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SDS 1202 X-E I2C triggering bug

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17_29bis:
The last bit. I think I understand the reason why the I2C trigger condition  "7 bit Address&Data" does not work when  the payload contains only a  single byte.  The documentation is very scarce, so I decided to add some explanations, may be it will save some times to other users of this device (may be I am just not savvy enough).

Looks like the idea behind I2C trigger condition  "7 bit Address&Data" is to have a fixed length, 2 byte floating window/mask  which applies to the decoded data (those 2 "DATA1 & DATA2 values).   0xXX value is used to indicate that this particular data byte will be ignored/can be ANY.

The o-scope manual says: "If the data's value is 0xXX any value data will be matched". But in this particular case ANY does not mean  NONE and this is important.

So if you want the o-scope to trigger  on the byte 0x33 (i.e. not the first and no the last byte)  the trig. condition  can be defined as:

a) 0x33  0xXX
b) 0xXX  0x33

The only difference is the time when the triggering occurs:
a) 0x33  0xXX

b) 0xXX  0x33


if you want the o-scope to trigger  on the last byte 0x0F  the trig. condition  should be defined as:  0xXX 0x0F (a) . If the condition is defined as 0xF  0xXX (b)  the o-scope will  not trigger at all because the data byte corresponding to 0xXX does not exist in the payload.

a)  0xXX 0x0F

b) 0xF  0xXX


if you want the o-scope to trigger  on the first byte 0x13  the trig. condition  should be defined as:  0x13 0xXX . If the condition is defined as 0xXX 0x13 the os-cope will  not trigger at all because the first byte (defined as 0xXX) does not exist in the payload.


And finally is you set the mask 0x01 0x0x0F the trigger will  not work because those data bytes are supposed to be adjacent while in this particular example they are separated by the byte 0x33.


17_29bis:

--- Quote from: Performa01 on January 27, 2018, 10:11:59 am ---Not sure what you mean by "averaging trigger mode".

--- End quote ---
Was it me? Then sorry, I am not sure what I meant, I don't know what "averaging trigger mode" is.


--- Quote from: Performa01 on January 27, 2018, 10:11:59 am ---Data Length Trigger works with the length of Address and Data in bits. This trigger obviously is only useful in a system with mixed message formats, where you want to trigger any messages that fit the format you've set for the decoder. Not sure how often this will see use in real applications - at least I for one have never seen let alone designed such a mixed format system on a single bus. This makes only sense for a multi-master system, which I've always tried to avoid at all costs.

--- End quote ---
I have never seen such config either - 2 different sets of devices using 7/10 bit addr. sharing the same bus and was just curios how it can be used. But my career of the embedded hardware/software engineer ended 25 years ago therefore my knowledge is outdated, the terminology is rusty.


--- Quote from: Performa01 on January 27, 2018, 10:11:59 am ---Regarding the differences between SDS1202X-E and SDS1x04X-E you might want to have a look here:
https://www.eevblog.com/forum/testgear/siglent-sds1104x-e-in-depth-review/
But your specific questions are not explicitly answered there, so here is what I can tell:
A lower input capacitance is always nice of course, but 15pF vs. 18pF really doesn't make a noticeable difference in practical terms.
SDS1x04X-E scopes never had missing caps, because that problem was discovered before the first production units of this scope have left the factory.
The "E" in X-E stands for Economy. These are entry level scopes - albeit rather capable ones. But they don't feature an internal 50 ohm termination like the 1000X (without the “-E”) and 2000X do. In my review I have closely examined the input impedance of the SDS1104X-E with external termination.

--- End quote ---

I have already returned SDS1202X-E and waiting for an answer from the seller regarding availability of 1204X-E, they have to contact Siglent first. I would say that SDS1202X-E fits my hobbyist's needs almost perfectly but I do want to have 4 channels ( I will also get wifi adapter and the software  to control the device from PC)  -I realized that only now.  I have a standalone logic analyzer but after playing with serial decoding on 1202X-E I decided that it has its own merits - I think there will be times when I use the oscilloscope rather than the logic analyzer for decoding those protocols (but not always). That is why I decided to upgrade.  I am also considering 2204X since its nice to have higher time sampling rate (2 vs 1 GSa/s) and more memory but in Canadian dollars it is around 3K while  SDS1202X-E is 1K CAD.
 

--- Quote from: Performa01 on January 27, 2018, 10:11:59 am ---The "E" in X-E stands for Economy.

--- End quote ---
Yes, I noticed that when I was running the built-in keypad test  (you press a button and check its response on the o-scope screen) - on my 1202X-E some buttons required multiple presses. One of those buttons was single trigger and it was kind of annoying. But like you said "E" stands for economy  :(. Other than that - I really liked this o-scope!

tautech:

--- Quote from: 17_29bis on January 30, 2018, 07:45:37 am ---I have already returned SDS1202X-E and waiting for an answer from the seller regarding availability of 1204X-E, they have to contact Siglent first.
--- End quote ---
If your seller has no stock of the 4ch models there's unfortunately a wait right now for production to match demand.


--- Quote ---I would say that SDS1202X-E fits my hobbyist's needs almost perfectly but I do want to have 4 channels ( I will also get wifi adapter and the software  to control the device from PC)  -I realized that only now.
--- End quote ---

The WiFi dongle is a TP Link TL-WN725N, gold version and more cheaply available from other sources than Siglent. You'll still need the 'WiFi software enable' option: SDS1000X-E WIFI

No software is needed for PC control as the scopes inbuilt web server only needs a free LAN IP address for connectivity and operation.
Use an 'ipconfig' command in a DOS box to get one close to your PC and use that.
Open a browser window and input the scope's assigned address and hey presto, connection.

If you liked the 1202X-E you'll be impressed with the 4ch models.

rf-loop:

--- Quote from: 17_29bis on January 30, 2018, 07:45:37 am ---
Yes, I noticed that when I was running the built-in keypad test  (you press a button and check its response on the o-scope screen) - on my 1202X-E some buttons required multiple presses. One of those buttons was single trigger and it was kind of annoying. But like you said "E" stands for economy  :(. Other than that - I really liked this o-scope!

--- End quote ---

This is not at all normal.
I have never seen this in any X-E model what I have checked. (Normally I check every unit before end user).

Only one single problem I have meet it was in my own very early production X-E (my own demo unit) where one encoder was bit bad. Perhaps damaged in factory or shipping. This one encoder works kind of bit randomly some times. After then contact with Siglent and new front panel board solve problem.

This your individual unit need repair. This kind of problem is not acceptable at all. E do not mean C (Crap).
There is warranty. Use it. This is only way to teach Siglent about quality control.  It is also expensive way to teach hands washing and learn the use of clean gloves and the importance of general cleanliness in the assembly of equipment.

Others want to learn and develop themselves. Others should be taught. There is a difference between the Western and Chinese industries. The top-down command system is not the best possible development environment. From the floor cleaners to the top management, each one should be one motive - the desire to learn and bear responsibility for quality - each assembly worker should think that quality is just my responsibility and I want to do quality. How can this idea be exported to China?

(as you can read I may quess what is problen in your front panel. It is not normal but some times some worker may break rules and eat example chicken toes and then... asssemble next front panel..)

Performa01:

--- Quote from: 17_29bis on January 30, 2018, 07:45:37 am ---I have already returned SDS1202X-E and waiting for an answer from the seller regarding availability of 1204X-E, they have to contact Siglent first. I would say that SDS1202X-E fits my hobbyist's needs almost perfectly but I do want to have 4 channels ( I will also get wifi adapter and the software  to control the device from PC)  -I realized that only now.  I have a standalone logic analyzer but after playing with serial decoding on 1202X-E I decided that it has its own merits - I think there will be times when I use the oscilloscope rather than the logic analyzer for decoding those protocols (but not always). That is why I decided to upgrade.  I am also considering 2204X since its nice to have higher time sampling rate (2 vs 1 GSa/s) and more memory but in Canadian dollars it is around 3K while  SDS1202X-E is 1K CAD.

--- End quote ---

Be aware that WiFi is an option (I’ve not tried it yet). In my review I have demonstrated the use of the web server (using a wired LAN connection) and its limitations.

Regarding DSO/MSO vs. LA it is good to meet someone who knows to use the proper tool for a specific task. Serial decoders are just an add-on for a DSO/MSO and are not meant to replace a dedicated protocol analyzer. But a MSO with serial decoding capabilities can be a great tool for low level signal integrity checks and fault finding, especially when the time relation between Analog and digital signals as well as bus telegrams needs to be examined, which is what a MSO should be used for in the first place.
High level communication monitoring/debugging on the other hand is a task for an LA/protocol analyzer.

The SDS2204X serial decoders are limited to what’s currently visible on the screen. For example, after zooming into a long record, the list view will get shortened accordingly and context to the entire data record is lost. Especially for I2C, decoding may stop working as soon as the start condition of a message has been scrolled outside the visible screen area. Generally, these scopes have less processing power, so automatic measurements only use up to 70/140kpts of the acquired data (still vastly better than many other DSOs!) and FFT is limited to 16kpts.

Still, an SDS2kX series DSO/MSO is a great tool for analog work and also mixed signal with the MSO option. It has a larger screen and despite the lower processing power, its user interface is still snappier than on the SDS1000X-E and the max. waveform update rates (both standard and sequence mode) are faster. Of course it also has some higher class features like internal 50 ohm termination, automatic probe sensing and gold plated input connectors.

I would say, if you can live with 1GSa/s and 200MHz nominal bandwidth (more like 240MHz in practice), the SDS1204X-E is a clear price/performance winner.



--- Quote ---Yes, I noticed that when I was running the built-in keypad test  (you press a button and check its response on the o-scope screen) - on my 1202X-E some buttons required multiple presses. One of those buttons was single trigger and it was kind of annoying. But like you said "E" stands for economy  :(. Other than that - I really liked this o-scope!

--- End quote ---

The sometimes unresponsive buttons and controls are certainly not a “feature” of the “-E” models. Vertical and horizontal encoders sometimes miss a notch, but this simply is a firmware bug which should be sorted eventually. I haven’t experience unresponsive buttons though, so this might be a specific issue of your unit. As you’ve already returned it, you should make your supplier aware of the issue, so they don’t pass on a defective unit to the next customer.

If you liked the SDS1202X-E, you will most probably like the 1204X-E even more – a lot more. It still has bugs in some areas, but they will get fixed sooner or later.

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