HP 33120A User manual

HP 33120A / Option 001
Phase-Lock Assembly
User’s Guide
Part Number 33120-90020
August 1994
For Safety information and Warranties, see the page behind
the Index.
©Copyright Hewlett-Packard Company 1994
All Rights Reserved.

Contents
Chapter 1 Quick Start
The Rear Panel at a Glance 3
The Front-Panel Menu at a Glance 4
To phase lock to an external clock signal 5
To phase lock multiple function generators 7
To set a zero phase reference 9
To phase lock using the triggered burst mode 10
To generate a phase unlock error 14
Chapter 2 Remote Interface Operation
SCPI Command Summary 17
Phase-Lock Commands 18
Simplified Programming Overview 20
The SCPI Status Registers 23
Status Reporting Commands 26
Phase-Lock Error Messages 27
Chapter 3 Specifications 29
Chapter 4 Replaceable Parts and Schematics
To Order Replaceable Parts 32
Backdating and Parts Changes 32
Replaceable Parts Lists 33
Manufacturer’s List 35
Component Locator Diagram 36
Schematic Diagram 37
Index 39
Contents

1
Quick Start
1

Quick Start
This manual contains supplemental information for the HP 33120A
Phase-Lock assembly. Refer to the HP 33120A User’s Guide and
Service Guide for complete details on using the function generator.
The Phase-Lock assembly (Option 001) adds the following capabilities to
the HP 33120A Function Generator /Arbitrary Waveform Generator:
•External clock input and output connectors on the rear panel.
These connectors allow synchronization between multiple HP 33120As
or to an external 10 MHz clock signal.
•Phase offset control from the front panel or over the remote interface.
•Simultaneous hardware triggering of multiple HP 33120As.
Option 001 allows the HP 33120A to generate a trigger pulse from
the Ext Trig terminal which can be routed to other instruments in
a system.
•2 ppm timebase—10 times the frequency stability of the standard
HP 33120A.
If you have questions relating to the operation of the function generator,
call 1-800-452-4844 in the United States, or contact your nearest
Hewlett-Packard Sales Office.
2

The Rear Panel at a Glance
The Phase-Lock assembly adds the Ref Out and Ext Ref In terminals
to allow synchronization between multiple HP 33120As or to an
external 10 MHz clock signal.
1Internal 10 MHz reference output terminal
2External 10 MHz reference input terminal
3Chassis ground
4Power-line fuse-holder assembly
5Power-line voltage setting
6AM modulation input terminal
7External Trigger / FSK / Burst modulation
input terminal
8HP-IB (IEEE-488) interface connector
9 RS-232 interface connector
1
Chapter 1 Quick Start
The Rear Panel at a Glance
3

The Front-Panel Menu at a Glance
The Phase-Lock assembly adds the Phase Menu to the front-panel menu.
The menu is organized in a top-down tree structure with three levels.
G: PHASE MENU
1: ADJUST

2: SET ZERO

3: TRIG OUT

4: UNLOCK ERR
1: ADJUST
2: SET ZERO
3: TRIG OUT
4: UNLOCK ERR
Sets the phase offset of the output waveform to a value in degrees.
Nulls the phase offset to a zero reference for relative adjustments.
Enables or disables an external trigger from the
Ext Trig terminal.
Enables or disables error generation when phase-lock is lost.
Chapter 1 Quick Start
The Front-Panel Menu at a Glance
4

To phase lock to an external clock signal
The rear-panel Ext Ref In terminal allows you to synchronize one or
more function generators with an external 10 MHz signal. The following
steps show you how to configure a single instrument for synchronization
with an external signal.
1 Select the function and set the output frequency to 10 MHz.
You must select either sine or square wave since the other output
waveforms cannot be used up to 10 MHz.
10.000,000 MHz
To adjust the phase offset, you will use the front-panel menu as described
on the following page.
Freq
1
Chapter 1 Quick Start
To phase lock to an external clock signal
5

2 Turn on the menu.
A: MOD MENU
3 Move across to the PHASE MENU choice on this level.
G:PHASE MENU
4 Move down a level to the ADJUST command.
1: ADJUST
5 Move down a level and set the phase offset.
You can set the offset to any value between -360 degrees and +360 degrees.
The displayed phase is output “real time” unless you have selected the
arbitrary waveform function.
∧000.000 DEG
6 Turn off the menu.
The function generator beeps and displays a message. You are then
exited from the menu.
At this point, the function generator is phase-locked to the external clock
signal with the specified phase relationship. The two signals will
remain locked unless you change the function or output frequency.
∨
Enter
<
∨
Menu On/Off
Shift
Chapter 1 Quick Start
To phase lock to an external clock signal
6

To phase lock multiple function generators
The rear-panel Ref Out and Ext Ref In terminals allow you to
synchronize multiple function generators. The diagram below shows
how to make connections for the “real-time” phase-lock mode. In the
real-time mode, the phase offset relationship is random at first. You can
adjust the phase offset “real time” from the front panel. The following
steps show you how to synchronize two function generators at 10 kHz.
1 Set both instruments to the same output frequency.
You can select sine, square, ramp, or triangle waveforms for phase-lock
operation. You cannot perform real-time phase adjustments on arbitrary
waveforms.
10.000,000 KHz
To adjust the phase offset, you will use the front-panel menu as described
on the following page.
Freq
1
Chapter 1 Quick Start
To phase lock multiple function generators
7

2 Turn on the menu.
A: MOD MENU
3 Move across to the PHASE MENU choice on this level.
G:PHASE MENU
4 Move down a level to the ADJUST command.
1: ADJUST
5 Move down a level and set the phase offset.
You can set the offset to any value between -360 degrees and +360 degrees.
The displayed phase is output “real time” unless you have selected the
arbitrary waveform function.
∧000.000 DEG
6 Turn off the menu.
The function generator beeps and displays a message. You are then
exited from the menu.
At this point, the two function generators are phase-locked with the
specified phase relationship. The two signals will remain locked unless
you change the function or output frequency.
∨
Enter
Menu On/Off
Shift
<
∨
Chapter 1 Quick Start
To phase lock multiple function generators
8