New Keithley DMM6500 and now DAQ6510

[MegaVolt]

I put together a precision PWM DAC and automated a test with 0.5V steps from -9.5V to +9.5V.

Perhaps there is a topic about this DAC? Or his scheme? Or any other information?

[Pinörkel]

Hello,
I just got myself a DMM6500 and it mostly fulfills my expectations. However, aside from being annoyingly noisy, the screen quality on my unit is kind of abysmal. When the unit stands on my desk and is, consequently, viewed from a 45° downwards direction, the contrast ratio of the screen gets incredibly low, the image gets blurry and shows a very pronounced doubled image with a strong vertical offset (see attached image). When viewed directly from the front or from an upwards viewing direction, the image looks OK. But when viewed from just a slight 10° downwards direction, the double image issue is very pronounced and reading small text becomes incredibly tiring to the eyes. To me, it looks like the build in panel has bad viewing angles, combined with a reflection issue between the display/touch layers. I cant remember ever seeing a small sized touch screen with such a bad image quality, not even on cheap smartphones. Now, I am trying too figure out if this is normal or if my screen is defective. Has anybody here experienced similar issues with the DMM6500? I tried to compare the screen quality of my unit to several youtube videos using roughly the same viewing conditions, but could not see this effect there.

[HighVoltage]

.... Now, I am trying too figure out if this is normal or if my screen is defective. Has anybody here experienced similar issues with the DMM6500? I tried to compare the screen quality of my unit to several youtube videos using roughly the same viewing conditions, but could not see this effect there.

The screen of my DMM6500 is very crisp and I am very happy with it.
Something is wrong with your screen and you should exchange the instrument.

[Joel_l]

That seems odd about the screen. Did you take the protective film off?

[Pinörkel]

Thank you for your replies. The screen protector is off. I have attached two more images including small text.
Just found a probably related topic on the Tek forum with a reply which seems to be from a Keithley official: https://forum.tek.com/viewtopic.php?t=140802
Looks like a known issue.

[Evodad]

This is my little Christmas endeavor, contribution into making my Keithley DMM6500 much more quiet.

I bought the instrument more than two years ago. I really like things to be quiet in my Lab so this new wonderful Keithley came to shame
with its really loud fan. It was also very buggy, blue screens almost all the time. Some Firmware revisions later, 1.03, and it was usable.
Due to the fan it became a dust collector, just using it occasionally for some special measurements and not as my every day companion in the lab.
Some weeks ago when turning the instrument on the dates where reset back to 1970. Digging into this it became clear that Keithley
had made a mistake draining the backup battery to quickly and there was also a new FW that should correct it to some extent.

This battery issue became the start of the modification. To summarize:

    • Change of Battery. (Broke the battery holder, had to make a special solution).
    • Update to latest Firmware (FW). Not painfree, but almost.
    • Ventilation holes in lid.
    • Move the original Fan and modify it with a diode in series to slow it down.
        ◦ It could probably have been run Fan-less, see measurements and links at the end.

Sorry to say but Keithley seems to have cut corners in this design, especially around the power supply, thereby wasting a lot of power into heat.
    • They have used two transformers in parallel with low primary inductance's making the standby power more than 6 W.
       So yes, have a switch turning the instrument of completely!
    • Used linear regulation for the analogue parts with very large voltage margins.

See attched PDF with my report. Not complete in any way but I hope it helps !

)) Per

N.B ! Disclaimer. If you do this you do it at your own risk. I can't be held responsible in any way!
(Should probaly not have to write this here )

[The Soulman]

The linear regulators need some voltage drop (a few volts) to function properly, but yes anything above is wasted as heat.
If your mains voltage is nice and stable, you could run the meter on a lower mains voltage from a external (diy) autoformer or variac.
How much lower depends on the voltage margins on the regulators and the stability of the mains.

According to the datasheet it shouldn't be a lot tho, they specify only a 10% mains voltage margin.

Power supply 100 V, 120 V, 220 V, and 240 V (±10%)

I don't get why the mayor brands can't produce fan-less precision devices anymore.

[Kleinstein]

A problem with transformers switched between 230V and 115 V is that the US also has 60 Hz and Europe 50 Hz. If they ignore the 50Hz the transformer would be driven to higher magnetization and has quite a bit of no load current.  In the US they may have got transformers for 230 V 60 Hz.
The supplies to the analog and digital board need good isolation from each other - a single transformer would need to be very special. With 2 transformers only the one for the analog supply needs to be a little special (with shield, but still a standard bobin).

It is a little odd they need so much power - here the large scree probably needs quite some power.
The problem can be running such a DMM in a hot rack - there you may need a fan already with a relatively low power level.

[Evodad]

Thank you for your responses.

You will have to design a 50/60 Hz transfomer for 50Hz then the 60 Hz won't be a problem. I have not checked if this transfomer i easily switchable between
115 and 230 VAC. They migth have two different transformers.

Linear regulators. Yes, you need to drop some voltage but there are readily available LDO's (or you can design a discrete one if you are price sensitive)
and then you can drop far less. An LM317, LM337, which Keithley uses need some 1.5 to 3V drop to work properly.

The current design has -22.6 VDC after rectification on one of the rails, the negative, feeding a LM337 to -15V. If we count backwards. -15V +20% = -18V and a LDO wiith 1V margin,
then we end up with -19V. The positive rail is regulated to 16.7V and not 15V. My guess is that it became too much for the LM317 so they decided to increase this rail
to 16.7V to take some heat on the connected circuits on the PCB instead. (For sure, they migth have had resons which we don't see for the desisions they have made).

I can say it's a joy using the instrument now

[KedasProbe]

If I remember correctly, the DMM design itself can work without fan it's the added heat on the front/display panel that is the 'problem'
And they can't just update the display, that's part of a bigger plan.
But I think they are probably already busy thinking on the next screen to be used for the next updated design platform.

It's also possible to turn the display off and only watch the screen via LAN, maybe someone should test the temps/drift with fan and screen on vs display off and fan off.

[Mr. Scram]

A problem with transformers switched between 230V and 115 V is that the US also has 60 Hz and Europe 50 Hz. If they ignore the 50Hz the transformer would be driven to higher magnetization and has quite a bit of no load current.  In the US they may have got transformers for 230 V 60 Hz.
The supplies to the analog and digital board need good isolation from each other - a single transformer would need to be very special. With 2 transformers only the one for the analog supply needs to be a little special (with shield, but still a standard bobin).

It is a little odd they need so much power - here the large scree probably needs quite some power.
The problem can be running such a DMM in a hot rack - there you may need a fan already with a relatively low power level.

Risking repeating myself, but it seems multiple generations of earlier devices were able to deal with different voltages and frequencies no issue. If the screen is that much more power hungry, maybe a hybrid with a transformer for the reference and sensitive parts and a switching module for the power hungry part could be a solution. Switchers can deal with different inputs without issue or much compromise.

Mind you, I understand that I don't know much about the compromises made so maybe there are very good reasons for this approach. It's just such a shame to have those niggles which impact liveability in an otherwise superb machine.

[The Soulman]

A problem with transformers switched between 230V and 115 V is that the US also has 60 Hz and Europe 50 Hz. If they ignore the 50Hz the transformer would be driven to higher magnetization and has quite a bit of no load current.  In the US they may have got transformers for 230 V 60 Hz.
The supplies to the analog and digital board need good isolation from each other - a single transformer would need to be very special. With 2 transformers only the one for the analog supply needs to be a little special (with shield, but still a standard bobin).

It is a little odd they need so much power - here the large scree probably needs quite some power.
The problem can be running such a DMM in a hot rack - there you may need a fan already with a relatively low power level.

Risking repeating myself, but it seems multiple generations of earlier devices were able to deal with different voltages and frequencies no issue. If the screen is that much more power hungry, maybe a hybrid with a transformer for the reference and sensitive parts and a switching module for the power hungry part could be a solution. Switchers can deal with different inputs without issue or much compromise.

Mind you, I understand that I don't know much about the compromises made so maybe there are very good reasons for this approach. It's just such a shame to have those niggles which impact liveability in an otherwise superb machine.

Yep, efficient multi-rail switchmode psu's are cheap and plentiful these days, everything digital in the dmm can be run straight from it or thru a LDO if needed.
The analog section (and adc) need to be isolated (5KV?) that could be efficiently done with a (small) multi-tap high frequency transformer powered from the smpsu and traditional LDO as post regulators.
Can't see this being any more costly than the transformer setup in the dmm6500.

@Kleinstein, yes I know all about 19 inch racks, stacking equipment and managing btu's, I've looked
at the dmm6500 product page and there isn't even a rackmount available.
Mounting two side by side wouldn't work anyway because it would block the fan openings on the side.
So maximum one (22 Watt) dmm per two rack heights, nothing a well vented rack couldn't handle.

Overall it seems it could have been designed/engineered a little bit better.

Ps, no hard feelings E-design, we are being very picky.

[E-Design]

A problem with transformers switched between 230V and 115 V is that the US also has 60 Hz and Europe 50 Hz. If they ignore the 50Hz the transformer would be driven to higher magnetization and has quite a bit of no load current.  In the US they may have got transformers for 230 V 60 Hz.
The supplies to the analog and digital board need good isolation from each other - a single transformer would need to be very special. With 2 transformers only the one for the analog supply needs to be a little special (with shield, but still a standard bobin).

It is a little odd they need so much power - here the large scree probably needs quite some power.
The problem can be running such a DMM in a hot rack - there you may need a fan already with a relatively low power level.

Risking repeating myself, but it seems multiple generations of earlier devices were able to deal with different voltages and frequencies no issue. If the screen is that much more power hungry, maybe a hybrid with a transformer for the reference and sensitive parts and a switching module for the power hungry part could be a solution. Switchers can deal with different inputs without issue or much compromise.

Mind you, I understand that I don't know much about the compromises made so maybe there are very good reasons for this approach. It's just such a shame to have those niggles which impact liveability in an otherwise superb machine.

Yep, efficient multi-rail switchmode psu's are cheap and plentiful these days, everything digital in the dmm can be run straight from it or thru a LDO if needed.
The analog section (and adc) need to be isolated (5KV?) that could be efficiently done with a (small) multi-tap high frequency transformer powered from the smpsu and traditional LDO as post regulators.
Can't see this being any more costly than the transformer setup in the dmm6500.

@Kleinstein, yes I know all about 19 inch racks, stacking equipment and managing btu's, I've looked
at the dmm6500 product page and there isn't even a rackmount available.
Mounting two side by side wouldn't work anyway because it would block the fan openings on the side.
So maximum one (22 Watt) dmm per two rack heights, nothing a well vented rack couldn't handle.

Overall it seems it could have been designed/engineered a little bit better.

Ps, no hard feelings E-design, we are being very picky.

Haha     I know you all are a picky crowd indeed! Its great to see all the feedback (good and bad)
I consider the user base on here expert and very knowledgeable. So its a good thing. You might be surprised about how difficult it can be to get good feedback from large / corporate customers. 

Switch-mode power supplies would be more expensive for this design considering the isolation and noise requirements. Of course a switch mode design *could* be done, but for cost & performance reasons it didnt make sense for this product (both DMM and DAQ) Some design aspects were leveraged from the older DAQ Models 2700 and 2701

Also regarding the heat issue and fans.. the front panel processor and the power needs for the DAQ module drove the requirement for a small fan. Many of the folks on here do not have the DAQ model, but the transformer design accommodates both products so there were some considerations for that model that went into the X-former design. And rack mounted equipment can get quite warm. As such the product specs to 50C ambient.. and BTW, I am surprised to see there is no rack mount kit? If I recall, certainly no new rack kit was designed, but perhaps another kit is compatible with it. I can find out for sure if anybody is interested.

[Evodad]

Yes, really good feedback can be hard to get by and when you get it, it's almost alway too late in the process.

In my litte report on the previous page I have linked to several of Brad O's comments about turning off the Fan should be okey.
Do also realize that I have read that in the current design it is not possible to turn the Fan off, you just have two settings,
LOW and HIGH and default is LOW. If you don't want the Fan to spin you can always unplugg the Fan connector . You have to remove the front to do that.
(Brad O proposed to just block the Fan from the outside). If you block or disconnect the Fan the instrument will get quite hot even on the outside,
that is why I kept the Fan. (My personal guess is. if running fan-less, that the hotest components on the PCB's will be 75-80C with a 20C ambient and
more or less freestanding instrument. So, yes, at 50C ambient things will start to get too hot !)

E-Design, why not engage us for your next design. A DMM6500 Mk II ?    it's been done...

[KedasProbe]

Without fan you do reduce the lifetime and it will not be within spec, so you have to consider if that's ok for you.
a bit reduced fan speed is probably a good middle ground for everyone.

[E-Design]

....
@Kleinstein, yes I know all about 19 inch racks, stacking equipment and managing btu's, I've looked
at the dmm6500 product page and there isn't even a rackmount available.
...

Just FYI for anybody interested. part#s  4288-1 for single and 4288-2 for double are the rack mount kits for Model 65xx.

https://www.tek.com/search?keywords=4288-1

[The Soulman]

....
@Kleinstein, yes I know all about 19 inch racks, stacking equipment and managing btu's, I've looked
at the dmm6500 product page and there isn't even a rackmount available.
...

Just FYI for anybody interested. part#s  4288-1 for single and 4288-2 for double are the rack mount kits for Model 65xx.

https://www.tek.com/search?keywords=4288-1

Thanks, but how would the double mount work with respect to the ventilation openings?

[KaneTW]

There's a spacer that should be sufficient.

[Kleinstein]

With the rack mount kit's check with the length of the screws:  with some of the newer meters there was a problem with too long screws that could hit something on the inside.  You don't want to damage the screen or touch some high voltage or only reduce the needed clearance to much.

[Bugsyson]

Keithley / Tektronix / Kickstart , a heads-up

Your “permanent” Kickstart License that came with your DMM6500 or other Keithley or Tektronix test gear as a promotion, was false advertising, and a bait and switch scheme to get you to pay for it later.
 
I reinstalled window on the same PC, no hardware changes, reinstalled KickStart, and it generated a new “Host ID” making the .LIC file I was sent unusable. Contacted customer support, and was told sorry nothing we can do, your options are buy a license or “The most likely solution beyond that would be to try to recover the original windows installation” So the software is good for one install only, any changes render it useless. As quoted by Keithley “The license we provided at no charge is still functioning as intended.” As in you will be paying for it soon enough.

 To realize just how bad this is, I was looking to buy 32 DMM6500 for our labs, because the software at that time was free (always looking for the best bang per buck in a School environment) so compared to other options, this was a big plus.

Now imaging after I recommended these meters (I bought one with my own money to test and use at home) That My IT department decided to upgrade the computer in the Labs, and now all the software stops working. I now have to go to my Boss and ask for $42,000 to buy the software, that I told everyone was free (and why I chose the meters), or the 100’s of man hour spent developing new Lab course material will be wasted and have to be rewritten, 100’s of more man hours. I believe I would keep my job, but?

The main thing that stopped this scenario from playing out was budget cuts. The meter is great, the support and customer service, not so much. Of the hundreds of pieces of test equipment I will be purchasing over the next few years, not thinking any will have the Keithley Tecktronix logo on them, does not seem they need or want my business, or care.

[idolclub]

DMM6500 New Firmware v1.7.5 Release - 04/Jan/2021:

https://download.tek.com/software/supporting_files/DMM6500-FRP-v1_7_5_Dec_2020_RNs_DMM6500-FRP-V1.7.5.pdf

[KedasProbe]

Keithley / Tektronix / Kickstart , a heads-up

Your “permanent” Kickstart License that came with your DMM6500 or other Keithley or Tektronix test gear as a promotion, was false advertising, and a bait and switch scheme to get you to pay for it later.

Actually it was not but they sure made it confusing (due to an second promotion) to get what they promised.
If you bought the device when the promotion was still running then you can claim the full license. (but you had to contact them)
The node locked license you get when you register your device is not the free license that you could get, that's the one time install license. (I think it was (is?) valid for all touchscreen devices)

I bought two, one for home and one at work, both are still using the one time install license because I haven't changed the PC yet (I had to wait to get the other one) but I also have 2 accounts each with an unused license waiting for me that I can move from one computer to another.
https://www.tek.com/products/product-license  (if you bought them during the promotion you should get them in here: see screenshot)

There is more info in this long thread about it, the promotion ended now but if you ordered it on time you can claim the free license that you can move around.

[Evodad]

There is more info in this long thread about it, the promotion ended now but if you ordered it on time you can claim the free license that you can move around.

How do you claim your right to the software ?

Reading in the link below does not get me too excited, but perhaps I missunderstand ? (Interpretation: From october 2021 you are stuck with that version of Kickstarter, if you want the latest you will have to pay)
https://www.tek.com/support/faqs/kickstart-licensing-faqs

Answer :
1. I see that KICKSTARTFL-BASE is going away. Will the existing KICKSTARTFL-BASE license still work in KickStart version 2.4.0?
a. Yes.
b. However, by October 2021, existing KICKSTARTFL-BASE users will need to purchase KICKSTARTFL-SUITE-UP to use their Base licenses with KickStart software versions released after that date.

[KedasProbe]

There is more info in this long thread about it, the promotion ended now but if you ordered it on time you can claim the free license that you can move around.

How do you claim your right to the software ?

Ask the seller first, if they can't figure it out ask a Customer Sales Representative of your country (@tektronix.com), they will ask for serial number etc.
For my work I went via the seller, for home I went directly to @tektronix.com that did go much faster.
But since the promotion ended it may be trickier to get it done for an old purchase, not sure.

Yes indeed I see they won't give free updates anymore after end this year, ah well, didn't expect much updates anyway.

[KedasProbe]

DMM6500 New Firmware v1.7.5 Release - 04/Jan/2021:

https://download.tek.com/software/supporting_files/DMM6500-FRP-v1_7_5_Dec_2020_RNs_DMM6500-FRP-V1.7.5.pdf

fixes for scan cards...

Does anyone have an practical idea/example how this below was a problem?

The "Branch to Block" setting on various branch blocks on the Trigger Flow screen on the front panel now allows a minimum value of 0.