASCII data values either output by the 360 or
expect ed as i nput must have the following form:

Where:

S

x x x . y y y y y y y y y y y y y y y E s z z

S = sign, either blank or “–”
x = digits to the left of the decimal (3)

y = digits to the right of the decimal (15)
E = exponential notation indicator
s = exponent sign, either ’+’ or ’–’
z = digits for exponent (2)

.

= decimal point

Separate all ASCII transfers that involve data pairs
(such as real and imaginary elements) by commas.
For transfers involving more than one item of infor­mation, separate each item by a line feed.

For example, the 360 response to the commands
“FMA OCD” would be:

(Repeated Number of Points)

Real ASCII>, <Imaginary ASCII

<

EOI on Last Byte

<LF>

>

Binary data transfers involving numerical values
use 32-bit or 64-bit floating point numbers in
IEEE-754 format. The format of string data, such as
that used for front panel setup data, is not user
controllable. Binary da ta is alway s sen t in the stand­ard block format shown in Figures 5-1 and 5-2.

The data-format commands (FMA, FMB and FMC)
and the byte-ordering commands (LSB and MSB)
control the format of the data that is input or outpu t
by the 360 VNA under control of many of the data
transfer commands (Table 5-2). However, the com­mands that transfer binary data strings and ASCII
data are not affected by the data format and byte­ordering commands. (These commands always in­put/output binary data strings and ASCII data re­gardless of the curren tly selec ted data format.) Refe r
to Table 5-2 and Figure 5-2 for details.

LSB MODE:

#A

Standard Preamble Bytes

MSB MODE:

#A

Standard Preamble Bytes

Least

Significant

Significant

Figure 5-1. Binary Data Transfer Message Format

Byte Count Byte Count Bytes

Most

Significant

Byte

Byte Count Byte Count Bytes

Most

Byte

Byte

Least

Significant

Byte

Least Significant Byte

First for All Elements

EOI Coincidental With
The Last Byte

Least Significant Byte

First for All Elements

EOI Coincidental With
The Last Byte

Binary Data

Binary Data

5-4 360 GPIB PM

V ADVANCED GPIB PROGRAMMING DATA TRANSFER COMMANDS

Standard

Preamble

# A LSB, MSB

1

byte1byte

Byte Count

2

bytes

Element 1, S21 Mag & Phase Element 501, S21 Mag & Phase





LSB . . . MSB



dB

4

bytes

Deg

LSB . . . MSB

4

bytes

– – –

dB

LSB . . . MSB

4

bytes

LSB . . . MSB

Deg

4

bytes

BYTE COUNT = 8 bytes x 501 data points = 4008 bytes

(“Byte Count” bytes will contain the value 4008.)

Figure 5-2. Example of Binary Data Transfer

Table 5-2. Data Transfer Commands (1 of 2)

360 GPIB

Command

CCD Collect corrected data for parameter of active channel 5-3 m. N/A
CFD Collect final (display format) data for parameter of active channel 5-3 m. N/A

Brief Description

Descript.

(Para.)

Data Formats

CRD Collect raw data for parameter of active channel 5-3 m. N/A
FMA Select ASCII data transfer format 5-3 e. N/A
FMB Select IEEE-754 64-bit data transfer format 5-3 e. N/A
FMC Select IEEE-754 32-bit data transfer format 5-3 e. N/A
IC1 (value) –

IC9 (value)
ICA (value),

ICB (value),
ICC (value)

ICD (value) Input corrected data for parameter of active channel 5-3 l. FMA, FMB, FMC
ICF (Binary string) Input information for front panel setup

ICL (Binary string) Input all 12 calibration coefficients in binary string format 5-3 g. Binary string
IFD (value) Input final (display format) data for parameter of active channel 5-3 l. FMA, FMB, FMC
IFP (Binary string) Input information for current front panel setup in binary string

IFV (value) Input frequency list 5-3 h. FMA, FMB, FMC
IS1 (Binary string) –

IS4 (Binary string)

Input calibration coefficient 1-9 5-3 g. FMA, FMB, FMC

Input calibration coefficient A, B, C 5-3 g. FMA, FMB, FMC

and

string format

calibration in binary

format

Input information for front panel setups in binary string format 5-3 i. Binary string

5-3 n. Binary string

5-3 i. Binary s tring

360 GPIB PM 5-5

V GPIB OPERATION — ADVANCED PROG RAMM ING DATA TRANSFER COM MAND CO DES

Table 5-2. Data Transfer Commands (2 of 2)

360 GPIB

Command

LSB Select least significant byte first binary transfers 5-3 f. N/A
MSB Select most significant byte first binary transfers 5-3 f. N/A
OAP (value) Output active parameter value 5-3 b. ASCII
OC1 (value) –

OC9 (value)
OCA (value),

OCB (value),
OCC (value)

OCD (value) Output corrected data for parameter of active channel 5-3 l. FMA, FMB, FMC
OCF (Binary string) Output information for front panel setup

OCL (Binary string) Output all 12 calibration coefficients in string form 5-3 g. Binary string
OCS Output collected data 5-3 m. N/A
ODR (Binary string) Output disk directory 5-3 k. Binary string
OFD (value) Output final (disp. format) data for parameter of active channel 5-3 l. FMA, FMB, FMC
OFP (Binary string) Output information for current front panel setup in binary string

Output calibration coefficient 1–9 5-3 g. FMA, FMB, FMC

Output calibration coefficient A, B, C 5-3 g. FMA, FMB, FMC

string format

format

Brief Description

and

calibration in binary

Descript.

(Para.)

5-3 o. Binary string

5-3 j. Binary s tring

Data Formats

OFV (value) Output frequency values 5-3 h. FMA, FMB, FMC
OID (value) Output instrument identification string 5-3 d. 40 byte ASCII strg
OKP (value) Output number of front panel key pressed 5-3 c. ASCII
OM1 (value) –

OM6 (value)
ONP (value) Output number of points currently being measured 5-3 p. ASCII
ORD (value) Output raw data for parameter of active channel 5-3 l. FMA, FMB, FMC
OS1 (Binary string ) –

OS4 (Binary string)

The most important points to consider about data
transfer are (1) the data format to use and (2) the
byte ordering desired. When using the FMA data
format, the byte ordering selected by the LSB or

Output marker 1-6 value (display format) 5-3 a. ASCII

Ouput information for front panel setups (1–4) in binary string
format

5-3 j. Binary s tring

active byte ordering. Conversely, even if you select
FMB or FMC data format, some transfers will al­ways occur in ASCII and are unaffected by the LSB
or MSB commands.

MSB commands is irrelevant.

NOTE

ASCII data is not dependent on the active byte order .
However, even if the 360 is using FMA format, some
transfers ( suc h a s the O S1–O S4 commands) still use
the binary transfer format, which is affected by the

The byte ordering mode (LSB or MSB)
also affects the orde r of the tw o by tes th at
comprise the byte count portion of the
standard preamble (Figure 5-1.)

5-6 360 GPIB PM

V ADVANCED GPIB PROGRAMMING DATA TRANSFER COMMANDS

Table 5-3. Output Values Vs Various Graph Types

Display Type Output Values

Log magnitude dB, degrees
Phase dB, degrees
Log mag & phase dB, degrees
Linear magnitude Lin Mag (Rho or Tau), degrees
Linear mag & phase Lin Mag (Rho or Tau), degrees
Smith chart Ohms, Ohms (r + jx)
Inverted Smith Siemens, Siemens (g + jb)
Group delay Seconds, degrees
Log polar dB, degrees
Linear polar Lin Mag (Rho or Tau), degrees
Real Real, imag
Imaginary Real, imag
Real & Imaginary Real, imag
SWR SWR, D egree s

5-3.1 Descriptions of Data Transfer

Commands

A detailed description of each of the data transfer
commands follows:

a. OM1 - OM 6

These commands output the value of the trace
on the active chan n el at mark er 1–6. Th e outpu t
is always a pair of ASCII values and is depend­ent upon the graph type used for the active chan ­nel (See Table 5-3).

b. OAP

This command outputs the value of the active
parameter as a single ASCII valu e. If the re is no
active parameter, a zero value is output.

c. OKP

This command outputs a single ASCII value
representing the number of the key pressed on
the front panel of the 360 VNA.

d. OID

This command outputs a 40-byte ASCII string
defining the current 360 VNA system configura­tion. The format of the OID string is shown in
Table 5-4.

Table 5-4. OID Response String

Number of Bytes

4 9 9 666

xxxx

Model

No.

xx.xxxxxx

Low

Freq.

GHZ

xx.xxxxxx

High

Freq.

GHZ

Sxx.x

Low
Pwr

dBM

Sxx.x

High

Pwr

dBM

xxx.xx

S.W.
Rev.

e. FMA, FMB, F MC

These commands set up the current active data
transfer format.When the current transfer for­mat is unknown, it is a good practice to precede
any data transfer commands which depend on
these formats with the desired format c ommand.

f. LSB, MSB

These two commands control the ordering of
bytes for floating point data transfer s. Th ey also
control the ordering of the two bytes that
comprise the byte count in the standard block
header for binary data transfers. LSB specifies
that transfers are to be least significant byte
first while MSB specifies most significant byte
first.

g. IC1-IC9, ICA, ICB, ICC, OCL, ICL,

OC1–OC9, OCA, OCB, OCC

These commands provide for calibration coeffi­cient transfers. Table 5-5 shows the ordering of
the calibration coefficients for various calibra­tion types. For example, if you desire the ETF
error term from an 8-ter m calibr ation, y ou wou ld
use the OC4 or IC4 commands.

NOTE

Calibration coefficients are output, or
expected as input, only for the
currently defined set of sweep fre­quencies. If data points are not at
maximum and/or the frequency range
has been zoome d-in ( with error co rrec­tion turned on), not all calibration co­efficients will be output or used as
input.

If a request is made for an unavailable calibrat­ion coefficien t array, the 360 VNA treats it as an
impossible request and ignores the command.

360 GPIB PM 5-7

DATA TRANSFER COMMANDS V ADVANCED GPIB PROGRAMMING

h. OFV, IFV

The OFV command outputs the current 360
VNA measurement frequencies.

The IFV command can be used to input an
arbitrary list of frequencies into the 360 VNA
(2 ≤ number of frequencies ≤ 501). This code
can be used to spec ify a set of fre quencies to used
for calibration (after a calibration type has bee n
specified). Comman d IF V can a lso be used in the
normal measurement mode to input frequencies
for a special application. In this usage, any ex­isting calibration data is lost.

i. IFP, IS1–IS4

These commands input a binary string of data
as information f or store d setups (I S1– IS4), or a s
information for the current front panel setup
(IFP). The data string mus t be exactly the length
of the string output by the OFP or OS1–OS4
commands and is checked for validity before the
operation is performed. If either the number of
bytes, or the contents of the string are invalid, a
parameter out of range error is generated.

For the IFP command, if the setup data is valid
the 360 VNA will change its setup based on the
new front panel setup information.

j. OFP, OS1–OS4

These commands output a binary string of data
from either one of the four stored setups (OS1–
OS4) or from the current front panel setup
(OFP). The size of a fron t panel setup is 3 kBytes
(3072 bytes).

k. ODR

This command ou tputs a binar y str ing that is an
image of the directory table of the current disk
mounted in th e floppy disk drive of the 360 VNA.
If a disk error occurs, the 360 does a disk-error­status-update and transfers no data. The data
string for the directory is exactly 3.5 kBytes
(3584 bytes) long.

l. ICD, IFD, ORD, OCD, OFD

These commands transfer data for the
S-parameter o n the active channel. O nly the cur-
rent measurement points will be output (ORD,
OCD, OFD) or expected as input (ICD, IFD).

1. The ORD and OCD commands both output
data for the parameter on the active channel
in (real, imaginary) pairs (real, imaginary).
Similarly, ICD expects corrected data for the
parameter on the active chan n el in pair s.

2. The OFD command outputs data values for
the parameter on the active channel that de­pend on the current graph type being used
(see Table 5-3). The IFD command expects the
data being input to match the graph type on
the active chann el in the same way.

3. When parameter data input to the 360 VN A is
complete (ICD and IFD) the 360 redraws the
parameter on the active channel using this
data. To prevent the newly drawn data from
being overwritten by new measurement data
the instrument should be in hold prior to in­putting the data.

m. CRD, CCD, CFD, OCS

The CRD, CCD , and CFD commands co llec t data
in the current data format for the parameter on
the active chann el until either another comman d
is received or data buffer space has been ex­hausted. The OCS command outputs the col­lected data.

NOTE

Any comman d after the CRD , CCD, or
CFD commands will terminate the
collection mode. This includes Group
Execute Triggers (GETs) defined us­ing the DEF...END commands. Meas­urement trigger GETs set up by the
TIB command are permitted. Error
correction must be turned off before
executing CRD.

Upon receipt of the CRD, CCD, or CFD com­mand the 360 VNA will:

1. Clear bit 7 of the main status register.

2. Abort any current sweep.

3. Set up for the collection sweep.

When the system is ready to begin a new sweep,
bit 7 of the main status register is set. If the
instrument is in CW mode, it will phase lock at
that frequency before bit 7 of the main status
register is set. The number of data points that
can be collected is determin ed by th e data for mat
shown in Table 5-6.

n. ICF

This command inputs a binary string of data as
information for the current front panel setup
and calibration.

5-8 360 GPIB PM

V ADVANCED GPIB PROGRAMMING DATA TRANSFER COMMANDS

o. OCF

This command outputs the current front panel
setup and calibration information in binary
string data format.

p. ONP

This command outputs the number of data

Tab le 5-6. Maximum Data Points vs Data Format

Data Format

FMC (32-bit) 6137
FMB (64-bit) 3068
FMA (ASCII) 983

Maximum Number of

Collected Points

points curren tly being measured by the 360 VNA
as a single ASCII value.

Table 5-5. Calibration Coefficient Ordering

Calibration Type

Coefficient#12-Term

C12

1 EDF EDF EDF ERF ETF ERF –
2 ESF ESF ESF ETF – – –
3 ERF ERF ERF – – – –
4 EXF ETF – – – – –
5ELF––– – – –

8-Term

C8T

Reflection

Only
CRF

Frequency

Response

CFR

Transmission

Freq. Response

CFT

Reflection

Freq. Response

CRL

None

6ETF––– – – –
7 EDR – – – – – –
8 ESR – – – – – –

9 ERR – – – – – –
A EXR – – – – – –
B ELR – – – – – –

C ETR – – – – – –

360 GPIB PM 5-9

DATA TRANSFER COMMANDS V ADVANCED GPIB PROGRAMMING

5-3.2 Data Transfer Program Example and

Program Notes

a. Data Transfer Example

Figure 5-3 is a listing of an example program
written in Microsoft “C”. It uses a number of
data transfer commands as well as various com­mands from Section III. The program is written
to run on an IBM-PC or compatible computer
with a National Instruments GPIB-PCIIA board
and “C” language interface drivers. The func­tions performed by the program are:

Reset the 360 to its default state.

•

Read a full array of frequencies from the 360.

•

Input a subset of these frequencies into the

•

360.
Take S21 transmission data.

•

Loop this data back in to the 360 as e rror term

•

ETF for a transmission frequency response
calibration.

Turn on correction in the 360 and read in a

•

full corrected sweep of data using this as the
error term.

Print the results on the computer screen.

•

b. Data Transfer Program Notes:

This program uses a large time-ou t value (100

•

seconds). This prevents the controller from
quitting while the 360 is busy. For example,
after sending “TRS WFS FMC LSB ORD”
, enough time must be allocated to allow the
360 to complete a new sweep and format the
data for output.

A structure was defined (struct std_header)

•

for manipulatin g the standard block he ader so
that message byte counts are easily accessed

.

All transfers use LSB mode to be compatible

•

with INTEL microprocessors.
FMB is equivalent to “double” in “C”, FMC

•

is equivalent to “float”.
Before measurement data is read from the

•

360, the controller sends a “WFS” command
to ensure the data is valid.

Reads can be terminated by (1) reading the

•

header and th en using the by te count valu e or
(2) by specifying a maximum value for the
transfer count and letting the transfer termi­nate when the 360 sets the EOI line sign alin g
the end of information.

The program defines a structure for the S21

•

(mag, phase) data pairs output by the 360 for
the OFD command. This allows for easy ac­cess to each frequency point’s two data values
using array indexing.

The AFT command must be sent before the

•

IC1 command so that the 360 can discern
what calibration coefficient #1 corresponds to
(ETF in this example).

It is good practice to preface a data transfer

•

command with a format and byte-order com­mand (ie., “FMB LSB OFV”), although both
the format and the byte-order carry on to the
next transfer.

A section of a string may be read (such as the

•

header) followed by the remainder of the
string. Howeve r the entire data stream must

be read before any subsequent data will be
available.

5-10 360 GPIB PM

V ADVANCED GPIB PROGRAMMING DATA TRANSFER COMMANDS

Figure 5-3. A “C” Language Example Program for Data Transfer Using the 360 (1 of 2)

360 GPIB PM 5-11

DATA TRANSFER COMMANDS V ADVANCED GPIB PROGRAMMING

Figure 3-4. A “C” Language Example Program for Data Transfer Using the 360 (2 of 2)

5-12 360 GPIB PM

V ADVANCED GPIB PROGRAMMING GROUP EXECUTE TRIGGER COMMANDS

5-4 GROUP EXECUTE TRIGGER

COMMANDS

The 360 is extremely flexible in its implementation
of group execute trigger (GET) functions. The two
360 GPIB commands specifically designated for im­plementing the normal group execute trigger func-
tions are D EF and END (Table 5-7). However, almost
all 360 GPIB commands—in any combination—can
be set up as part of the DEF—END response to the
receipt of a GET (IEEE-488 interface function mes­sage) from the external computer.

NOTE

The DEF—END response to the receipt of
a GET interface function message is
turned-off by the receipt of the TIB com­mand earlier in the program. (The TIB
command provides a sweep trigger upon
receipt of a GET interface function mes­sage—refer to paragraph 5-9.)

The response to the GET interfac e func tion message
is set up by issuing the DEF command followed by
a sequence of commands terminated with the END
command. The sequence may be comprised of any
sequence of 360 GPIB commands that does not in­clude a data input command. If a data input com­mand is included, the 360 reads the data as addi­tional commands. This usu ally cause s a syntax error
to be issued. The entire DEF—END string is pre­parsed and compacted. The maximum compacted
string size is 255 characters.

An example of the use of the DEF and END com­mands is shown in the following command string:

“DEF CFT NOC SRT 1 GHZ STP 18 GHZ BEG TCD
NCS MR1 WFS MMX OM1 MMN OM1 END”

When this sequence of commands is sent to the 360,
it is stored as the response to the group execute
trigger. The commands between the DEF and END
commands will not be execu ted as part of the normal
program flow. The DEF—END sequence will be

executed every time the 360 receives a GET inter­face function message from the external computer
provided that a TIB command has not been issued
earlier in the program. For the example shown
above, the 360 will perform the following sequence
every time it is triggered by a GET interface function
message:

• Perform a transmission frequency response cali­bration from 1 to 18 GHz (

STP 18 GHZ BEG TCD NCS

• Turn on marker (

MR1).

• Wait for a full sweep of data (

CFT NOC SRT 1 GHZ

).

WFS).

• Move marker 1 to the maximum value on the
trace (

• Output the maximum value (

MMX).

OM1).

• Move marker 1 to the minimum v alue on the trace
(

MMN).

Output the minimum value (

•

OM1).

Thus, every time the 360 receives a GET interface
function message , it outputs the maximum and
minimum values for the new calibration just per­formed.

NOTE

1. When the 360 VNA is triggered via the

GPIB, the 360 puts the trigger command
(GET) into the command buffer behind
any preceding instructions. The com­mands in the DEF ... END string are exe­cuted upon completion of the commands
issued prior to the GET command.

2. When the TIB = GPIB coding method
is used for measur ement tr iggering , group
execute triggers will not execute the com­mands in the DEF... END string. The
group execu te trig ger will initiate a meas­urement. See paragraph 5-9, Sweep Con­trol Commands, for more details.

Table 5-7. Group Execute Trigger Commands

360 GPIB

Command

DEF Begin definition of group execute trigger action N/A
END End definition of group execute trigger action N/A

Description Data Formats

360 GPIB PM 5-13

DISK FUNCTION CO MM ANDS V ADVANCED GPIB PROGRAMMING

5-5 DISK FUNCTION COMMANDS

The Disk Function commands listed in table 5-6 are
used for the following:

• Reading files from the disk.

• Writing files to the disk.

• Deleting files.

• Formatting a data-only disk.

Loading c alibration kit information f ro m th e disk.

•

All of the Disk Function commands, except the INT
and LKT commands, require a file name string. File
name strings can be up to 8 characters long and
must be enclosed by double quote characters (“); see
the descriptions of the LMS, LDT, LID, and LNM
commands in Section III, paragraph 3-11. Examples
of the disk function commands usage are shown in
Figure 5-4.

The TDD and TTB commands enable the user to
store tabular data to the disc and recall it for output
to the printer with the tabular printout points con­trolled by commands PT0–PT9 (Commands PT0–
PT9 are described in Section III, paragraph 3-11).

NOTE

The maximum file size that can be
handled with the RTB command is 58
kbytes.

Only file name characters accepted by MS-DOS are
valid for use with these commands. Characters that
are not acceptable as file names are:

. — Period/Decimal Point

” — Quotation Marks
/ — Slash
\ — Back slash
[ ] — Brackets
: — Colon
| — Pipe
> — Greater Than
< — Less Than
+ — Plus sign
= — Equal Sign
; — Semicolon
, — Comma

And: All ASCII characters with a value lower

than the value of the space character (32 deci-

mal).

CAUTIO N

The INT command immediately formats
the disk loaded in the 360 floppy drive.

Any data on the disk will be destroyed.

Use this command carefully.

Table 5-8. Disk Functions Commands (1 of 2)

360 GPIB

Command

DEC(filename) Delete calibration and front panel setup file from

disk
DED(filename) Delete tabular printout data file from disk String up to 8 characters long for file name
DEN(filename) Delete trace memory file from disk String up to 8 characters long for file name
INT Initialize (format) disk in drive as a data-only disk N/A
LKT Load calibration kit information from disk N/A
RCK(filename) Recall active channel’s trace memory from disk file String up to 8 characters long for file name
RLD(filename) Recall calibration data and front panel setup

information from disk file
RTB(filename) Recall tabular data file from disk for output to printer String up to 8 characters long for file name

Description Values

Spaces are ac ce ptable be fore and after the
characters of a command, value or termi­nator. They are not acceptable between
the characters of these program items.

String up to 8 characters long for file name

String up to 8 characters long for file name

NOTE

5-14 360 GPIB PM

V ADVANCED GPIB PROGRAMMING DISK FUNCTION COMMANDS

Table 5-8. Disk Functions Commands (2 of 2)

360 GPIB

Command

SDK(filename) Store active channel’s trace memory to disk file String up to 8 characters long for file name
STO(filename) Store calibration data and front panel setup

information to disk file

TDD(filename) Store tabular printout data to ASCII disk file String up to 8 characters long for file name

! EXAMPLE 1 - SAVE CAL AND FRONT
! PANEL SETUP TO DISK
Q$ = CHR$(34) ! DOUBLE QUOTE SYMBOL(“)
C$ = “12_TERM” ! FILE NAME FOR CAL DATA
! STORE TO DISK FILE “12_TERM.CAL”
OUTPUT 706;"STO"&Q$&C$&Q$
! EXAMPLE 2 - SAVE TABULAR DATA
! TO DISK FILE
Q$ = CHR$(34) ! DOUBLE QUOTE SYMBOL(“)
T$ = “S21_THRU” ! FILE NAME FOR TAB DATA
! STORE TO DISK FILE “S21_THRU.DAT”
OUTPUT 706;"TDD"&Q$&T$&Q$
! EXAMPLE 3 - SAVE TRACE MEMORY
! TO DISK, RECALL IT ON A DIFFERENT
! CHANNEL AND THEN DELETE FILE
OUTPUT 706;"CH1 D13 S11 CH3 S21 FHI WFS"
OUTPUT 706;"CH1 STD" ! STORE TRACE TO MEMORY
Q$ = CHR$(34) ! DOUBLE QUOTE SYMBOL(“)
N$ = “S11TRACE” ! FILE NAME FOR TRACE DATA
! STORE TO DISK FILE “S11TRACE.NRM”
OUTPUT 706;"SDK"&Q$&N$&Q$
! RECALL SAME DATA ON CHANNEL 3
OUTPUT 706;"CH3 RCK"&Q$&N$&Q$
! DELETE THE TRACE MEMORY FILE
OUTPUT 706;"DEN"&Q$&N$&Q$

Description Values

String up to 8 characters long for file name

Figure 5-4. Disk Function Commands Example

360 GPIB PM 5-15

SRQ STATUS BYTE STRUCTURE AND COMM ANDS V ADVANCED GPIB PROGRAMMING

5-6 SRQ STATUS BYTE STRUCTURE

AND COMMANDS

The status of the 360 is defined by primary and
secondary status bytes. The structure and contents
of these status bytes are described in the following
paragraphs.

5-6.1 Primar y St atu s By te

The bit structure o f the primary status byte is show n
in Table 5-9. The function of each bit is described
below. All bits of the primary status byte are res et
whenever a CSB command is received.

• Cal. Sweep Complete. This bit is set when a
calibration sw eep is c ompleted after the TCD com­mand has been received.

• Sweep Complete In Hold. This bit is set when
a full sweep is completed in hold after the TRS
command has been received.

• Syntax Error. This bit is set is set when a syntax
error occurs

• Parameter Out Of Range. This bit is set when
data values are out of the allowable range or the
data was found to be invalid.

• Action Not Possi bl e. Th is bit is set when a com-
mand can not execute in the current instrument
state.

• 2nd Byte Has Status. This bit is set when a
condition represented by a set bit in the Secon­dary Status Byte is true.

• SRQ. The Service Request bit is set during the
serial poll response when the 360 is requesting
service.

• Ready for Measurement. This bit is cleared at
the start of both the GPIB measurement trigger
command (TIB) and by the data collection com­mands (CRD, CCD, CFD). The bit is set after a
point has been measured subsequent to a GET in
the GPIB measurement trigger mode when the
instrument is ready for data collection.

• Self Test Failed. This bit is set true if any por-
tion of the self test fails.

• Hardware Error. This bit is set when there is a
problem with the system hardware.

• Key Pressed. This bit is set when a key on the
front panel is pressed.

Power On. Th is bi t is set when the sy stem is firs t

•

powered on.

Table 5-11 lists the status byte commands. These
commands are used to:

• Output the status of the 360 to t he external com­puter.

• Input service request enable masks.

Clear the primary and secondary status bytes.

•

In order for the 360 to generate a service requ est for
a particular c on dition , both th e con dition bit an d the
SRQ bit in the Primary Status Byte Mask must be
enabled. The binary valu e of eac h bit in the byte sent
will be:

Bit Value = 1 – Status Condition Enabled.
When the 360 requests service, the serial poll re-

sponse byte will show only one enabled bit set. The
controller can then always tell which enabled condi­tion generated the Service Request (SRQ). This also
implies that the primary status byte and the serial

Tab le 5-9. Primary Status Byte Bit Structure

Bit Number

765 4 3 2 1 0

Ready

for

Meas.

SRQ 2nd

Byte

Has

Status

Action

Not
Pos­sible

Out of

Range

Syntax

Error

Com-

plete

in

Hold

Sweep

Com-

plete

5-6.2 Secondary Status Byte

Table 5-10. Secondary Status Byte Bit Structure

The bit structure of the Secondary Status Byte is
shown in Table 5-10. The function of each bit is
described below. All bits of the sec ondar y status byte

7 6 543 2 1 0

Bit Number

are reset whenever a CSB command is received.

• Disk Error. This bit is set when a disk error

Power OnKey

Pressed

X* X X Hardware

Error

Self

Test F ail

Disk

Error

occurs.

5-16 360 GPIB PM

V ADVANCED GPIB PROGRAMMING SRQ STATUS BYTE STRUCTURE AND COMMANDS

poll response byte will not necessarily be equal. Any
true bits for conditions not enabled will show up
the serial poll response byte. Figure 5-5 shows
listing of an example program that performs
byte-enable mask setup for the primary status
and service request handling operations.

Table 5-11. Status Byte Commands

360 GPIB

Command

CSB Clear primary and secondary status bytes N/A

<
<

byte
byte

>
>

IEM
IPM

OEB Output extended (secondary) status byte One binary byte
OPB Outp ut pri mar y sta tus by te One bina ry by te
SQ0 Disable service requests N/A
SQ1 Enable any unmarked service requests N/A

Input extended (secondary) status mask One binary byte
Input prim ary statu s mask One bina ry by te

in

a

status-

byte

Data transfers for the OPB, OEB, IPM
and IEM commands involve a single
binary data byte. The c ondition mask byte
for the IPM and IEM commands must
immediately follow the command.

Description Values

NOTE

! SET UP SERVICE REQUEST SUBROUTINE ADDRESS
ON INTR 7 GOSUB 1000
! ENABLE SRQ CONDITION AS AN INTERRUPT
ENABLE INTR 7;8
REMOTE 706
! ENABLE SRQ, SYNTAX, PARAM,
! OUT OF RANGE AND ACTION
! NOT POSSIBLE ERRORS = BITS
! 2,3,4 & 6
! MASK = 4+8+16+64 = 92
OUTPUT 706 USING “#,AAA,B”;"IPM",92
1000 ! SRQ SERVICE ROUTINE
1010 STATUS 7,1;A ! READ INTERRUPT CAUSE REGISTER
1020 R=SPOLL(706) ! POLL THE 360
1030 IF BIT(R,2) 1 THEN GOTO 1050
1040 DISP “SYNTAX ERROR”
1050 IF BIT(R,3) 1 THEN GOTO 1070
1060 DISP “PARAMETER OUT OF RANGE”
1070 IF BIT(R,4) 1 THEN GOTO 1090
1080 DISP “ACTION NOT POSSIBLE”
1090 ! READ THE PRIMARY STATUS BYTE
1100 OUTPUT 706;"OPB"
1110 ENTER 706 USING “#,B”;B
1120 DISP “PRIMARY STATUS = ”,B
1130 ! RE-ENABLE INTERRUPT AND RETURN
1140 ENABLE INTR 7;8 @ RETURN

Figure 5-5. Example of Status-Byte-Enable-Mask Setup and Service Request Handling

360 GPIB PM 5-17

TIME DOMAIN COMMANDS V ADVANCED GPIB PROGRAMMING

5-7 TIME DOM AIN COMM ANDS

The time domain commands for the 360 VNA are
listed below in Table 5-12. Option 2A (High-Speed
Time Domain [Distanc e] Software o ption) adds these

The time domain commands are used to:

1. S pecify the domain of a channel.

2. S et up operating modes and parameters for
the selected processing type of the channel.

commands to the 360 VNA software.

Table 5-12. Time Domain Commands (1 of 2)

360 GPIB

Command

DBP Select distance bandpass mode for active

channel

DCA Select automatic D.C. term calculation for

lowpass
DCO Select open for D.C. term for lowpass N/A N/A
DCS Select short for D.C. term for lowpass N/A N/A

Enter value for D.C. term for lowpass

DCV (value)
DCZ Select line impedance for D.C. term for

DLP Select distance lowpass mode for active

*

lowpass

channel

Description Values Terminators

N/A N/A

N/A N/A

-1000 MΩ to 1000 MΩ
N/A N/A

N/A N/A

XX1, XX3, XM3

DPI Select distance phasor impulse mode for

active channel

FGT Select frequency with time gate for active

FQD Select frequency domain for active channel N/A N/A
GCT (value) Set gate center value

GDS Display gate symbols on active channel N/A N/A
GLS Select low sidelobe gate shape N/A N/A
GMS Select minimum sidelobe gate shape N/A N/A
GNM Select nominal gate shape N/A N/A
GOF Turn off gating on active channel N/A N/A
GON Turn on gating on active channel N/A N/A
GRT Select rectangular gate shape N/A N/A
GSN (value) Set gate span value

GSP (value) Set gate stop value –999.9999 to +999.9999 PSC, NSC, USC,
GST (value) Set gate start value –999.9999 to +999.9999 PSC, NSC, USC,

channel

0.0000 to 999.999 µs

0.0000 to 999.999 m

0.0000 to 999.999 µs

0.0000 to 999.999 m

N/A N/A

N/A N/A

PSC, NSC, USC,

MMT, CMT, MTR

PSC, NSC, USC,

MMT, CMT, MTR

∗ Certain time doma in codes can only be used with particular processing types or instrument states. For example, “DCV 25 XX1" sets the

d.c. term for low pass to 25 ohms. The 360 can only execute this comma nd string if the active channel is in the time domain low pass
mode (TLP or DLP) or if a valid lowp ass set of frequencie s exist for freque ncy domain (FQD) or freq uency gated by time (FGT).

5-18 360 GPIB PM

V ADVANCED GPIB PROGRAMMING TIME DOMAIN COMMANDS

Table 5-12. Time Domain Commands (2 of 2)

360 GPIB

Command

LPI Select lowpass impulse response N/A N/A
LPS Select lowpass s tep response N/A N/A
MRR Restore original marker range N/A N/A
TBP Select time bandpass mode for active

channel
TLP Select time lowpass mode for active channel N/A N/A
TPI Select time phasor impulse mode for active

channel
WLS Select low sidelobe window shape N/A N/A
WMS Select minimum sidelobe window shape N/A N/A
WNM Select nominal window shape N/A N/A
WRT Select rectangular window shape N/A N/A
ZCT (value) Set zoom range center value

ZSN (value) Set zoom range span value

Description Values Terminators

N/A N/A

N/A N/A

–999.999 to 999.999 µs

–999.999 to 999.999 m

0 to 999.999 µs

0 to 999.999 m

PSC, NSC, USC
MMT, CMT, MTR

PSC, NSC, USC
MMT, CMT, MTR

ZSP (value) Set zoom range stop value

ZST (value) Set zoom range stop value

–999.999 to 999.999 µs

–999.999 to 999.999 m

–999.999 to 999.999 µs

–999.999 to 999.999 m

PSC, NSC, USC
MMT, CMT, MTR

PSC, NSC, USC
MMT, CMT, MTR

360 GPIB PM 5-19

MULTIPLE SOURCE CONT RO L COMM ANDS V ADVANCED GPIB PROGRAMM ING

5-8 MULTIPLE SOURCE CONTROL

COMMANDS

Table 5-13 lists the multiple source control com­mands. These commands are used to define up to
five different “multiple source control bands”. In
each, the device under test (DUT), source 1, source
2, and receiver frequency ranges may be different.
The DUT frequency range is entered using any of
the frequency entry commands. The MSD command
puts the 360 in the DEFINE mode, which allows
entry of arbitrary frequencies for the DUT. Band
equations for sou rce 1, sou rce 2, an d th e rec eiv er ar e
then set up using the ED1, ED2, EDR, etc, com­mands. The band equations used are shown below.
In these equations, “F” is the DUT frequency range.

For swept operation:

F = (m ult ipl ier/ di viso r) x (F + offset),

or, for CW operation: .

F = (m ult ipl ier/ di viso r) x (offset).

For a frequency band to be saved, the band equa­tions must produce frequencies within the operating
range of the respective system component.

Figure 5-6 shows an example program using
multiple source control commands. This program is
for a fixed LO, swept IF mixer measurement. The
frequency values used are:

DUT range = 2 – 6 GHz
Source 1 = 2 – 6 GHz = (1/1) X (F + 0)
Source 2 = 500 MHz CW = (1/1) X (500 MHz)
Receiver = 1.5 – 5.5 GHz = (1/1) X (F – 500 MHz)

10 ! Multiple Source Control Example
20 OUTPUT 706; “MSD SRT 2 GHZ STP 6 GHZ”
30 OUTPUT 706; “BD1 BSP 6 GHZ”
40 OUTPUT 706; “ED1 ESW EML 1 XX1"
50 OUTPUT 706; “EDV 1 XX1 EOS 0 GHZ”
60 OUTPUT 706; “ED2 ECW EOS 500 MHZ”
70 OUTPUT 706; “EDR ESW EML 1 XX1"
80 OUTPUT 706; “EDV 1 XX1 EOS -500 MHZ”
90 OUTPUT 706; “SVB MS1"

100 END

Figure 5-6. Multiple Source Control Example

Table 5-13. Multiple Source Control Commands

360 GPIB

Command

BD1 - BD5 Select multiple source control band 1-5 (Limited to current DUT range) N/A
BSP (value) Ent er band stop f requen cy for multiple so urc e cont rol Start sweep frequency to stop

BST (value) Enter band 1 startup frequency for multiple source

control
CLB Clear all multiple source control band definitions N/A N/A
ECW Multiple source control equation in CW mode N/A N/A
ED1 Edit source 1 multiple source control equation N/A N/A
ED2 Edit source 2 multiple source control equation N/A N/A
EDR Edit receiver multiple source control equation N/A N/A
EDV (value) Set multiple source control equation divisor –199 to –1, 1 to 199 XX1, XX3, XM3
EML (value) Set multiple source control equation multiplier –199 to 199 XX1, XX3, XM3
EOS (value) Set multiple source control equation offset frequency –999.9999 to 999.9999 GHZ, MHZ, KHZ
ESW Multiple source control equation in sweep mode N/A N/A
MS0 Multiple source control off N/A N/A

Description Values Terminators

GHZ, MHZ, KHZ

sweep frequency

Start sweep frequency to stop

sweep frequency

GHZ, MHZ, KHZ

MS1 Multiple source control on N/A N/A
MSD Multiple source control define model N/A N/A
SVB Save multiple source control band definition N/A N/A

5-20 360 GPIB PM

V ADVANCED GPIB PROGRAMMING SWEEP CONTROL COMMANDS

5-9 SWEEP CONTROL COMMANDS

Table 5-14 lists the 360 GPIB commands that allow
control of sweep triggering. The TIN, TEX and TIB
commands select the measurement trigger source,
as follows:

• Command TIN selects internal triggering;

• Command TEX selects triggering via the rear-

panel input connector;
Command TIB selects triggering via the group

•

execute trigger, GET, which is an IEEE-488 inter­face function message that is issued by the exter­nal computer.

NOTE

The use of the TIB c ommand turns- off
the normal DEF—END response to
the GET interface function message;
refer to paragraph 5-4.

The HC0 command should be used to disable the
internal I.F. calibration when external or GPIB trig­gering is used (so that triggers are not missed while

Table 5-14. Sweep Control Commands

360 GPIB

Command

HC0 Disable Internal I.F. Calibration
HC1 Enable and Tr igger Internal I . F. Calibration
TEX Select External Measurement Triggering

Description

the instrument performs an I.F. calibration). The
HC1 command can then be used to enable and
initiate an immediate I.F. calibration, when desired.

5-10 REAR PANEL OUTPUT CONTROL

COMMANDS

Table 5-15 lists the commands for controlling the
rear-panel voltage output of the 360 VNA. The RV1
command enables the output and comman d RV0 dis­ables it. The orientation of the output can be set to
either horizontal (RVH), vertical (RVV), or lock di­rection (RVL).

In the horizontal mode, the voltage output is a
digital ramp starting at the voltage start value set
by command VST and ending at the voltage stop
value set by command VSP. The start value
corresponds to the first point of the sweep and the
stop value corresponds to last point of the sweep. In
the vertical mode, the output voltage is a measure
of the instantaneous data point value. The output
voltage is related to the scaling of the graph for
channe l 1. Th e refe re nce line c orr espon ds to the zer o
volt value and each gratic le line is equal to a ±1 volt
value span. The values set by the VST and VSP
commands have no effect in the vertical mode.

In the lock direction mode, the start voltage value is
output for forward sweeps (lock to Ra). The stop
voltage value is output for reverse sweeps (lock
to Rb).

TIB Select Measurement Triggering Via

Group Execute Trigger

TIN Select Internal Measurement Triggering

The RP0 command is used to set an intermediate
voltage value that is output at the rear panel con­nector. This command can be executed only if the
normal rear panel output voltage is disabled.

Table 5-15. Rear Panel Output Control Commands

360 GPIB

Command

RPO (value) Set value for direct rear panel voltage –10 to 9.96 volts VLT
RV0 Disable rear panel output voltage N/A N/A
RV1 Enable rear panel output voltage N/A N/A
RVH Select horizontal rear output voltage mode N/A N/A
RVL Select lock direction output voltage mode N/A N/A
RVV Select verticle rear output voltage mode N/A N/A
VSP (value) Set stop value for rear panel output voltage –10 to 9.96 volts VLT
VST (value) Set start value for rear panel output voltage –10 to 9.96 volts VLT

Description Values Terminators

360 GPIB PM 5-21

SCREEN DRAW AND RECEIVER MODE
COMMAND CODES V ADVANCED GPIB PROGRAMMING

5-11 SCREEN DRAW COMMANDS

The commands listed in Table 5-16 control the
screen drawn functions of the 360 VNA in the GPIB
mode of operation.

Table 5-16. Screen Draw Commands

360 GPIB

Command

CWP (value) Enter numbe r of

DD0 Turn off data

DD1 Turn on data

Description Values

points drawn in
CW

drawing

drawing

1 – 501 XX1

N/A N/A

N/A N/A

Termin-

ators

5-12 R ECE IVER MOD E COMM ANDS

The commands listed in Table 5-17 control the 360
VNA receiver mode functions in the GPIB mode of
operation.

Table 5-17. Receiver Mode Control Commands

360 GPIB

Command

SDR Select standard receiver mode
SL0 Selec t source lock mode with GPIB sour ce

control off

SL1 Selec t source lock mode with GPIB sour ce

control on

ST0 Select set on mode with GPIB source

control off

ST1 Select set on mode with GPIB source

control on

TK0 Select tracking mode with GBIB source

control off

TK1 Select tracking mode with GBIB source

control on

Description

5-22 360 GPIB PM