RoadTest: Keithley Bench Digital Multimeter
Author: Jan Cumps
Evaluation Type: Test Equipment
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: Keysight 34xx
What were the biggest problems encountered?: I could not get KickStart remote software working on my PC
I road tested the Keithley Bench Digital Multimeter DMM6500.
This report documents my experience. There are links to in-depth reviews throughout the post.
The DMM6500 is a 6½ digit multimeter. This is an advanced instrument that is targeted at these applications:
This extract from Keithley marketing material gives an overview of the highligts.
source: product page
The meter arrives well packed. The instrument is well protected and the packaging is designed to withstand abuse.
The display and BNC inputs are covered. It survived the trip from Chicago to Schaarbeek in good order.
Next to the DMM6500, the box includes power cord, a pair of 100 V CAT II meter probes and a USB cable.
The documentation consists of a read-me-first, info related to environmental regulations and the calibration certificate:
image: scan of my calibration certificate
The meter isn't small. It's the common 2U half width rack unit. For a desk meter i'ts long, almost 40 centimeter.
It's not that heavy, 4.5 KG. The fan can be heard in a room with background noise. It's not silent.
The screen is clear and sharp, 800 x 480 resolution. The screen stays readable at an angle.
The touch screen function works good and precise. I am not a touch and swipe expert but things went fine for me.
All functions are accessible from the front, and so are most connections.
Only the 10 A current input, external trigger connectors and connectivity options are at the rear.
Next to the screen, there are 8 function buttons. Three of them (APPS, HELP and FUNCTION) I have barely used since day one.
There's a USB connection to plug in a memory stick. It can host scripts and apps. You can store measurement results to it. HOME + ENTER saves a screen print.
The button to switch between front and rear connections is a heavy, clunky one. This function is not programmable.
The power button is a soft one. The meter switches on immediately. To switch it off you have to hold the button a second.
Startup tile is short. The meter is functional after a few seconds.
Keithley advises to let it warm up for 30 minutes before taking precision measurements.
The inputs are shrouded. I had no problems using a non-shrouded banana plug with them. The meter is CAT II.
Front and back are protected by rubber buffers. They are long enough to protect all connectors and buttons of the instrument.
They will not protect any extending objects like plugs, test leads or a USB stick.
The feet on the front allow the instrument to be tilted up for better reading when on the desk.
I would not put another instrument on top when in tilted-up position. The construction doesn't feel strong enough for that.
I am not confident enough to open the device. But other users have done that and they took high-definition photos of the inside.
Next to the teardown and photos, they also offer a review and comparison with competitive meters.
They are deep reviews, from engineers that have more experience with comparable meters
They include details on the voltage reference, operating temperatures and other highlights.
Please check them out.
source: xdevs.com Selected LM399AH voltage reference with Keithley marking on top
During my test of the instrument (I used it extensively and tried all functions I could practically review), I never had a hardware hiccup.
The instrument consistently performed as it should and I have zero complaints about its physics and quality.
The picture is a little different for the software part, but luckily that's something that can be improved by upgrades.
As a pure bench instrument, the meter has the below functions and ranges:
source: product page
What stands out is the lower end of the ranges, and the resolution, for voltage, current and resistance.
The diode function is flexible. It allows you to test LEDs that require a little more oomph to light up.
In the lower capacitance readings, I found it hard to avoid interference from about anything around.
Looking at a probe impacted the measurement. But that's not the meter's fault. Similar as with any other low scale meeting, this requires proper setup.
The period and frequency measurements are useful, but I prefer an oscilloscope for those. Personal opinion.
The meter is not restricted to the options listed in above infographic.
Next to the meter functionality, there's are automation and scripting options.
The instrument supports the proprietary TSP (based on LUA) scripting language and SCPI. It has an emulation mode for two popular meter families.
SCPI and TSP can't be combined. You have to choose the language. Switching requires a reboot.
(Keithley, if you can put a bigger processor in your next instrument, please reconsider this. I see value in storing on-instrument TSP scripts to digitize measurements and do statistics, then execute these remotely from LabVIEW with SCPI).
The scripting options allow to combine and refine the functionality and to fully integrate the DMM6500 in a test setup.
You can make custom Apps to adapt the meter's interface and behaviour.
This can go from simple situations, where you show queue cards to the operator during setup, to a full customized GUI that shows multiple key measurements on a single screen.
You can find more info later on in the review.
USB and LAN/LXI are supported by default. GPIB, RS-323 and proprietary TSP-Link are options.
External Trigger In and Out allow you to chain the meter with other instruments to make interdependent measurements (and more).
You can turn this from a single input to a 10 channel meter with expansion boards. These aren't cheap though (all options are pricey relative to the instrument base price).
The TSP-Link allows you to let multiple Keithley instruments to talk together in native mode.
This is very powerful and allow you to do things that other vendors don't support. On the other hand, this is also very supplier-buy-in.
I don't think that is a problem, but it should be a parameter that you take along in your decision making process.
The quality of the user interface was the biggest surprise. I'm conservative and think that touch screens are for millennial telephones.
This instrument shows I am wrong. The GUI is well designed and the touch screen is an essential part of it.
Keithley managed to render a number of complex functions into intuitive manipulations on the front screen.
I was able to use many of the features right away, often without using the manual. That's a sign that the flow is natural.
Keithley didn't turn a menu based GUI into a touch screen menu base system. Instead, they made good use of screens, swiping and pinching, visual hints.
USB-only instrument designers (and any instrument designer offering a PC front-end to their device) should have a look at this meter and maybe try to model their GUI on the DMM6500 front panel user experience.
image: showing the simplicity of the user interface
Information on the home screen is clean. If you want, you can display nothing more than the measurement.
Access to additional screens works via swiping. I find the available set of screens well balanced.
Additional functions and fine-tuning of settings are available via the MENU button (and the (never used by me FUNCTION button).
The graph screen could use some improvements. The predefined functions and scale manipulations are OK.
Selecting data source and related functionality are easy too.
Some of the horizontal and vertical scale settings felt a little magical though - and once I started to zoom in and out, I had a hard time making it return to its defaults.
All in all, this has been the best on-instrument user experience I've had with a complex lab device until now.
Please check my links at the end of this review for a detailed review.
Keithley has a number of solutions.
There are basic but powerful utilities like Communicator. A little program that lets you send commands to the instrument straight away.
They have the Test Script Buider (TSB), an Eclipse based environment to develop, test and debug scripts. This is a powerful tool.
If you are not relying on SCPI, this is the easyest way to automate the instrument. If you want to fully customise it, then it's your only option.
note: I could partially lock up the instrument while running some TSP scripts. The Keithley-provided amp-hour script from their application note Data Logging of Power Profiles from Wireless IoT and Other Low-Power Devices
turns the user interface non-responsive at times, in particularly when you work with the graph screen. Not always, but repeatable.
The instrument still works. Canceling the script turns it back to normal.
Keithley also provide KickStart 2 kit. This is a generic remote access application.
You can try it out for a limited amount of time. When I got the instrument, Keithley ran a free node-locked free license campaign.
It does not wok on my PC - I have an issue that's reported to be resolved in the version I have. Please check other road tester's reviews.
The Keithley support analyst has worked with me to a great extend to try and resolve this problem. We could not fix it but the use experience with the support desk is great.
There is also an extensive LabVIEW library, with examples. I've used this a lot during my review (it was my main focus) and you can read my experience in the detailed posts linked in below.
The quality for single measurement flows is perfect. They work out of the box.
I had issues trying the scanning examples. It seems that they have been developed on a meter where the trigger model was already set up. They error when I run them, except if I add trigger functionality myself.
I think there are error in a few of the blocks. Again related to the trigger functionality, I found examples where the LabVIEW flow created invalid SCPI syntax and the instrument complained.
For both instances, I've posted an entry on the Tek community forum. Let's see how that works out. No reaction at the moment.
In general, the LabVIEW driver is well-balanced and (for a device with so many options) easy to use.
I haven't seen a development environment for Apps. TSB doesn't support them, even though the language is the same TSP.
There are three mayor ways to automate the instrument;
The SCPI support is mature. Keithley has supported this since forever.
The syntax is very close t what you can do with Keithley's TSP language remotely.
I could add DMM6500 measurements to an existing flow in hours. The examples helped me to understand the specifics for this meter.
Advanced functions - like digitising - and triggering took longer to understand. As mentioned before, I think Keithley has errors in the examples and external trigger blocks.
I have working examples of those functions (see the links below) but had to modify basic blocks for that and insert functionality in the examples.
image: measurements captured with a LabVIEW flow
Except for that, if you know SCPI and LabVIEW, then using the DMM6500 in an integration setup is an achievable exercise.
TSP (Test Script Processor) language is Keithley's scripting language. According to rumours, the instrument optimised for that.
The language is on Lua. The API is Keithley specific.
It offers more than SCPI. While with SCPI you can automate, with TSP you can change the behaviour of the meter.
image: custom pop-up designed with TPS
I can't dig deep into this in the road test review report, but the links at the end link to detailed reviews and my examples.
One of the examples I did was to modify the Keithley Amp-hour script to a script that uses an EEVblog µCurrent to measure a low-energy device.
The most inventive option that the meter has is Apps. t least if you are in a situation where you want to adapt it for a particular purpose.
Apps allow you to bypass the user interface, and use TSP to build your own one.
If this instrument is used in a production line, an App could be used to guide an operator through the setup steps, execute your validations and then spawn a test report.
Another possibility is to create custom displays that show the main indicators of a test run (KPIs for the buzzword sensitive crowd), or multiple measurements.
Keithley has an interesting example that can show all measurements of a 10-channel extension card on the display - at a single time.
There aren't a lot of other examples around, but I can see this as method to make life easier for people using the instrument in repeatable situation (if the working environment is touch screen friendly ).
I'd like to get hold on a channel expansion card - maybe on the second-hand market. Or make my own. I've seen the schematic and the components are available.
With that, I can further investigate the automation options of the DMM6500. But that's for later ...
In the meantime, I asked fellow element14 members for things they want to see tested. They came up with advanced exercises that I'm not up to yet.
But when I gain experience with the meter, I might be able to deliver on that.
I scored this meter high overall, almost 9/10. It's a quality product and I noticed that each time I worked with it.
Here's a clarification on the scores I gave:
Product Performed to Expectations: 10
Product was easy to use: 9
It does. I did not have a situation where the instrument played up or measurements were off.
The touch screen makes the instrument easier to use from the front panel than comparably complex instruments.
The triggering setup is reasonable good but less intuitive than other advanced settings. The touch screen workflow could be streamlined.
Specifications were sufficient to design with: 10
The price to performance ratio was good: 9
Yes. The meter has specifications that will be more than many of us need.
In its price class, the precision, resolution and sample speed are very competitive.
Demo Software was of good quality: 7
Support was available: 7
I score the Test Script Builder and the remote utilities very high. Well designed and easy to use.
Points are lost for software and support, because KickStart 2 does not work and I found errors in the LabVIEW driver.
Support helped me well with KickStart 2, prompt and polite reply, good analysis. But no resolution for a defect that was listed as fixed with this version.
I posted two questions on the community forum related to LabVIEW errors but there was no activity on there.
This seems to be more of a Tek / Keithley communication outlet than a thriving user community.
The remarks I gave here are all related to support, firmware and software. They are easy to incrementally improve on.
I can't find a single point of critique on the hardware. Quality overall.
They are a good match for the DMM6500 4W Ω and Voltage Ratio functions.
|Software Control Options Pt 1 - TSP Script Builder, LabVIEW, Web Interface|
|TSP Script Example - Measure Power|
|How to Create a Bitmap for a Custom App|
|Verify a µCurrent Manually|
|Verify a µCurrent in an Automated Setup|
|Measure Amp-Hours of a microcontroller with a µCurrent|
|Trigger from External Trigger Input|
|Trigger from External Trigger Input in LabVIEW|
|Software Control Options Pt 2 - Test Commands with Communicator|
|App to Hold Measurements|
|Store Multiple Measurements Manually|
|Keithley DMM6500: Script Example - Externally Triggered Measurements|
Thank you element14 and Keithley for allowing me to review the DMM6500. I'm impressed with the instrument and this was a great experience.
I hope that my review helps interested parties to assess if this meter fits the requirements.
I enjoyed your review and I live vicariously each time one of these up scale products are reviewed. Thank you for your usual thorough job and excellent explanations.
Excellent report and extensive blogs.
It was great that you showed many practical things concerning the meter, such as how to control it using scripts and apps, this was interesting to learn!!
rachaelp, if you want to try it out for a period, and I can try your DC load for that same period, I’m open to that.
Very good test report.
The RTC backup battery is empty in my device. It seems to happen with several people all at a similar lifespan of approx. 18 months.
The calibration interval documented by Keithley for this device is up to 2 years. Means you may have to void your calibration sticker before cal expired ...
Although the manual says it's not user replaceable, I will try anyways. There are instructions available. I'll document my experience.
I've added a new blog: Keithley DMM6500: Store Multiple Measurements Manually
When you want to add a measurement to an on-screen list by pressing a button.