34465A PLC and Trigger Settings - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: August 28, 2020, 10:03:52 pm
content: Ok, rookie 34465A user here - first bench DMM ever..... go easy, plz, Thx.The DMM is in the Number display mode and Continuous acquire mode. For trigger the DMM is set to Auto (maybe a mistake if I want to adjust PLC settings....?)I'm measuring resistance both 2 and 4 wire, and very much enjoying 4 wire (first time ever on that too).Also first time using a DMM with PLC settings (green at everything).I kinda get what PLC settings are - basically the rate of sampling (as a function of Power Line Cycles), yes?So I RTFM and saw it confirms that as expected higher values represent longer PLC sample periods (yes?) and therefore will provide more accurate readings. I have experimented mostly with 100, 10, and 1 but have also tried .02 to .001.What I expected was that as the PLC is set for smaller values (shorter periods, faster sampling) the trigger would run faster, but it seems that the trigger consistently runs with about a 6 second gate no matter what the PLC setting.So, I am concluding that what is happening is that even though the Auto trigger light flashes about every 6 seconds, in the background something (an ADC?) is actually sampling the data faster or slower depending on the PLC setting, but if that's the case - what is the significance of the Auto trigger flashing light (just to tell the user that the trigger is actually working, but not to represent the rate of the sampling process)?Thanks in advance for any guidance or a link to a youtube or a good document on the relationships between DMM trigger settings, PLC settings, and related settings.

author: Grandchuck
author_rank: Super Contributor
timestamp: August 29, 2020, 11:29:11 am
content: My observations at DCV, Auto Range:.002 and .006 PLC = 10.000 displayed and fast flashing of Auto Trigger.02 .06 PLC = 10.0000 displayed, fast flashing.2 = 10.00000, fast flashing1 = the flashing is just noticeably slower10 again a bit slower100 slow (2+ sec)What one would expect but I did not RTFM

author: Electro Fan
author_rank: Super Contributor
timestamp: August 29, 2020, 05:25:43 pm
content: Quote from: Grandchuck on August 29, 2020, 11:29:11 amThanks - I think I had a manual setting set wrong somewhere. I've hit the reset and now the trigger light flash rate seem reasonably in line with what is expected as the PLC settings are changed. User error

author: PushUp
author_rank: Regular Contributor
timestamp: August 31, 2020, 10:08:53 pm
content: Quote from: Electro Fan on August 28, 2020, 10:03:52 pm...Off-Topic...As I also plan to buy my first benchtop DMM, it would be very nice, when you can give some info about the normal usage of your fully packed 34465A - nothing specific, but just your first impression, when dealing with "normal things", which may be obvious for long term users, but strange to newbies, like "stumbling blocks" for beginners...ThanX!

author: Electro Fan
author_rank: Super Contributor
timestamp: September 01, 2020, 12:15:03 am
content: Quote from: PushUp on August 31, 2020, 10:08:53 pmI tried to review the manual and any potential new user should but it's about 600 pages (although nearly 300 are SCPI commands). So, I sorta knew what to expect but not entirely. There are layers and layers and I think it's going to be like the 33522B generator; I use what I need and want to use and along the way I keep finding and learning more capabilities. I can't imagine many people buy these products because they plan on usingeveryfeature - but there is a certain comfort in knowing that for the particular product category if you need a particular capability it's likely to be in there when you need it and in the meantime the measurements and features that you do need or want are reasonably to very accessible, andhighly dependable.So, "normal things".... in no particular order as they come to mind...Beautiful display, can be set for Numbers, Bar Meter, Trend Chart, and Histogram. Trend Chart is pretty flexible for scaling vertically and horizontally and the results continue to populate as you switch between that and Histogram.PLCs - I seem to use 10 and 100 most often.4 wire resistance - it's pretty eye opening to see the difference between this and 2 wire for small values. No big deal maybe but I'd never done 4 wire measurements until now - so you have to take all this with a big grain of salt from a guy who learned most of what he knows about electricity from EEVblog.Temperature - lots to learn about thermocouples, thermistors, and especially RTDs (there's another thread to help any newbies get started, or if you haven't got around to reading up on Pt100 vs Pt1000, etc.).PC communications - Ethernet is easy of course, HTML view is easy, BenchVue is kinda less than intuitive but there's a lot in there to dig out.There is an endless amount you can do with SCPI - I've just started but seems to be only limited by a user's understanding of SCPI.Still a long way to go to figure out Data Log and Digitizing - not sure that Microsoft, Apple, or even Linux is in jeopardy any time soon when it comes to competition for thoughtful interfaces used to do file management.A little disappointed in the fairly limited combinations and uses for the secondary display - seems like this might be an opportunity for a next generation DMM; not sure if the Keithley 6500 (or Siglent?) can do much better.Love the probe hold table for the tests it supports - but spoiler/disappointment alert, it doesn't work with Temperature, Continuity, Diode, or "Ratio".Mostly/overall, the 34465A just instills confidence inthe accuracy of the measurementsand when the readings don't make sense I'm very sure it's because of user error. I don't want to admit how often I've become willing to hit shift+reset after trying to figure out stuff beyond DMM basics. As an example (although it was extra stupid but didn't need a settings reset), today I had a resistance measurement that was off by about 1 milliohm; the meter was telling me .0082 and I was expecting closer to .0096. I think with any other meter I would have thrown my hands up and said, "good enough" or "who besides me cares?". But because it was a Keysight 34465A and I had previously gotten what I was sure was the right measurement I persisted. Turns out it was just my new inexpensive (too cheap plastic sheath over the banana plug?) Kelvin probe that wasn't fully seated in the meter. I think part of what you are paying for with Keysight is that it comes with a stronger PEBCAK indicator than the alternatives.(I haven't even begun to futz around with ACAL - I'm inclined to stay out of there until I'm much more sure of what I'm doing but for someone who really gets metrology I'm guessing it has lots of possibilities.)So, not completely sure what you were asking but I think the "normal things" are all very accessible and the 34465A provides a bridge to the intermediate and more advanced stuff. I think for a user that wants to move from basic to intermediate/advanced it's a very good choice. I'm pretty sure the more difficult choice might be for the intermediate moving to advanced user - especially someone who does a lot of test automation with software scripts, then the 6500 probably has to be in the picture (although if you are adept with SCPI or familiar with BenchVue - then I'm sure there is still a very strong case to be made for test automation with Keysight.) Of course, on the entry level if the budget is being stressed at all, I'd say the Siglent 3055 would get the job done and probably provide some of the same cool UI features (Trend Chart and Histogram) but it might not instill quite the same confidence in accuracy, and bug fixes/ongoing firmware development, and in terms of support (although Keysight doesn't have tautech).All in all, I have been glued to the 34465A for hours per day and I feel like even though I have various other pieces of TE (handheld DMMs, scopes, generators, a SA, PSs, counters, a DC load, etc.) the functions and accuracy of the 34465A are opening up new avenues of learning that I'm mildly surprised have come from a DMM. Part of it is that this is my first bench DMM and part of it is that it's a pretty advanced and very dependable bench DMM.If you were looking to see if I had any buyer's remorse to express, the answer (after one week) is so far, no. To be as candid as possible, I'm very, very happy with the 34465A but I'm not ideologically wed to it; I get why people would buy 6500 or a 3055. For me, the 34465A was the right choice.

author: Grandchuck
author_rank: Super Contributor
timestamp: September 01, 2020, 01:17:21 pm
content: There is areally goodsoftware utility that works with this (and many others) DMM.https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Worth your time to check it out!

author: Electro Fan
author_rank: Super Contributor
timestamp: September 01, 2020, 02:01:00 pm
content: Yep, I’ve been following that thread. It is very good but maybe a little different than TSP.