Products > Test Equipment
REVIEW - Rigol DS2072 - First Impressions of the DS2000 series from Rigol
Carrington:
By the way:
Someone in the forum already has a MSO2072A?
::) I'd love to watch a review.
Carrington:
--- Quote from: Teneyes on May 04, 2014, 06:23:55 pm ---A self-criticism :)
--- End quote ---
:) There is nothing wrong, now we know more than before.
Electro Fan:
--- Quote from: Teneyes on May 04, 2014, 06:02:59 am ---Here's a Test to see Frequency tolerance of the Rigol CAN bus Decoding;
The base Frequency was set to max. of 1.0Mb/s and the input message bit rate was raised until an Error and then lower until errors.
Displays;
1: Good decoding at a higher Bit rate (1.087Mb/s) just before Errors occured
2: No decoding at a higher Bit rate (1.111Mb/s) as Errors occur
3: Good decoding at a lower Bit rate (0.877Mb/s) just before Errors occured
4: Error decoding at a higher Bit rate (0.862Mb/s) as Errors occur
So I would say Tolerance is -12% to +8.7 % of Baud rate:
but I am not sure what the theoretical range is?
The timing could be from the the Tigger point, but with 70 bit times there might be re-syncing at the bit change edges
--- End quote ---
Not sure if I'm measuring the same things you are measuring but I found on my 2072 that RS232 decodes reliably in the range of - 6% to 5%. It was at a slow rate and just one test. EF
Teneyes:
Well , maybe I opened the 'CAN'
Let me start will this past discussion of how soon is the DS2000 able to decode the next 'CAN' bus message.?
Here I show you that it depends on the CRC!
If the CRC is correct the DS2000 will decode if there is a 3 Bit times of Idle
If the CRC is Not correct the DS2000 will decode if there is a 7 Bit times of Idle
Here are the Displays:
1: CAN message bursts with Ok CRC has good Decoding at a Interframe space of 6 bit times
2: CAN message bursts with Bad CRC has good Decoding at a Interframe space of 7 bit times, Should do better
3: CAN message bursts with Bad CRC Skips Decoding at a Interframe space of 6 bit times Should do better
4: CAN message bursts with Ok CRC has good Decoding at a Interframe space of 3 bit times
5: CAN message bursts with Ok CRC has NO Decoding at a Interframe space of 2 bit times Could do better
I think this is a BUG and I have reported it to Rigol
Now , although the InterFrame spacing Spec for devices on a 'CAN' bus , is 'to leave the bus idle for 3 bit times , I see no reason for using a DSO as a diagnostic tool to decode Message faster than the devices. Yes, the DSO can scan for the End of Frame (1111111) flag , then open to decode any correct message that follows. Then the DSO should display a RED Bar showing faulty interframe space and the good message.
Teneyes:
Next out of the 'CAN'
Here is a report of the Trigger getting disabled.
When the DS2000 is using 'CAN' trigger on Frame DATA, any adjustment of the display causes the Triggering to Stop
Here are changes that stop the Triggering:
1. Changing the Timebase
2. Enabling Ch 2
3 .Moving the Trigger position or level
4 .starting a Recording
5. moving the vertical position
Pretty much any adjustment
A 'Force' trigger only does a Single Trigger then it stops!
Now one can restart the triggering by changing one of the trigger menu items:
ID, When, ID format, but then you must change it back to what you want
I use 'All bits' and less important ,
Generally a DYSFUNCTIONAL mode
Here are displays
Triggering OK
and stuck in Wait
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