34461A: Line frequency setting wrong after front panel reset - Page 1
Forum section: electronics / testgear

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 03, 2015, 10:17:05 am
content: In the past days I was running some long measurements sequences, and noticed that the measuring times were lower than expected.Long story short: The integration times were corresponding to a device running on a 60 Hz power line while the power line, here in France, is 50 Hz (except any very recent changes).After investigation and some luck, I discovered that if you do a manual reset from the front panel, the DMM is set for a 60Hz power line frequency and all integration times are affected accordingly.This can be checked with the SYSTEM:LFR? SCPI command which isnot documentedboth in the French or English manuals.There are 2 ways to set back the DMM in the correct LF state after a front panel manual reset:1) Power OFF, power ON ...2) Send to the DMM the SCPI command: SYSTEM:LFR 50The SYSTEM:PRESET command which is, according the French and English manuals, supposed to produce the same result than a front panel Reset, don't.While a front panel Reset set the LF to 60Hz, the SYSTEM:PRESET command do not affect it.I don't know how this bug affects the measurements, but for sure, this need to be fixed.I would appreciate to have a feedback from other 34460A, 34461A, 34465A, 34470A user's.My 34461A is running with the latest firmware rev.Thanks for your feedback.Jean

author: VK5RC
author_rank: Unknown
timestamp: May 03, 2015, 11:00:54 am
content: Thanks for the heads up re this issue. I have an Agilent with the newer S-Ware v 2.08 I recall (that adds capacitance and changes the splash screen title to Keysight) , it still has the correct line frequency (for Australia also 50Hz). I am not game to do a front panel reset but suspect mine would do the same.Have you put this on Keysight's blog?ThanksRob

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 03, 2015, 11:07:43 am
content: Quote from: VK5RC on May 03, 2015, 11:00:54 amI have not yet reported to Keysight. I first want to make sure that it is not an isolated issue.I would appreciate if you could confirm it. No risk at all. If the SYSTEM:LFR? command returns a wrong value after the front panel reset, just power OFF/ON your device, and you are back to normal.Thank's for your feedback.

author: VK5RC
author_rank: Unknown
timestamp: May 03, 2015, 11:25:05 am
content: Hi,Mine does as yours does. Mine is a MY53……….LFR upon switch on 50Hz (correct)Front Panel Reset, "resets" to 60Hz,Switch on/off resets to 50Hz.Sorry I am a bit slow but I don't do much computer connected T&M .Kind Regards Rob

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 03, 2015, 12:31:59 pm
content: Quote from: VK5RC on May 03, 2015, 11:25:05 amThank's Rob, seems it's not an isolated issue.

author: 6thimage
author_rank: Regular Contributor
timestamp: May 03, 2015, 01:07:59 pm
content: I've just checked mine and it does the same (I think it's the first time I've used the front panel reset) - I'm in the UK so should be 50 Hz, but it sets it to 60 Hz after a FP reset.

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 03, 2015, 01:12:12 pm
content: Quote from: 6thimage on May 03, 2015, 01:07:59 pmThank's!I've just reported this issue to Keysight Support U.S. with a link to this topic.Wait and see ...

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 06, 2015, 09:18:00 am
content: I got a reply from Keysight France this morning.The bug is confirmed by the product division, escaladed to the R & D division, and they said that a new firmware will be released (ASAP) to correct it.Below is an extract of the reply from Keysight France:...Bonjour Monsieur,J’ai eu un retour de la division qui confirme le bug. Mon contact a envoyé une requête afin que la R&D corrige le défaut au plus vite (je vous tiendrai informé d’une date approximative de la sortie de la release)“Regarding the 34461A changing the line frequency setting to 60 Hz following a front panel reset,this is a defect. . The integration time is relative to the line frequency (stored internally), and there is no rejection of 50 Hz noise once the setting has been changed to 60 Hz. At power on, the line frequency is sensed and stored. The front panel reset unfortunately, overwrites this value with 60 Hz and the instrument uses that value until power is cycled or until the frequency is changed programmatically ...

author: VK5RC
author_rank: Unknown
timestamp: May 06, 2015, 10:24:37 am
content: @OldNeurons, well done, obviously lots of synapses on those "OldNeurons" !

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 06, 2015, 10:42:08 am
content: Quote from: VK5RC on May 06, 2015, 10:24:37 amYes, running at lower frequency than 30 years ago, but no more BSOD !But good to see that Keysight reacted fast. I was not expecting such a quick reply from such a huge company. Now, let see how much time it will take to get the FW release ...Jean

author: OldNeurons
author_rank: Regular Contributor
timestamp: May 11, 2015, 08:51:38 am
content: I received an e-mail this morning from Keysight France saying that a new firmware release will be available within 2 or 3 weeks to fix that bug.That was pretty fast !

author: VK5RC
author_rank: Unknown
timestamp: May 11, 2015, 10:09:57 am
content: That is pretty good work, maybe some of the 'old' attitudes of HP are coming through. Makes me put Keysight up the list when looking at new gear.

author: sotos
author_rank: Frequent Contributor
timestamp: October 21, 2015, 07:55:35 am
content: Is there another way to check what frequency we are in? Without connecting and give commands.