on Feb 10, 2010There are two methods of using the external clock reference to synchronize the outputs of multiple function/arbitrary waveform generators. Each function/arbitrary waveform generator requires an external clock reference. The external clock reference is standard on the 33250A, and is option 001 on the 33210A and 33220A. Option 001 is available as a retrofit.
The first method has the function/arbitrary waveform generator output a continuous waveform. You can get a more precise phase relationship using this method and is easier to use when making changes to the phase relationship between the generators.
The second method uses infinite burst mode. It is a bit more complex to set up, but once it is set up it is easier to use when making changes to the waveform shape or frequency. While it is not as accurate as the first method, the additional trigger error is not a significant factor for many applications.
CONTINUOUS MODE
On the master unit, connect a BNC cable to the 10 MHZ OUT. On the slave unit, connect the clock reference cable to the 10 MHZ IN.
Power on both units and configure waveform (shape, frequency, amplitude, offset, etc). Enable the output on both units by pressing OUTPUT.
Align the outputs of both units:
Connect outputs to an oscilloscope or counter and find the current phase relationship.
On the SLAVE UNIT:
- Press the UTILITY key on the front panel and select OUTPUT SETUP on the softkeys.
- Select the softkey for ADJUST PHASE.
- Using the **** (recommended), adjust the phase until both outputs are aligned at 0 phase.
- Press the SET 0 PHASE softkey.
- Adjust the PHASE using the **** or keypad to the desired phase relationship (eg 180.000 degrees).
Remove output connections from oscilloscope/counter and reapply to application.
To make a change to waveshape or frequency, make the change and repeat the alignment procedure on both units. To make a change to the phase relationship, simply re-adjust the phase as desired (eg 90.000 degrees, 180.010 degrees).
INFINITE BURST MODE
On the master unit, connect BNC cables to the 10 MHZ OUT and the EXT TRIG. On the slave unit, connect the clock reference cable to the 10 MHZ IN and the trigger cable to the EXT TRIG.
Power on both units and configure waveform (shape, frequency, amplitude, offset, etc).
Configure BURST on both units. Press the BURST key from the front panel. Starting from the left, use the softkeys to toggle between parameters to the following settings:
Select N CYCLE
Select INFINITE
START PHASE may be set. Set it to the phase you wish the waveform to have on each unit. For example, if two units should have a phase relationship of 180 degrees, set the master to 0 degrees, and the slave to 180 degrees. You can also set -90 degrees and +90 degrees if you wish.
BLANK KEY
BLANK KEY
TRIGGER SETUP: This will open a new menu. From left to right, again use the softkeys to toggle between parameters:
ON THE MASTER UNIT:
- SOURCE: Set to MANUAL (front panel trigger key will light).
- BLANK KEY
- TRIG OUT: Select a slope, either positive or negative.
- BLANK KEY
- BLANK KEY
- DONE: Press this key to finish
ON THE SLAVE UNIT:
- SOURCE: Set to EXT
- SLOPE: Set to match slope of the master TRIG OUT setting
- BLANK KEY
- BLANK KEY
- BLANK KEY
- DONE: Press this key to finish
Turn on the OUTPUT if not already done. Press the TRIGGER key on the master unit to start the output on both units.
To make a change (frequency, waveshape, phase, etc) press the TRIGGER key on both units to stop the infinite burst. Make the changes, then press the TRIGGER key on the master unit to start the output on both units.
http://www.home.agilent.com/agilent/faq ... id=1625192
The first method has the function/arbitrary waveform generator output a continuous waveform. You can get a more precise phase relationship using this method and is easier to use when making changes to the phase relationship between the generators.
The second method uses infinite burst mode. It is a bit more complex to set up, but once it is set up it is easier to use when making changes to the waveform shape or frequency. While it is not as accurate as the first method, the additional trigger error is not a significant factor for many applications.
CONTINUOUS MODE
On the master unit, connect a BNC cable to the 10 MHZ OUT. On the slave unit, connect the clock reference cable to the 10 MHZ IN.
Power on both units and configure waveform (shape, frequency, amplitude, offset, etc). Enable the output on both units by pressing OUTPUT.
Align the outputs of both units:
Connect outputs to an oscilloscope or counter and find the current phase relationship.
On the SLAVE UNIT:
- Press the UTILITY key on the front panel and select OUTPUT SETUP on the softkeys.
- Select the softkey for ADJUST PHASE.
- Using the **** (recommended), adjust the phase until both outputs are aligned at 0 phase.
- Press the SET 0 PHASE softkey.
- Adjust the PHASE using the **** or keypad to the desired phase relationship (eg 180.000 degrees).
Remove output connections from oscilloscope/counter and reapply to application.
To make a change to waveshape or frequency, make the change and repeat the alignment procedure on both units. To make a change to the phase relationship, simply re-adjust the phase as desired (eg 90.000 degrees, 180.010 degrees).
INFINITE BURST MODE
On the master unit, connect BNC cables to the 10 MHZ OUT and the EXT TRIG. On the slave unit, connect the clock reference cable to the 10 MHZ IN and the trigger cable to the EXT TRIG.
Power on both units and configure waveform (shape, frequency, amplitude, offset, etc).
Configure BURST on both units. Press the BURST key from the front panel. Starting from the left, use the softkeys to toggle between parameters to the following settings:
Select N CYCLE
Select INFINITE
START PHASE may be set. Set it to the phase you wish the waveform to have on each unit. For example, if two units should have a phase relationship of 180 degrees, set the master to 0 degrees, and the slave to 180 degrees. You can also set -90 degrees and +90 degrees if you wish.
BLANK KEY
BLANK KEY
TRIGGER SETUP: This will open a new menu. From left to right, again use the softkeys to toggle between parameters:
ON THE MASTER UNIT:
- SOURCE: Set to MANUAL (front panel trigger key will light).
- BLANK KEY
- TRIG OUT: Select a slope, either positive or negative.
- BLANK KEY
- BLANK KEY
- DONE: Press this key to finish
ON THE SLAVE UNIT:
- SOURCE: Set to EXT
- SLOPE: Set to match slope of the master TRIG OUT setting
- BLANK KEY
- BLANK KEY
- BLANK KEY
- DONE: Press this key to finish
Turn on the OUTPUT if not already done. Press the TRIGGER key on the master unit to start the output on both units.
To make a change (frequency, waveshape, phase, etc) press the TRIGGER key on both units to stop the infinite burst. Make the changes, then press the TRIGGER key on the master unit to start the output on both units.
http://www.home.agilent.com/agilent/faq ... id=1625192
I connected a BNC cable from 10MHz ref out of 33120A to 10MHz ref in of 33250A. I kept the same frequency (200kHz) and signal shape (square wave) on both and with the help of Oscilloscope, I reduced the phase between the 2 signals to zero. Then I changed the output signal to arb signal on 33250A which has 64000 data points with repetition rate of 3.125kHz and peak to peak amplitude of 100mV.
Now, I have a couple of questions:
1. After changing to arb wave in 33250A, I couldn't lock the 2 signals on oscilloscope. I triggered the arb signal on the scope, but the square wave signal from 33120A was walking around still. Why is that? How can I avoid the walking of square wave signal if possible?
2. In order to further understand, I reverted back to square wave on 33250A and frequency back to 200kHz, I was surprised to see the phase between the 2 signals on Oscilloscope is not zero anymore. (I didn't remove the BNC cable or turn off any of the systems in the middle of this trial). Why does this happen?