Products > Test Equipment
Rigol DG800 (long) list of problems and the sad death of a FPGA
_Wim_:
The relay will be the same problem on the MSO-X 3034A. The decay in between the bursts comes from the fact you were using the 1M input on the MSO-X 3034A, and I was using a 50ohm adaptor on the DS1054Z. With the 50 ohm input the decay time constant was very small and no decay between burst is visible.
TurboTom:
IMO, the proper way of switching on an AWG would unfortunately require additional hardware. It would be as follows:
The AWG has got a high-impedance (>1GOhm) input permanently wired to the output to measure the open-circuit input voltage of the device attached to the AWG.
1 - The output relay is open and the AWG measures the open-circuit output voltage.
2 - The AWG adjusts its output voltage to the measured voltage while the output relay is still open.
2 - The AWG closes the output relay and waits for the relay bounce time to pass. Since there is no voltage differential at the output, no current will be flowing and no bounce spikes will be present at the output
3 - The AWG starts outputting the preconfigured waveform.
AFAIK, none of the budget AWGs has got the mentioned option to read-back the voltage at the (disconnected) output. I think I've read about some TEK AWGs that utilize some kind of digital feedback so there this switch-on scheme should be possible. A "cheap" solution to work around pos. 1 of the list above would be to add an (optional) menu item to the parameter list of "Initial Output Level" so the user can at least predefine something that suits the application best.
thm_w:
I will update here once I receive Rigols response.
But I don't understand this:
--- Quote ---Second the phase alignment is broken.
Lets set the output frequency to 0.8 MHz and angle to 0 deg. Then lets change the frequency form 0.8 MHz to 1.3MHz in 0.1 MHz steps, pressing the align button every time, here are the results:
f[MHz] 0.8 0.9 1.0 1.1 1.2 1.3
Angle[°] 10 12.2 15.8 1.7 4.6 -0.4
--- End quote ---
I tried having channel one and channel two outputting a square wave or pulse of the same frequency, duty cycle can be slightly different. At no point did I see the phase angle (CH1->CH2) exceed the noise of the scope (<1deg) after Align.
So I must be missing something, OP can you provide a few more details?
FW version 00.01.08.00.01
TurboTom:
Try it with a sine and a square wave.
MrFox:
I tested a 0v to 3.3v 1Mhz on a 1022Z (unlocked to 1062Z) with latest firmware, and it only shows the expected relay bounce, the offset is otherwise instantaneous.
Could there some hardware revisions involved here?
I do wish there was a configurable weak pull up/down while the relay bounce and a delay before it starts. These things are not exactly full featured for using them as digital outputs.
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