Author Topic: Rigol DP832 - Firmware list and bugs  (Read 239120 times)

0 Members and 1 Guest are viewing this topic.

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #700 on: March 17, 2020, 10:02:02 pm »
@garrettm
It will be more easy to verify the status of calibration if the displayed read value is displayed in real values , not scientific .

step 0, cal point: 0.2v, meas val: -1.54019811E-01
step 1, cal point: 0.5v, meas val: 1.46975726E-01
step 2, cal point: 1.2v, meas val: 8.42319390E-01
step 3, cal point: 2v, meas val: 1.63485328E00
step 4, cal point: 3.2v, meas val: 2.83015883E00

Thank you !
 

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #701 on: March 17, 2020, 10:15:08 pm »
@garrettm
It will be more easy to verify the status of calibration if the displayed read value is displayed in real values , not scientific .

Thats easily doable. I just need to convert the string to a double then print that using printf to format in volts. I'll probably truncate or round at the 4th decimal place since the PSU can only adjust / readback 3 decimal places. The current format is literally what the DMM sends back.

Before I do that though, I want to try testing out new cal points. I've been focusing on using standard low voltage VCC values for the cardinal points. This way, the voltages that are most likely to be used will have tighter accuracy. For instance 1, 1.2, 1.8, 2.4, 2.7, 3, 3.3, 3.6, 4, 4.2, etc. Then switch over to 0.5 volt increments after that and then 1 volt increments.

Let me know what you think. I plan on doing <= 53 cal points per parameter. Hopefully we can fine tune the linearity doing this. I also need to write another script to measure and plot the output and figure out the programming vs output error to see if we can measure an improvement.
« Last Edit: March 17, 2020, 10:29:23 pm by garrettm »
 

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #702 on: March 17, 2020, 10:24:42 pm »
The DMM has a 10 Meg ohm input resistance.  Even if the leads had a total of 1 ohm resistance, the voltage drop would be half a microvolt.

Any 6.5 digit DMM at or below 10 or 20 volts (depending on % overranging) will have >= 10 gigohm input impedance at DC. So negligible loading error.

If I had the results you're showing here I'd be worried. It's saying that the output is quite a bit higher than it should be unless those cables you're using have absolutely no voltage drop? Which is unlikely.
McBryce.

The DP832A can only program upto the third decimal place, and after very recent calibration is maybe within +-2 counts at best. So
Gandalf_Sr DMM reading is actually excellent. The programming error is only around 0.3 counts. I can't see how that is bad in any way.
« Last Edit: March 17, 2020, 11:55:23 pm by garrettm »
 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #703 on: March 17, 2020, 10:26:44 pm »
I also planned by myself to edit list with calibration points from thread with bash script. Tommorrow I will make time for this.
 

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #704 on: March 17, 2020, 11:54:08 pm »
I also planned by myself to edit list with calibration points from thread with bash script. Tommorrow I will make time for this.

I decided to do the print format edit first. Now everything is lined up and prints out values in volts and amps. So no mucking about with annyoing scientific notation. I also reduced the settling time to 2 seconds for volts and 3 seconds for current. This is in anticipation of the larger cal point arrays, which will make the calibration take longer.

Let me know if you have any problems with new changes and thanks for using the script!

UPDATE: There was a minor typo in TelnetTest that I fixed. It would cause the DMM to report an error because of an unfinished measuremnt. Accidentally called readDMM() instead of dmm.read() inside the for loop. Whoops.
« Last Edit: March 18, 2020, 02:32:22 am by garrettm »
 
The following users thanked this post: MegaVolt

Offline McBryce

  • Super Contributor
  • ***
  • Posts: 1696
  • Country: de
Re: Rigol DP832 - Firmware list and bugs
« Reply #705 on: March 18, 2020, 08:35:45 am »
Here's a picture of my calibrated DP832(A) sending 5.000V to my 34461A :D

If I had the results you're showing here I'd be worried. It's saying that the output is quite a bit higher than it should be unless those cables you're using have absolutely no voltage drop? Which is unlikely.

McBryce.

The DMM has a 10 Meg ohm input resistance.  Even if the leads had a total of 1 ohm resistance, the voltage drop would be half a microvolt.

Doh, for some reason my brain hid the 3 zeros between 5 and 13 on the meter. I read 5.013V. Need more coffee.

McBryce.
 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #706 on: March 18, 2020, 12:14:52 pm »

I decided to do the print format edit first. Now everything is lined up and prints out values in volts and amps. So no mucking about with annyoing scientific notation. I also reduced the settling time to 2 seconds for volts and 3 seconds for current. This is in anticipation of the larger cal point arrays, which will make the calibration take longer.

Let me know if you have any problems with new changes and thanks for using the script!

UPDATE: There was a minor typo in TelnetTest that I fixed. It would cause the DMM to report an error because of an unfinished measuremnt. Accidentally called readDMM() instead of dmm.read() inside the for loop. Whoops.

Now it look very good, thank you :

ch1 DAC-V calibration
step  0, cal point:  0.0v, meas val: -0.2345v
step  1, cal point: 0.01v, meas val: -0.2349v
step  2, cal point: 0.03v, meas val: -0.2352v
step  3, cal point:  0.1v, meas val: -0.2554v
step  4, cal point:  0.2v, meas val: -0.1541v
step  5, cal point:  0.7v, meas val:  0.3462v
step  6, cal point:  1.0v, meas val:  0.6448v
step  7, cal point:  1.2v, meas val:  0.8427v
step  8, cal point:  1.7v, meas val:  1.3375v


About extended calibration points . I've done it (using your script) but I don't see any difference. My problems on CH (0-40mV) is still present and can be solved only by manual calibration and other channels are still about the same than before .
1mV output > 1.91mv
2mV output > 2.94mV
3mV output > 3.99mV
I have done better results before . Looks like DP832A cannot benefit from more granular calibration points . Or maybe values must follow a specific algorithm ?
I have attached script used and output .
Maybe you or other can repeat the test . Maybe I was doing something wrong .
 

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #707 on: March 18, 2020, 08:55:56 pm »
@skander36 I've improved the readback accuracy and got ch3 spot on, 1mA and 1mV resolution essentially at all programming values. Ch 1 and 2, however, are a different story as you've seen. I'm still playing around with different cal points for ch 1 and 2 to see if I can get closer to 0mV when programmed to 0 and minimize the "off" state leakage current. Right now leakage is 10mA when off and some 200uA when on and at 0mV. A rather ironic result.

On a side note, I wish Rigol would have put relays in these units to do auto tracking (parallel, series connection internally) and disconnect the output transistor completely. My old GW Instek often times feels superior because of these simple additions. Though I much prefer the screen of the DP832 and its ethernet connectivity.
 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #708 on: March 18, 2020, 10:05:29 pm »
Yeah you cannot have it all  .
What I was want to say is that I cannot improve DP832 over it's limits, so extended range of points seem that doesn't bring more precision .
Your script is working well now and is very usefull for calibrate DP832 into factory specifications .
The others scripts also do the same thing but with more hassle to setup, unless someone make a binary executable for them .
 

Online JDubU

  • Frequent Contributor
  • **
  • Posts: 333
Re: Rigol DP832 - Firmware list and bugs
« Reply #709 on: March 19, 2020, 02:49:18 am »
I've been testing various values and quantities of cal points and it seems like specific values at specific places in the range have more effect than just the quantity of points.  I wish I knew what interpolation algorithm Rigol is using for this and what the DAC hardware resolution is.  I did manage to get all of the channels on my DP832 to be accurate to the millivolt for almost the entire voltage range, but there are  some rare small spots where the output voltage goes off by as much as 3mV.   For example, if I set the voltage to something like 1.423V and then scroll the first digit to the left of the decimal from 1 to 32, the last three digits might be xx.423 for every single volt change except at 19 volts where it will be 19.420.  This occurs even when the cal points were only integer volts between 10V an 32V.  It's weird!

I also discovered that the DAC voltage cal points for my DP832 need to be different between channel one and channel two in order to get millivolt accuracy close to zero on both.  They just do not calibrate the same way with the same cal points.  The list of cal points that, so far, have produced the best results for my DP832 is attached.
 
The following users thanked this post: thm_w, garrettm, skander36

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #710 on: March 19, 2020, 04:25:30 am »
@JDubU thanks! I managed to improve the readback accuracy with using more points and similarly got channel 3 spot on with extra cal points. I also noticed that custom cal points are needed for each channel, as, like you say, they each respond differently during calibration.

I'll give your point list a try tomorrow when I have some free time.

As for the DAC, I would hope Rigol used a 16-bit DAC for ch 1 and 2: 0 to 32 volts at 1mV resolution is 32,001 discrete values--which is about 15-bits. Better to have more bits than not enough. Though they may have cheaped out and used a 14-bit DAC.

As you say, it would be great to get the algorithm they used. It wouldn't be too hard to use Matlab to help optimize the cal point list to better linearize the output. Now that I think about that... I might just set the PSU into cal mode and step through at 10mV increments (using the same "cal step" with just different set values) to see what the raw output looks like. Might go with 1 second settling time, as this will take about 2 hours to collect at 100nplc.
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #711 on: March 22, 2020, 05:45:46 pm »
Hello,

Someone try to calibrate a DP832A using a Keithley DMM6500 ?

I always get error this error "Error -113 Undefine SCPI header"
The error is reported by the DMM...

Any suggestion ?

Many thanks
« Last Edit: March 22, 2020, 05:55:35 pm by Trident900fi »
 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #712 on: March 22, 2020, 06:13:49 pm »
If you connect with Putty and send commands like : *opc? or CONF:VOLT:DC AUTO what you get ?
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #713 on: March 22, 2020, 06:49:33 pm »
Just test with *IDN? and I get "KEITHLEY INSTRUMENT,MODEL DMM6500,04445903,1.7.0e" and the DMM freeze.

With *OPC? I get "1"

With CONF:VOLT:DC AUTO I get "Error -113 Undefined SCPI header" on the DMM and nothing in Putty.


 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #714 on: March 22, 2020, 07:08:24 pm »
*opc? = 1 is ok .
But not ok to freeze .
What port are you using ?
LE - Using a SCPI console on USB you get same result ?
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #715 on: March 22, 2020, 07:38:15 pm »
I use the port use by the DMM. It's the 5025. Actually I run with ethernet port.
I don't know how to manually send SCPI commands in USB ! Sorry, I begin to this area...
 

Offline skander36

  • Regular Contributor
  • *
  • Posts: 236
  • Country: ro
Re: Rigol DP832 - Firmware list and bugs
« Reply #716 on: March 22, 2020, 07:55:54 pm »
You must consult Keysight Keythley product support page for your DMM . Here you will find software and documentation about SCPI. Also you may use software like Ultra Sigma from Rigol or  Command Expert from Keysight to send SCPI commands through USB or Telnet .
If DMM freeze either on USB then you must adapt commands to Keythely SCPI sintax.
« Last Edit: March 22, 2020, 08:33:59 pm by skander36 »
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #717 on: March 22, 2020, 08:02:14 pm »
Thanks for the hints ! I check and I let you know :-)
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #718 on: March 22, 2020, 09:03:45 pm »
Just installed Keysight Connection Expert and command like *IDN?, *RST or *OPC? work fine.
Command like CONF:VOLT:DC AUTO make a error on the DMM

After a *RST command, DMM show only -.------ instead of numbers and stay like this.
With INIT it freeze !
 

Offline bson

  • Supporter
  • ****
  • Posts: 1707
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #719 on: March 22, 2020, 10:06:35 pm »
As soon as you issue an SCPI command the instrument will switch into remote mode and the local panel is disabled.  There's usually a way to regain local control.

*RST disables continuous auto triggering in some instruments, so unless you start a measurement (MEASure), set a trigger, or auto trigger-and-wait (READ) the instrument won't take measurements or display a readout (readout being a calibration data corrected measurement).  My Keithley 2001 works the same; if I recall it also permits choosing what settings to load on reset, with the default being a complete reset with everything disabled (which is more practical for remote operation).
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #720 on: March 22, 2020, 10:40:35 pm »
As soon as you issue an SCPI command the instrument will switch into remote mode and the local panel is disabled.  There's usually a way to regain local control.

*RST disables continuous auto triggering in some instruments, so unless you start a measurement (MEASure), set a trigger, or auto trigger-and-wait (READ) the instrument won't take measurements or display a readout (readout being a calibration data corrected measurement).  My Keithley 2001 works the same; if I recall it also permits choosing what settings to load on reset, with the default being a complete reset with everything disabled (which is more practical for remote operation).

Many thanks for the informations ! I will try again  :)
 

Offline garrettm

  • Regular Contributor
  • *
  • Posts: 150
  • Country: us
Re: Rigol DP832 - Firmware list and bugs
« Reply #721 on: March 23, 2020, 03:10:56 am »
[...] so unless you start a measurement (MEASure), set a trigger, or auto trigger-and-wait (READ) the instrument won't take measurements or display a readout (readout being a calibration data corrected measurement).  My Keithley 2001 works the same; if I recall it also permits choosing what settings to load on reset, with the default being a complete reset with everything disabled (which is more practical for remote operation).

You can also use INIT to begin a measurement, *OPC? to query if the measurement is done and FETC? to move the measurement to the output buffer. Of course, the DMM must be triggered, as you pointed out, either internally, externally or over the bus. I generally let the DMM figure out the triggering (TRIG:SOUR IMM) but you can manually trigger by sending *TRG (if using TRIG:SOUR BUS).

@Trident900fi are you using the Python script or are you writing your own? If you're using the Python script you might want to also get help over at https://www.eevblog.com/forum/testgear/dp832-calibration-using-python-pycharm-running-on-windows/. You can also use my Telnet script if you'd like. If you do, test your setup first using test_run.bat.
« Last Edit: March 23, 2020, 04:06:21 am by garrettm »
 

Offline Trident900fi

  • Contributor
  • Posts: 12
  • Country: fr
Re: Rigol DP832 - Firmware list and bugs
« Reply #722 on: March 29, 2020, 12:18:13 pm »
[...] so unless you start a measurement (MEASure), set a trigger, or auto trigger-and-wait (READ) the instrument won't take measurements or display a readout (readout being a calibration data corrected measurement).  My Keithley 2001 works the same; if I recall it also permits choosing what settings to load on reset, with the default being a complete reset with everything disabled (which is more practical for remote operation).

You can also use INIT to begin a measurement, *OPC? to query if the measurement is done and FETC? to move the measurement to the output buffer. Of course, the DMM must be triggered, as you pointed out, either internally, externally or over the bus. I generally let the DMM figure out the triggering (TRIG:SOUR IMM) but you can manually trigger by sending *TRG (if using TRIG:SOUR BUS).

@Trident900fi are you using the Python script or are you writing your own? If you're using the Python script you might want to also get help over at https://www.eevblog.com/forum/testgear/dp832-calibration-using-python-pycharm-running-on-windows/. You can also use my Telnet script if you'd like. If you do, test your setup first using test_run.bat.

I'm using your Telnet script :-)
My DMM is back to KEITHLEY now. He got a problem with power transformer making hum...
 

Offline Neuromodulator

  • Regular Contributor
  • *
  • Posts: 62
  • Country: cl
Re: Rigol DP832 - Firmware list and bugs
« Reply #723 on: April 24, 2020, 08:33:35 am »
Hello,

I programmed yet another DP832 calibrator in Python https://github.com/Neuromod/DP832-Calibrator. I've found that the when using low V/I values, the calibration isn't that great. I haven't tested that many different value lists, but I got something that gave me acceptable results. I've also used very slow current calibration, so that the measurements are performed at steady-state temperature. Of course the output gets completely screwed up if more or less heat is generated. Still here are some plots I got:

« Last Edit: April 24, 2020, 08:47:37 am by Neuromodulator »
 

Offline alank2

  • Super Contributor
  • ***
  • Posts: 2100
Re: Rigol DP832 - Firmware list and bugs
« Reply #724 on: June 24, 2020, 08:14:34 pm »
Are you guys running the 01.16 firmware now?  I'm on 01.14 - should I upgrade it?
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf