Sample rate for digital channels on a Agilent MSOx3000 - Page 1
Forum section: electronics / general

author: RRobot
author_rank: Regular Contributor
timestamp: May 26, 2012, 10:18:54 pm
content: I'm trying to make up my mind whether to order a Agilent MSO 3000 series. I checked the spec sheet but cannot see any sampling information related to the 16 digital channels on the MSO. Anyone know if I can assume the sampling rate is the same as the analog channels?How is memory divided up for the 16 channels, if say only 4 are in use, do I have 512 KB each?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 26, 2012, 10:40:27 pm
content: I think the granularity for digital channels, in terms of memory usage (& sample rate at lower speeds for peak/glitch detect) is either blocks of 8 , or all 16 on or off.Thinks like using peak detect and which permutation of analogue channels on 4-channel models also affect this. I'm sure there will be a section in the manual on this.

author: RRobot
author_rank: Regular Contributor
timestamp: May 26, 2012, 10:46:47 pm
content: Thanks for your response Mike.I found the sample rate section in the spec sheet under "Horizontal system digital channels", not sure how I missed it.It appears its 1 GSa/sec per channel and 1 Mpts/channel (or 2 Mbps/channel with the 4 Mbs upgrade), which is much more than I expected, which makes me think I am missing a caveat somewhere.

author: free_electron
author_rank: Super Contributor
timestamp: May 27, 2012, 12:15:58 am
content: No you're not. Agilent doesnt muck about with sharing a/d converters and memory between channels. They never have. Even on the relly old machines. The only exception is their top of the line machines. There you can interleave the samplers to double the sampling rate, but there is still one converter per channel.

author: NeilR
author_rank: Newbie
timestamp: June 23, 2012, 10:45:48 am
content: Quote from: RRobot on May 26, 2012, 10:18:54 pm@RRobot - One tip I have is to look in the user manual. Sometimes the specifications given in the user manual contains more information than the datasheet.Also I can confirm that on the 3000X, that the digital system is exactly the same on all bandwidth models up to 500MHz.

author: EEVblog
author_rank: Unknown
timestamp: June 23, 2012, 10:57:56 am
content: I wonder if my unit will get higher digital sampling rate when it gets upgraded to 1GHz?I'm presuming not, but I haven't checked.Dave.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 23, 2012, 11:07:23 am
content: Quote from: free_electron on May 27, 2012, 12:15:58 amI think they do, certainly memory, not sure about ADC - you can see the sample rate halve when you have channels 1+2 running. No change when 1+3 are on. Enabling digital channels also reduces available sample length

author: EEVblog
author_rank: Unknown
timestamp: June 23, 2012, 11:18:43 am
content: Quote from: mikeselectricstuff on June 23, 2012, 11:07:23 amCorrect. The sample rate is halved with two channels. They use a shared ASIC for both channels, two ASICs for 4 channel, hence you can use the CH1/3 trick.I believe it's one ADC per channel (two per ADC ASIC)I just checked, and the 1GHz model gets an increase in sample rate on the digital channels to 1.25GS/shttp://cp.literature.agilent.com/litweb/pdf/75019-97051.pdfDave.

author: NeilR
author_rank: Newbie
timestamp: June 23, 2012, 02:39:28 pm
content: Quote from: EEVblog on June 23, 2012, 10:57:56 amDave - As far as I've been told, you will get the full specifications of the 1GHz when you upgrade to it.See page 32 of the brochure -http://cp.literature.agilent.com/litweb/pdf/5990-6619EN.pdfNeil