HP 33120A User manual
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
To set a zero phase reference
After selecting the desired phase relationship as described on the
previous pages, you can set a zero-phase point. The function generator
then assumes that its present phase is zero and you can adjust the
phase relative to this new “zero”.
1 Turn on the menu.
A: MOD MENU
2 Move across to the PHASE MENU choice on this level.
G:PHASE MENU
3 Move down a level and then across to the SET ZERO command.
2: SET ZERO
4Move down a level to set the zero phase reference.
The displayed message indicates that the phase reference will be set
to zero degrees (you must exit the menu to select the displayed value).
PHASE = 0
5 Save the phase reference and turn off the menu.
The function generator beeps and displays a message to show that the
change is now in effect. You are then exited from the menu.
∨
Enter
Menu On/Off
Shift
<
∨ >
1
Chapter 1 Quick Start
To set a zero phase reference
9
To phase lock using the triggered burst mode
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 “triggered burst” phase-lock mode.
In the triggered burst mode, you can synchronize phase-lock signals
using an external trigger from the rear-panel Ext Trig terminal.
The following steps show you how to synchronize two function
generators at 10 kHz in the triggered burst mode.
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
Freq
Chapter 1 Quick Start
To phase lock using the triggered burst mode
10
2 Enable the burst mode on both instruments.
Notice that the Burst annunciator turns on.
3 Use the menu to set the burst count on both instruments.
After you enable the burst mode, the “recall menu” key will
automatically take you to the BURST CNT command in the MOD MENU.
4: BURST CNT
4Move down to the parameter level and set the count to “INFINITE”.
Press the right or left arrow keys until the “CYC” units are flashing.
Then, press the down arrow key to display “INFINITE”.
INFINITE
5 Save the change and turn off the menu.
The function generator beeps and displays a message to show that the
change is now in effect. You are then exited from the menu.
ENTERED
Next, you will set up the starting phase of the burst as shown on
the next page.
Burst
Recall Menu
Shift
<
∨
Enter
Shift
1
Chapter 1 Quick Start
To phase lock using the triggered burst mode
11
6GototheBURST PHAS command in the MOD MENU.
6:BURST PHAS
7 Move down a level and set the burst phase.
You can set the starting phase of the burst to any value between
-360 degrees and +360 degrees. With the BURST PHAS command,
the phase adjustment is not “real time”; you must exit the menu
to output the specified starting phase.
∧000.000 DEG
8 Save the change and turn off the menu.
The function generator beeps and displays a message to show that the
change is now in effect. You are then exited from the menu.
ENTERED
Next, you will configure one of the function generators to source an
external trigger from its rear-panel Ext Trig terminal.
9 On one instrument, go to the TRIG OUT command in the PHASE
MENU.
3: TRIG OUT
10 Move down a level and enable the external trigger.
ENABLE
Menu On/Off
Shift
∨
Enter
∨
Menu On/Off
Shift
Chapter 1 Quick Start
To phase lock using the triggered burst mode
12
11 Save the change and turn off the menu.
The external trigger setting is stored in volatile memory; the external
trigger state is disabled when power has been off or after a remote-
interface reset.
ENTERED
12 Enable both instruments for phase-lock operation.
Press the Single trigger key on both function generators to enable
phase-lock operation. Next, change the output function both function
generators (e.g., change from square wave to sine wave and then back to
square wave). The Trig annunciator should be on to indicate that each
function generator is in the single trigger mode.
13 Issue a single trigger to initiate the triggered burst.
Press the Single trigger key on the function generator with TRIG OUT
enabled. The function generator triggers itself and also outputs a trigger
pulse from its rear-panel Ext Trig terminal.
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
Single
Single
1
Chapter 1 Quick Start
To phase lock using the triggered burst mode
13
To generate a phase unlock error
You can configure the function generator to generate an error condition
whenever phase lock is lost. The following steps show you how to enable
an unlock error.
1 Turn on the menu.
A: MOD MENU
2 Move across to the PHASE MENU choice on this level.
G:PHASE MENU
3 Move down a level and then across to the UNLOCK ERR command.
4:UNLOCK ERR
4Move down a level and enable the unlock error.
ENABLE
5 Save the change and turn off the menu.
The unlock error setting is stored in non-volatile memory, and does not
change when power has been off or after a remote-interface reset.
See also “The SCPI Status Registers” on page 23.
∨
Enter
Menu On/Off
Shift
<
∨ <
Chapter 1 Quick Start
To generate a phase unlock error
14
2
Remote Interface
Operation
2
Remote Interface Operation
This chapter gives an overview of the Phase-Lock commands available
to program the function generator over the remote interface. Refer to
chapter 4 in the HP 33120A User’s Guide for complete details on
configuring the function generator for remote interface operation.
•SCPI Command Summary, on page 17
•Phase-Lock Commands, on page 18
•Simplified Programming Overview, on page 20
•The SCPI Status Registers, on page 23
•Status Reporting Commands, on page 26
•Phase-Lock Error Messages, on page 27
16
SCPI Command Summary
This section summarizes the SCPI (Standard Commands for
Programmable Instruments) commands available to program the
Phase-Lock assembly over the remote interface. If you are a first-time
user of the SCPI language, refer to “An Introduction to the SCPI
Language,” starting on page 211 in the HP 33120A User’s Guide.
Throughout this manual, the following conventions are used for
SCPI command syntax.
•Square brackets ( [ ] ) indicate optional keywords or parameters.
•Braces ( { } ) enclose parameters within a command string.
•Triangle brackets ( < > ) indicate that you must substitute a value
for the enclosed parameter.
•A vertical bar ( |) separates multiple parameter choices.
Phase-Lock Commands (Option 001)
(see page 18 and 19 for more information)
PHASe:ADJust {<radians>|MINimum|MAXimum}
PHASe:ADJust?
PHASe:REFerence
PHASe:UNLock:ERRor:STATe {OFF|ON}
PHASe:UNLock:ERRor:STATe?
OUTPut:TRIGger:IMMediate
OUTPut:TRIGger:STATe {OFF|ON}
OUTPut:TRIGger:STATe?
*OPT?
2
Chapter 2 Remote Interface Operation
SCPI Command Summary
17
Phase-Lock Commands
This section describes the SCPI (Standard Commands for Programmable
Instruments) commands available to program the Phase-Lock assembly.
Refer to chapter 4 in the HP 33120A User’s Guide for details on the
complete set of commands for the function generator.
PHASe:ADJust {<radians>|MINimum|MAXimum}
Adjust the phase offset of the output waveform in radians. Select from
-2πradians to +2πradians. The default is 0 radians. MIN = -2πradians.
MAX = +2πradians. [ Stored in volatile memory ]
•To specify phase in degrees instead of radians, specify “DEG” following
the phase value as shown below:
"PHAS:ADJ -90 DEG"
•For sine, square, triangle, and ramp waveforms, 0 radians is the point
at which the waveform crosses zero volts (or the dc offset value), in a
positive-going direction. For arbitrary waveforms, 0 radians is the
first point downloaded to memory.
•This phase adjustment for phase-lock is independent of the burst
phase as set by the BM:PHAS command. See “Burst Modulation” in the
HP 33120A User’s Guide for more information on burst phase.
PHASe:ADJust?
Query the phase offset setting. Returns a value in radians.
PHASe:REFerence
Immediately set the zero-phase reference point. This command does not
change the phase offset as set with the PHAS:ADJ command, it only
changes the phase reference. This command has no query form.
Chapter 2 Remote Interface Operation
Phase-Lock Commands
18
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