Rigol MSO5000 : waveform generator, impedance, and amplitude ? - Page 1
Forum section: electronics / testgear

author: django
author_rank: Newbie
timestamp: February 23, 2025, 08:00:13 am
content: Hi, I own a Rigol MSO5074 I upgraded according to the method provided in this forum.I'm learning how to use it, and after the basic manipulations I tried the built-in signal generator. And I noticed it behaved in a strange way to me.So, according to the manual :QuoteA quick check on the scope's interface confirms that for every channel, the impedance menu cannot be clicked, it is greyed out.Once again, according to the manual, in the section dedicated to the waveform generator :QuoteBut, if I set a periodic signal (let's say, a sine wave) in GI interface and I give it a 1V amplitude, I would expect as everyone to see a 2V peak to peak signal on my screen.Though, that is not the case !!!I see a 1V pk to pk sine wave...Let's break down what I've thought about :According to the manual, selecting 50Ω on the generator's side would make him think it faces a voltage divider, hence if we set the amplitude of the signal to 1V with HighZ option, then we switch to 50Ω , the amplitude value displayed by the generator menu is now 500 mV. If we change again from 50Ω to High Z, the value doubles and gets back to 1V. Of course, according to the manual, nothing changes in the signal.If instead of the the Amplitude option (currently set to 1V, remember) I switch to High Level, I get 2 options : High Level & Low Level. And they are automatically set to +500mV and -500mV. That is to say that for the scope, a 1V amplitude is 1V peak to peak (-500mV to +500mV).That's not my definition of an amplitude.So to have (according to my definition) a signal with 1V amplitude, I would set manually high level = +1V and low level = -1V. It displays as expected. If I roll back to Amplitude instead of High Level, I get a 2V amplitude.I don't have a BNC--> BNC coax cable but I have probes that I compensated, my scope is calibrated, I tried x1 and x10 both on the probe's switches and in the menu...So what am I missing here ? ThanksEdit : here is a short video to illustrate what I mean, it will last for a couple of dayshttps://streamable.com/runa1j

author: Kean
author_rank: Unknown
timestamp: February 23, 2025, 08:59:27 am
content: Read the manual or datasheet and you will see them specify amplitude as Vpp. It is a pity they don't show this on the screen when you are setting the value, but using Vpp is pretty common on an AWG.Just think about the AWG use, because it isn't just for generating sine waves, or other bipolar signals. For example if you want a TTL square wave going from 0 to 5V, you would set low level to 0V and high level to 5V, or you could set amplitude to 5V and offset to 2.5V.

author: django
author_rank: Newbie
timestamp: February 23, 2025, 09:19:39 am
content: Wow, thanks, I was beginning to think I was crazyI haven't read the whole manual yet, but when I read that :QuoteI figured out that Amplitude had to be understood like "from ref (0) to Vmax", as it is according to its normal definition.Mystery solved

author: Kean
author_rank: Unknown
timestamp: February 24, 2025, 05:11:33 pm
content: Quote from: Kean on February 23, 2025, 08:59:27 amNote - I realized a while after posting the above that although the MSO5000 generators can output 5Vpp, they are actually limited to +/-2.5V in 1M impedance mode (+/-1.25V in 50Ω), so you can't actually generate a 5V TTL or even a 3.3V CMOS square wave.Someone else mentions getting it to generate a 0-3V square wave, but that doesn't work on mine.https://www.eevblog.com/forum/testgear/rigol-mso5000-arb-generator-dc-offsets/

author: rolfdegen
author_rank: Regular Contributor
timestamp: April 15, 2025, 04:35:01 pm
content: Hallo friends.. Please help. I lost my Passwort for my Rigol MSO5104. Lan setting is WebControl: admin and rigol. Bat i cant open web control: Passwort 401 - UnauthorizedThanks for your helpFrom my scope MSO5104