EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: David14 on March 17, 2014, 09:59:38 am
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Hi All,
I very recently purchased the Agilent MSOX2012A scope.
My main intended use is to be able to visualize in real time and debug systems that include analog to digital converter (ADC, A2D...) .
I need the ability to see at least one analog signal and at least one SPI bus simultaneously.
To my surprise the digital channels cannot be decoded at all. Not even one serial protocol is supported, this is very strange because any low level cheap micro-controller based logic analyzer can easily decode most common serial signals like SPI, I2C and UART. I tried Agilent's "Serial Decode" option but it is useless to me, it only decodes analog channels and I only have two analog channels and I need at least one of them for my analog signal. I know that Agilent's real time serial decoder is implemented in the ASIC and on my model is only available on the analog channels, but the decoding of serial digital protocols is very simple and has low computational requirements. Most modern micro-controllers implement this feature.
Couldn't Agilent implement some sort of software-based, even "offline" (not in run mode) serial decoding? That would save me the trouble switching to another scope.
A modern Logic Analyzer can decode serial data. I expect Agilent not claim that their product has a logic analyzer if it is useless for most modern implementations. That "logic analyzer" cannot even decode a classic 8bit bus because you need at least two more digital channels for the clock and enable/CS signals.
I know that Agilent's 3000 series scopes can probably do what I need but they are much more expensive.
I checked other MSO manufacturers:
Tektronix: MSO2012B + DPO2EMBD Has it (about the same price)
Rigol: MSO4012 Has it (about the same price)
Hameg: HMO1022 + HO3508 + HOO10 Has it (about the same price)
Siglent MSO / SDS2102 + function gen. + serial decode Has it (somewhat cheaper)
Lecroy: MS-250 + serial decode option Has it (more expensive but better)
So, actually only Agilent wont trigger and decode on digital serial channels on their "MSO"
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I very recently purchased the Agilent MSOX2012A scope.
My main intended use is to be able to visualize in real time and debug systems that include analog to digital converter (ADC, A2D...) .
I need the ability to see at least one analog signal and at least one SPI bus simultaneously.
This is not the scope you're looking for.
To my surprise the digital channels cannot be decoded at all. Not even one serial protocol is supported,
Yes, that's an unfortunate limitation.
I know that Agilent's real time serial decoder is implemented in the ASIC and on my model is only available on the analog channels, but the decoding of serial digital protocols is very simple...
Couldn't Agilent implement some sort of software-based, even "offline" (not in run mode) serial decoding? That would save me the trouble switching to another scope.
Could they? Perhaps. Will they? No chance. Time to deal with the reality of the situation. Since you purchased "recently", you may still have an opportunity to rectify your mistake.
Have you considered a 4-channel version of the X2000? I don't know effective that would be with 3 channels for SPI, so you'd have one left for the analog signal. Otherwise, you already have a list of other scopes that will do what you need.
I checked other MSO manufacturers... So, actually only Agilent wont trigger and decode on digital serial channels on their "MSO"
Yep. Sorry. :( No scope will be all things to all people. The X2000-series is excellent in many ways. You've (belatedly) discovered this isn't one of them.
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I'm in the market for a mso thanks for your research , that is a serious shortcoming IMO Did u know Agilent has an upgrade deal going on right now. U can Get an upgrade on bandwidth (one step up) and all other options are free if u buy one option on an X series scope. If I were u if u purchase was recent get a rep involved maybe go to a 4 channel mso. The offer seems to be retroactive too
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...only Agilent wont trigger and decode on digital serial channels on their "MSO"
Another limitation to watch out for on the 2000 MSO option is digital sample depth. According to it's Spec Sheet,
"Maximum record length 50 kpts per channel (digital channels only)
12.5 kpts per channel (analog and digital channels)"
I'm assuming this is for the standard 100K memory depth, and increases with the 1M memory option? But there's no way to tell from the Agilent documentation. Both their Data Sheet and User Manual are mute on the subject. This is somewhat unusual for Agilent. But that digital acquisition sure seems anemic, with both analog and digital enabled (even if the 1M Option does magnify it by 10x).
Also, you can't even turn the Digital channels on at all, if the Serial Decode is enabled on the Analog side. :wtf:
Lastly, the powerful Search and Navigate capability is only functional with Serial Decode data streams. Nothing else in the analog or digital domains allows you to find & mark desired occurrences, and move between them. The X2000 has a powerful set of trigger conditions (edges, pulse width, patterns, video), but they're useless for Searches. You need to move to the X3000 (or a competitor) to eliminate these limitations.
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I'm in the market for a mso thanks for your research , that is a serious shortcoming IMO Did u know Agilent has an upgrade deal going on right now. U can Get an upgrade on bandwidth (one step up) and all other options are free if u buy one option on an X series scope. If I were u if u purchase was recent get a rep involved maybe go to a 4 channel mso. The offer seems to be retroactive too
The bandwidth upgrade is for the next two weeks. And the "all options" is not free - it's $500 for the 2000 series and $800 for the 3000 series. It also does not include the MSO option, which has to be purchased separately (or purchase a MSO initially).
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in this case, the 4-channel Agilent would be much better as was mentioned already.
The Hameg is quite a bit more expensive if you consider Agilent's current offer + the offer beginning April 1. Hameg does not include CAN but the Agilent will.
Not too sure about the Rigol 4000 series getting to this price range when you add the options for serial decoding, $500 each for the two packages required to cover the main embedded protocols.
bit of a noob here, so I might misunderstand something, but could you external trigger to an analog scope to view the analog signals while you are reading and triggering with the logic analyzer?
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in this case, the 4-channel Agilent would be much better as was mentioned already.
The Hameg is quite a bit more expensive if you consider Agilent's current offer + the offer beginning April 1. Hameg does not include CAN but the Agilent will.
Not too sure about the Rigol 4000 series getting to this price range when you add the options for serial decoding, $500 each for the two packages required to cover the main embedded protocols.
bit of a noob here, so I might misunderstand something, but could you external trigger to an analog scope to view the analog signals while you are reading and triggering with the logic analyzer?
I only use SPI I2C and UART (maybe I2S in the future) I don't need all the others.
From a price point of view Agilent comes out as second most expensive for my intended use (if it was usable) I also want the signal gen. option.
I checked the Rigol spec, it is (with the option I need) better than the Agilent and the price difference is not that big - I think that the Rigol MSO has built in serial decoding, the serial decoding options on their site are meant for the 4 channel non MSO scopes (DSO) (did not check that with rigol but it is very possible).
I can buy a very good old Logic analyzer - I will have very limited (if any) connectivity with the PC, so I wont be able to easily see the data I need.
Besides, Have you seen these old Logic Analyzers, they are huge, it will take up too much space.
I need to see analog and digital signals at the same time to check for delays, correlation , repetitiveness and other fun stuff.
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in this case, the 4-channel Agilent would be much better as was mentioned already.
The Hameg is quite a bit more expensive if you consider Agilent's current offer + the offer beginning April 1. Hameg does not include CAN but the Agilent will.
Not too sure about the Rigol 4000 series getting to this price range when you add the options for serial decoding, $500 each for the two packages required to cover the main embedded protocols.
bit of a noob here, so I might misunderstand something, but could you external trigger to an analog scope to view the analog signals while you are reading and triggering with the logic analyzer?
I only use SPI I2C and UART (maybe I2S in the future) I don't need all the others.
From a price point of view Agilent comes out as second most expensive for my intended use (if it was usable) I also want the signal gen. option.
I checked the Rigol spec, it is (with the option I need) better than the Agilent and the price difference is not that big - I think that the Rigol MSO has built in serial decoding, the serial decoding options on their site are meant for the 4 channel non MSO scopes (DSO) (did not check that with rigol but it is very possible).
I can buy a very good old Logic analyzer - I will have very limited (if any) connectivity with the PC, so I wont be able to easily see the data I need.
Besides, Have you seen these old Logic Analyzers, they are huge, it will take up too much space.
I need to see analog and digital signals at the same time to check for delays, correlation , repetitiveness and other fun stuff.
FWIW come April 1st you can have all the upgrades available (minus bandwidth upgrades) for the 2000X series for $500.