Author Topic: Rigol DP832 - Firmware list and bugs (Read 312094 times)

Armxnian · « **Reply #300 on:** April 23, 2015, 06:51:28 am »

Anyone else have the bigger display read higher than the smaller display? Mine reads 4mV higher than what is set for many voltages. Even set at 0v, the big displays shows .004. Some voltages like 11v show the same reading. My multimeter shows I'm getting what I set it to. It's quite annoying that the big displays is higher, makes it a bit useless. I'm on the latest version and have the higher resolution enabled.

H.O · « **Reply #301 on:** April 23, 2015, 11:02:04 am »

What do you mean with "the big and small display"?
On the main user interface the numbers at the bottom displays what you've got it set to and the larger number in the middle of the screen is what the metering circuit in the supply measures the actual voltage at the output terminals to. Try shorting out the supply, the set voltage stays at whatever while the actual voltage goes to zero, or very close to it.

Quote

It's quite annoying that the big displays is higher, makes it a bit useless.

If they were to display the exact same value all the time it would either have to actually BE the same value (ie either the set value OR the actual value) and THEN it would be useless and a waste of screen real estate or the internal circuitry would have to be extremely accurate so that the actual output voltage always matched the set output voltage down to the least significant digit. A 4mV difference between the set value and the readback value is well within its specifications (which is 0.05%+20mV on the set voltage and 0.05%+10mV on the readback).

Oh, and the high resoultion option means you can set the output voltage in 1mV increments (instead of 10mV increments). It doesn't mean that the absolute accuracy of the actual output voltage OR of readback circuitry is increased.

If you still think it's useless, put a piece of electrical tape over it....

Then again, perhaps I completely misunderstodd what you meant by bigger and smaller display in which case you can simply disregard the above.

Armxnian · « **Reply #302 on:** April 23, 2015, 03:03:53 pm »

You understood correctly, and all your points are true in regards to the hardware. I just thought it was some weird software bug that offset the reading by +4mV since it was present on almost every setting, even with the output set at 0. But further testing today confirms other values, like +2,3,4,5,6mV at different settings, so everything is functioning correctly.

LaurentR · « **Reply #303 on:** April 23, 2015, 04:13:52 pm »

Quote from: Armxnian on April 23, 2015, 03:03:53 pm

You understood correctly, and all your points are true in regards to the hardware. I just thought it was some weird software bug that offset the reading by +4mV since it was present on almost every setting, even with the output set at 0. But further testing today confirms other values, like +2,3,4,5,6mV at different settings, so everything is functioning correctly.

For some data on the DP832 DAC and ADC, see this thread:
https://www.eevblog.com/forum/testgear/noob-dac-linearity-in-the-dp832/

The bottom line is that the DAC has a resolution of about 0.5mV. Its linearity across the range is not great and varies strangely (from -5mV to +10mV, see the graphs), even after calibration. There is a noticeable temperature coefficient. The ADC is entirely separate (thus the discrepancy on the display between the DAC setting and the ADC readout) and seems to be much more precise and accurate (more or less +/- 1mV across the range).

If you have access to a good bench DMM, you can recalibrate your DP832 yourself (see the first post of this thread). But you'll still see the readout vary by +/- 10mV across the range.

broderp · « **Reply #304 on:** April 23, 2015, 06:51:16 pm »

Quote from: Armxnian on April 23, 2015, 06:51:28 am

Anyone else have the bigger display read higher than the smaller display? Mine reads 4mV higher than what is set for many voltages. Even set at 0v, the big displays shows .004. Some voltages like 11v show the same reading. My multimeter shows I'm getting what I set it to. It's quite annoying that the big displays is higher, makes it a bit useless. I'm on the latest version and have the higher resolution enabled.

Normal. (As others have posted) I'm following this thread and links and just wonder how much more it would have cost ROGOL to incorporate some sort of feed back to compensate for the voltage drift and attempt to 'regulate' it to match the set display. Maybe they do and this is the best it can do?

My unit (no hi-res option) when powering up to the DEFAULT mode shows CH1 & CH2 at 00.01V and CH3 is dead on at 00.00V. It does appear to fluctuate somewhat, but I believe it's still within spec. Under load it may not match the set point, but as long as its solid and doesn't change significant, I'm OK.

Either way, for my needs its fine.

Armxnian · « **Reply #305 on:** April 23, 2015, 10:02:42 pm »

Here is an example. CH2 set at 2.000V, and SDM3055 showing a dead on 2V, but the readout is 4mV more. So the readout is not always more accurate than the set voltage. The dmm accuracy (.015%) is negligible for this specific measurement and it was calibrated only a month ago. The readout is however within spec.

Guni · « **Reply #306 on:** April 23, 2015, 10:16:31 pm »

Everything is ok. Check the specification of DP832.
Power supply is not a high accuracy voltmeter

broderp · « **Reply #307 on:** April 23, 2015, 11:39:28 pm »

Quote from: Guni on April 23, 2015, 10:16:31 pm

Everything is ok. Check the specification of DP832.
Power supply is not a high accuracy voltmeter

My humble opinion would agree with this. If the circuit I design or am working on is so sensitive that 4mV is a problem, then I'm doing something wrong..

Armxnian · « **Reply #308 on:** April 24, 2015, 01:48:26 am »

Yup everything is indeed in spec. As mentioned, I originally thought it was a software bug (and the read back was bang on) since everything read 4mV higher. Today for example, with the channel on and set to 0V, I read 2 to 3mV instead of 4mV. A feedback loop as another member mentioned could have helped, but you would need more accurate components anyway for such a circuit. It's just weird setting 2V, actually getting 2V out, but the PSU telling you its a little above 2V when its not, making you fine tune it, when in reality you are drifting away. Of course this is not the case on all voltage ranges, and what you set is not what you get, so the read out is just another reference.

H.O · « **Reply #309 on:** April 24, 2015, 05:46:29 am »

Geez, I can't believe the things some of you guys worry about - just sayin'

It's a power supply, and a pretty good one for what we're paying for it, not a precision voltage reference.

Quote

So the readout is not always more accurate than the set voltage

They don't claim it to be. Actually the set voltage has a tighter specification than the readback voltage. <---EDIT: No it doesn't.

It's just a matter of time before someone says they're sending the unit back because the warranty seal sticker wasn't put on at exactly straight.

Said with tounge- in-cheak....mostly

EDIT: Nope, I got the programming vs readout backwards. Readback is 0.05%+10mV, programming is 0.05%+20mV.

LaurentR · « **Reply #310 on:** April 24, 2015, 05:53:04 am »

Quote from: H.O on April 24, 2015, 05:46:29 am

Quote
So the readout is not always more accurate than the set voltage
They don't claim it to be. Actually the set voltage has a tighter specification than the readback voltage.

It was my impression that the readout was specced more accurate (0.05%+10mV instead of 0.05%+20mV for programming). It is also my experience (after calibration).
Note that the programming side takes several minutes to be stable, so expect several mV differences between cold and warm.

Armxnian · « **Reply #311 on:** April 24, 2015, 06:51:16 am »

The data sheet says the set voltage accuracy is .05% ±10mV, and the read back is .05% ±5mV. So theoretically the read back is more accurate, but both are always in spec so it doesn't matter.

Also I'm not complaining, just sharing observations. The unit is awesome in performance and bang per buck.

H.O · « **Reply #312 on:** April 24, 2015, 07:58:50 am »

Yep, I got that backwards.
Programming is 0.05%+20mV, readback is 0.05%+10mV (on Ch1 and Ch2). Sorry about that!

Armxnian · « **Reply #313 on:** April 24, 2015, 08:38:14 am »

Where does it say 10 and 20mV offset? I see 5 and 10mV under annual accuracy.

H.O · « **Reply #314 on:** April 24, 2015, 09:57:31 am »

Page 5-1 in the manual.
Link goes to the Aug 2014 revision of the manual available from Batronix.

Armxnian · « **Reply #315 on:** April 24, 2015, 07:38:37 pm »

The specs on the rigol product page and data sheet give different values. I would trust those values over the manual.

broderp · « **Reply #316 on:** April 24, 2015, 08:43:39 pm »

Quote from: Armxnian on April 24, 2015, 07:38:37 pm

The specs on the rigol product page and data sheet give different values. I would trust those values over the manual.

hmmmm..it sure does doesn't it..

I'm ok with that....

netdudeuk · « **Reply #317 on:** April 25, 2015, 06:09:53 am »

I adore my DP832 but since I used the OCP option, even when it's set to off, switching on the channel sometimes causes the OCP message to appear with the power being turned off. Anyone else seen this ? I've not upgraded he firmware since I bought it in November.

kjdotts · « **Reply #318 on:** April 25, 2015, 06:36:36 am »

Quote from: netdudeuk on April 25, 2015, 06:09:53 am

I adore my DP832 but since I used the OCP option, even when it's set to off, switching on the channel sometimes causes the OCP message to appear with the power being turned off. Anyone else seen this ? I've not upgraded he firmware since I bought it in November.

I have not personally experienced that issue or encountered it anywhere online. If it was my unit, I would update the firmware (currently v00.01.13.00.01, bootloader v01.09, released 2014-11-18) and maybe reset everything to the default presets. If the issue still occurs, try to nail down what sequence of events creates the issue. If it's a firmware bug and you can recreate the issue then you could report it here and to Rigol.

Good Luck!

-Kris

netdudeuk · « **Reply #319 on:** April 25, 2015, 07:00:05 am »

Don't you have to re-calibrate after updating the firmware ? If it needs some extra kit, that's not something that I could do. Also, as mentioned above, it looks like Rigol don't say what the updates fix and so there's no guarantee that I'd be better off.

kjdotts · « **Reply #320 on:** April 25, 2015, 07:31:14 am »

Quote from: netdudeuk on April 25, 2015, 07:00:05 am

Don't you have to re-calibrate after updating the firmware ? If it needs some extra kit, that's not something that I could do. Also, as mentioned above, it looks like Rigol don't say what the updates fix and so there's no guarantee that I'd be better off.

No recalibration required. I've performed several firmware updates on two different Rigol DP832 units and they have never affected calibration. It's true we don't know exactly what was added/changed/addressed in the most recent firmware update. However, the issue you describe sounds like a firmware issue so I would update the firmware as a troubleshooting step. Just carefully follow the instructions HERE (pdf). Naturally, there are risks anytime you update firmware so you have to make that decision.

-Kris

broderp · « **Reply #321 on:** April 25, 2015, 03:01:30 pm »

Quote from: netdudeuk on April 25, 2015, 07:00:05 am

Don't you have to re-calibrate after updating the firmware ? If it needs some extra kit, that's not something that I could do. Also, as mentioned above, it looks like Rigol don't say what the updates fix and so there's no guarantee that I'd be better off.

I asked this as well as the response I got from RIGOL was:

"We have high confidence in our updates, but there are always risks. We leave it to users to weigh what the update helps them do vs the potential risks. I see no reason it should need calibrated after the fact.

Regards,
Chris

Chris Armstrong
Director of Product Marketing & SW Applications
Rigol Technologies
10200 SW Allen Blvd. Suite C
Beaverton, OR 97005
office/fax: 877-4-RIGOL-1 x110
mobile: 440-781-4982
email: chris_armstrong@rigol.com"

Teneyes · « **Reply #322 on:** April 25, 2015, 05:16:35 pm »

Quote from: broderp on April 25, 2015, 03:01:30 pm

Quote from: netdudeuk on April 25, 2015, 07:00:05 am
Don't you have to re-calibrate after updating the firmware ? If it needs some extra kit, that's not something that I could do. Also, as mentioned above, it looks like Rigol don't say what the updates fix and so there's no guarantee that I'd be better off.
I asked this as well as the response I got from RIGOL was:
"We have high confidence in our updates, but there are always risks. We leave it to users to weigh what the update helps them do vs the potential risks. I see no reason it should need calibrated after the fact.
Regards, Chris Armstrong

Altough I do not have the DP832 ,
I have found that the Rigol FW updates change the Calibration on the DS2000. And rightly so, as if there is a new feature added in the Software that makes a better/different calculation then there will be a change.
In my experience with changing FW back and forth. I have seen the Calibration change , but once I go back to the FW where the calibation was done , ALL still has the same Calibration.
I change FW to check for FW bugs. Is this a new bug or previously existing Bugs; (back 7 FW updates + x beta)

I assume Chris hopes a FW update happens easy and un-eventful

thn788 · « **Reply #323 on:** May 03, 2015, 07:47:16 pm »

Seems there is new firmware for the DP800 available. Rigol's firmware update request form lists 00.01.14 firmware for the DP800. Anybody got this version already or any information what has been changed?

Macbeth · « **Reply #324 on:** May 04, 2015, 12:28:09 am »

I've just got the new firmware 01.14 by automatic email. It includes the existing bootloader 1.09.

Interestingly it also includes an 18 page document mostly in chinese detailing all the firmware releases and their changes to date

The changes from 01.13 are:

1. Change the USB Device library. (Mod)
2. Change the LXI and SCPI library. (Mod)
3. Add the Series-parallel help info in the main help. (Enchancement)

So, clear as mud then. I'm yet to install it...


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Author Topic: Rigol DP832 - Firmware list and bugs (Read 312094 times)

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