Our Prof. ordered us to purchase one Siglent SDS1104X-E...

[CiscERsang]

Hello everyone,
Our Prof. ordered us to purchase one Siglent SDS1104X-E. It's planned to buy at least a dozen of scopes for the student's laboratory.
Before making decision about buying the rest of scopes, we have to, so to speak, assess the potential of purchased Siglent.
A task is a troubleshooting of misbehaving communication between laboratory equipments (Prof's design, by the way ). The Prof. himself got tired of this annoying malfunction.
So we have on the table brand-new scope right now.

Could anyone guide us (step by step) how to record RS485 packets and analyze if they are ok?
Then we would like to decode sent command from the master and an answer from the slave.

As a side note, we have to record a lot of the same packets. Since the slave answers very rarely with not distorted characters.
As far as we understand, in order to get what happens we have to catch at least one not distorted answer from the slave for further comparison and analyzing.

What we want to record is in the attachment.


Thanks in advance

[tautech]

Please check the firmware version as there is brand new firmware released yesterday that addresses some Decode issues/bugs.
Links here:
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg2431869/#new

[CiscERsang]

Please check the firmware version as there is brand new firmware released yesterday that addresses some Decode issues/bugs.
Links here:
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg2431869/#new

We have 8.1.6.1.26 on board. Do you advise to perform an update at once?

they uploaded no user manual, but two service manuals instead. SDS100X-E. Could you look?

[tautech]

Please check the firmware version as there is brand new firmware released yesterday that addresses some Decode issues/bugs.
Links here:
https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg2431869/#new

We have 8.1.6.1.26 on board. Do you advise to perform an update at once?

Latest version is 6.1.33.
Check the release notes as there is several improvements for Decode

they uploaded no user manual, but two service manuals instead. SDS100X-E.

You can download any documentation here:
https://www.siglentamerica.com/resources/documents/digital-oscilloscopes/#sds1000x-e-series

Scroll down until you see the 1000X-E listings.

[CiscERsang]

Scroll down until you see the 1000X-E listings.

Yes, I was there. Could you tell them that they confused and put two services manuals. There's no user manual under link called user manual. You can check that.

[tautech]

Scroll down until you see the 1000X-E listings.

Yes, I was there. Could you tell them that they confused and put two services manuals. There's no user manual under link called user manual. You can check that.

OK I see.
You can get the user manual here:
http://old.siglentamerica.com/USA_website_2014/Documents/manual/SDS1000X-E_UserManul_UM0101E-E03A.pdf

[tv84]

Our Prof. ordered us to purchase one Siglent SDS1104X-E. It's planned to buy at least a dozen of scopes for the student's laboratory.

@tautech, with this prof your life is simplified! 

[tautech]

Our Prof. ordered us to purchase one Siglent SDS1104X-E. It's planned to buy at least a dozen of scopes for the student's laboratory.

@tautech, with this prof your life is simplified! 

We make little gains in brand awareness every day. 

But some days.........  

[tv84]

We make little gains in brand awareness every day. 

But some days.........  

Maybe it's simpler in the southern hemisphere...   

[Rerouter]

I personally know of 2 Local Tafe's that refused upgrading to new DSO's because they where not aware of the EDUmode stuff to prevent students cheating by just pressing autosetup, so there is probably more business out there for you Tautech. (EDU mode can disable any combination of the autosetup Key, the Measure Menu or the Cursors Menu)

As for the RS485, I'll be getting home this afternoon, I'll have a look, its likely to be using the UART decoder. if its a normal RS485 connection then it can be wired to look like a 0-5V single ended signal

https://www.stratusengineering.com/rs232-rs422485-conversion-cable-connection-requires-no-external-electronics-power/

[plurn]

Could anyone guide us (step by step) how to record RS485 packets and analyze if they are ok?
Then we would like to decode sent command from the master and an answer from the slave.

As a side note, we have to record a lot of the same packets. Since the slave answers very rarely with not distorted characters.
As far as we understand, in order to get what happens we have to catch at least one not distorted answer from the slave for further comparison and analyzing.

I don't know how to do this. But there is some good information (a tutorial) from rf-loop on working with serial decode and history buffer starting at this post which might provide some help:

https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg2096347/#msg2096347

[Fungus]

Please check the firmware version as there is brand new firmware released yesterday that addresses some Decode issues/bugs.

Really?   

[CiscERsang]

We make little gains in brand awareness every day. 

But some days.........  

Maybe it's simpler in the southern hemisphere...   

not sure, the Prof himself came from Europe (quite famous EU tech. uni) and saw there a classroom equipped with Siglents. So, he just had got a peek, I guess. 

[Rerouter]

Ok, a Guide,

- Switch on
- Press green "Default" key, (this just ensures I'm not fighting other settings from before)
- Rotate the "Vertical" knob to set channel 1 to 2V / Div
- Rotate the "Trigger Level" knob to 2V
- Rotate the "Horizontal" knob to fit atleast 1 full communication cycle on the screen, even if there is a big dead gap between the 2 packets, it will be recorded
- Rotate the "Horizontal Position" kbob so the blue triangle at the top of screen is lined up with the right edge of the first division (what you see on the screen is what is decoded,
- Press the "Decode" button (It should default to Decode 1, UART)
- Use the Third from the left UI button at the bottom of the screen to Enter the "Signal" menu
- Use the second from the left UI button at the bottom of the screen to Set "Threshold"
- Rotate the "Adjust / Intensity" Knob to make "Threshold" 2V
- Press the 6th UI Button to go back 1 menu
- Press the 4th UI button to enter the "Configure" menu
- Use the Second Button to set "Custom"
- Rotate the "Adjust / Intensity" Knob to make "Custom" match the "Baud Rate" you are using for your project

.... Continue for the other parameters for your project, this part I'm sure you can flesh out

- Use the 6th UI button to get to the 2nd pag of the "Configure" menu.

.... Continue Setting your Idle level and bit order

Done,

[Fungus]

Ok, a Guide,

- Switch on
- Press green "Default" key, (this just ensures I'm not fighting other settings from before)
- Rotate the "Vertical" knob to set channel 1 to 2V / Div
- Rotate the "Trigger Level" knob to 2V
- Rotate the "Horizontal" knob to fit atleast 1 full communication cycle on the screen, even if there is a big dead gap between the 2 packets, it will be recorded
- Rotate the "Horizontal Position" kbob so the blue triangle at the top of screen is lined up with the right edge of the first division (what you see on the screen is what is decoded,
- Press the "Decode" button (It should default to Decode 1, UART)
- Use the Third from the left UI button at the bottom of the screen to Enter the "Signal" menu
- Use the second from the left UI button at the bottom of the screen to Set "Threshold"
- Rotate the "Adjust / Intensity" Knob to make "Threshold" 2V
- Press the 6th UI Button to go back 1 menu
- Press the 4th UI button to enter the "Configure" menu
- Use the Second Button to set "Custom"
- Rotate the "Adjust / Intensity" Knob to make "Custom" match the "Baud Rate" you are using for your project

.... Continue for the other parameters for your project, this part I'm sure you can flesh out

- Use the 6th UI button to get to the 2nd pag of the "Configure" menu.

.... Continue Setting your Idle level and bit order

Done,

The following users thanked this post: tautech


Looks like everybody here has overlooked step 1 of the task (i.e. the difficult part).

[tv84]

Looks like everybody here has overlooked step 1 of the task (i.e. the difficult part).

@Fungus, enlighten us, please.

[plurn]

Looks like everybody here has overlooked step 1 of the task (i.e. the difficult part).

@Fungus, enlighten us, please.

Ummm.. Connect the probes to the correct places maybe?

[CiscERsang]

Ok, a Guide,

- Switch on
- Press green "Default" key, (this just ensures I'm not fighting other settings from before)
- Rotate the "Vertical" knob to set channel 1 to 2V / Div
- Rotate the "Trigger Level" knob to 2V
- Rotate the "Horizontal" knob to fit atleast 1 full communication cycle on the screen, even if there is a big dead gap between the 2 packets, it will be recorded
- Rotate the "Horizontal Position" kbob so the blue triangle at the top of screen is lined up with the right edge of the first division (what you see on the screen is what is decoded,
- Press the "Decode" button (It should default to Decode 1, UART)
- Use the Third from the left UI button at the bottom of the screen to Enter the "Signal" menu
- Use the second from the left UI button at the bottom of the screen to Set "Threshold"
- Rotate the "Adjust / Intensity" Knob to make "Threshold" 2V
- Press the 6th UI Button to go back 1 menu
- Press the 4th UI button to enter the "Configure" menu
- Use the Second Button to set "Custom"
- Rotate the "Adjust / Intensity" Knob to make "Custom" match the "Baud Rate" you are using for your project

.... Continue for the other parameters for your project, this part I'm sure you can flesh out

- Use the 6th UI button to get to the 2nd pag of the "Configure" menu.

.... Continue Setting your Idle level and bit order

Done,

• unboxing;
• powered up;
• FW was updated to ver. 6.1.33;
• warmed up;
• self-calibration was performed according to manual;
• all probes were marked with corresponding coloured rings and compensated;
• CH1 was hung on line B+;
• CH2 was hung on line A-;
• Press green "Default" key, (this just ensures I'm not fighting other settings from before);
• Rotate the "Vertical" knob to set channel 1 to 2V / Div;
• Rotate the "Trigger Level" knob to 2V;

Further troubles begin...

• Rotate the "Horizontal" knob to fit atleast 1 full communication cycle on the screen, even if there is a big dead gap between the 2 packets,
  it will be recorded;

The point is... Due to master features... in short, it can't send packets continuosly. It works like: a corresponding button is pressed  --> instantly very short transmission occurs. An example: 6E 75 6D 62 72 3F 0A . That means NUMBER?LF.
Then, in less then 10ms the slave answers (half-duplex works this way). An example: 1B 0D 0A. That means 27CRLF.

Is there a way to catch an entire packet? As it's seen, it's very short.

[Rerouter]

I do not know your baud rate, so lets say set horizontal to 2ms/Div, the scope has lots of sample points, so it may appear rather small, I should then add I suppose after setting up the decoders

Can you find out your baud rate,

So for Mk2 so far

Code: [Select]

- Switch on
- Press green "Default" key, (this just ensures I'm not fighting other settings from before)

- Rotate the "Vertical" knob to set channel 1 to 2V / Div
- Press the "2" button to Turn on the second channel
- Rotate the "Vertical" knob to set channel 2 to 2V / Div

- Rotate the "Horizontal" knob to 2ms / Div
- Rotate the "Horizontal Position" knob to -12ms

- Rotate the "Trigger Level" knob to 2V
- Press the "Normal" button for the trigger

- Press "Utility" button
- Press "Next Page" until your at page 4/4
- Press "Reference Position"
- Press "Horizontal" to set it to fixed position

- Press the "Decode" button (It should default to Decode 1, UART)
- Enter the "Signal" menu
- Press "RX" and set to "CH2"
- Press "Threshold", Rotate the "Adjust / Intensity" Knob to make "Threshold" 2V
- Press the 6th UI Button to go back 1 menu
- Enter the "Configure" menu
- Use the Second Button to set "Custom", Rotate the "Adjust / Intensity" Knob to make "Custom" match the "Baud Rate" you are using for your project

.... Continue for the other parameters for your project, this part I'm sure you can flesh out

- Use the 6th UI button to get to the 2nd pag of the "Configure" menu.

.... Continue Setting your Idle level and bit order

- Use the Back button to return to the main decode menu
- Ensure "Display" is set to "On
- Press next Page
- Press on "List"
- Press on "Display" and set to "Decode 1"
- Press the back button
- Press "Format" and change it to "ASCII"

- Run your Device once, the scope should trigger and there should be data on screen

- Press on the "Horizontal" knob to enter zoom mode
- Rotate the "Horizontal" knob twice clockwise to set the text at the top center of the screen to "500us/"
- Rotate the "Horizontal Position" knob to -12ms
- Continue Rotating the "Horizontal" knob clockwise until the first message is clearly visable on screen
- Trim with "Horizontal Position" as needed

This is the master message, the decoder will be on the bottom showing what ASCII it has decoded, the list display at the top hopefully makes it clearer, but sometimes you will need to zoom in furthur for it to show up nicely at the bottom

- Rotate the "Horizontal" knob Counter-clockwise, back to "500us/"
- Rotate the "Horizontal Position" knob to set to roughly -1ms
- Trim and zoom back in as required to show the response message clearly on screen, its the same as above, you may have to zoom in a bit furthur for it to show up nicely on the bottom.




Fungus, I'm still not clear what you think I am missing, you cannot decode on the math trace, If that is what you are trying to get at. If the OP wants me to flesh out all the decoder settings, I will need him to at minimum follow the guide without the decoder section for me to see his waveform and work out the settings.

[TK]

Try using segmented memory to catch both transmission and reception in separate segments, use normal trigger mode

[nctnico]

I think one of the things getting in the way is Siglent's dreaded automatic memory depth selection. If you zoom out at higher samplerates there is no more data to show. Fixate the memory depth to maximum and set the time/div to a value so you can trigger on the first packet and still have time to capture the reply.

[nez]

FYI @CiscERsang, just in case you hadn't seen it, the link for the newest user manual has been corrected (I assume it was fixed after you guys tried it).

The updated manual for the new firmware (6.1.33) is:
UM0101E-E03B
https://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDS1000X-E_UserManual_UM0101E-E03B.pdf

(Note the 'B' )

I believe the previous firmware (6.1.26) uses manual version:
UM0101E-E03A  (shown as UM0101X-E03A inside the doc's title page for some reason)

[plurn]

...

• CH1 was hung on line B+;
• CH2 was hung on line A-;

...

If you are connecting near the master slave devices (short distances), you might be able to get away with connecting to only one of those lines since they are are the same signal with one inverted as your diagram shows. That could free up some memory. Only the polarity of one of them will match up with the decode setting you pick I think you just need to pick the right one. If it was long distances involved, you would probably need some external converter to un-invert and combine them to remove noise and then still only measure a single line on the oscilloscope.

I guess you could separately measure both lines without decode to make sure the signals look properly inverted to make sure that is not an issue.

https://www.csimn.com/CSI_pages/RS-485-FAQ.html

The point is... Due to master features... in short, it can't send packets continuosly. It works like: a corresponding button is pressed  --> instantly very short transmission occurs. An example: 6E 75 6D 62 72 3F 0A . That means NUMBER?LF.
Then, in less then 10ms the slave answers (half-duplex works this way). An example: 1B 0D 0A. That means 27CRLF.

Is there a way to catch an entire packet? As it's seen, it's very short.

See my earlier post Reply #10 linking to a tutorial on using history buffer (Segmented memory as mentioned by TK). Should allow you to capture lots of packets.

Or - if you don't want to read everyones suggestions and join the dots for yourself, just get a Siglent sales engineer to do your homework for you with the promise of a big order if they get it right.

[Fungus]

Looks like everybody here has overlooked step 1 of the task (i.e. the difficult part).

@Fungus, enlighten us, please.

RS485 is a differential bus, you don't just connect a probe to a wire to diagnose it.

Ummm.. Connect the probes to the correct places maybe?

Which would be....?

[Rerouter]

RS485 under controlled conditions with a ground lead provided can be done with just 1 wire, add external noise e.g. in a vehicle or complicated installation and you would be correct.

The SDS1104X-E does not let you decode on the math trace, so to treat it like a proper differential bus would require an external RS485 to UART or similar converters, like I linked in an image earlier.

The third alternative if the RS485 device is battery powered or not ground referenced. Connect your scope ground lead to Data- and the scope channel 1 signal to Data +, this way it is treated deferentially. done this many times with vehicle Canbus / J1708 (which is RS485)