Products > Test Equipment
Siglent SPD3303X(-E) calibration FW1.01.01.02.07R2 - best practice
BreakingOhmsLaw:
[Nov.11,2023 Updated telnet information]
Hello everybody,
I recently acquired a Siglent 3303X-E, hacked it to 1mV/mA resolution as per the known method.
The calibration on channel 1 was a bit off, so i tried the calibration in the service manual:
https://siglentna.com/wp-content/uploads/dlm_uploads/2019/08/SPD3303C-Service-Mannual.pdf
However, it does not work as stated in the manual, the procedures in the manual are flawed. I always ended up with either the displayed voltage or the actual voltage about 5% off. After much trial and error, here are the correct procedures that ended up getting all values extremely accurate. I hope this saves some of you of going down that rabbit hole.
Some side notes:
- You cannot use EasyPower to send the SCPI commands. It seems to (intentionally?) botch the calibration commands. The best way is to use a telnet client (like https://putty.org/) to establish a telnet connection to port 5025. Or you can use NI VISA MAX instead. If you do, you must use "Write" in the NI VISAVisa Test Panel, not "Query".
- If the unit beeps, it did not accept the calibration command. Check your input. (Use a period, not a comma in the voltage value.)
- I got slightly more accurate results when doing the voltage calibration with a 100mA load rather than open load. It seems to me they are not tapping the sense lines close to the binding posts.
- Check the box at Configuration | I/O Settings | Enable termination character and select "Line Feed \n". Update: not necessary
- you need to restart communication after the power cycles
Follow the procedures closely.
Display voltage calibration
First, clear the voltage calibration values for the channel you want to calibrate:
Channel 1:
*CALCLS 0
*CALCLS 1
Channel 2:
*CALCLS 4
*CALCLS 5
Store with
*CALST
...and power cycle the unit. Edit: Some users report this is not necessary.
Now, hook up the unit to a good multimeter and set the voltage to 1V output.
Both displayed and output voltage should be wrong. Measure the output value with your multimeter.
Set the calibration point 1:
CALibration:VOLTage ch1,1,<measured voltage>
or ch2 if you are calibrating CH2
Next, set the unit to 25V output and set calibration point 2:
CALibration:VOLTage ch1,2,<measured voltage>
or ch2 if you are calibrating CH2
That completes the calibration, but: the displayed value will still be wrong. Don't panic! You now need to change the output value to any other voltage, only then will it update the display using the new calibration value. |O This had me chasing rabbits for 2 hours.
Save with
*CALST
...and enjoy your calibrated PSU.
Current display:
Clear old calibration first:
*CALCLS 3 for CH1
*CALCLS 7 for CH2
*CALST
Power cycle the unit Edit: Some users report this is not necessary.
Set PSU channel to 10V, 3A.
Connect to an electronic load and set it to 100mA constant current. Check actual current with multimeter and enter into the command below:
CALibration:CURRent ch1,1,<measured current value> or ch2 for CH2
Change the electronic load to 2.5A constant current. Again, actual current with multimeter and enter into the command below:
CALibration:CURRent ch1,2,<measured current value> or ch2 for CH2
Store calibration with
*CALST
My unit had <0,5mA accuracy after this.
Current limit calibration:
The calibration procedure in the manual is flawed and will screw up the CC badly.
Do this instead:
*CALCLS 2 for CH1
*CALCLS 6 for CH2
*CALST
Power cycle the unit
Set the electronic load to 3A constant current.
Set the channel to 10V, 500mA (NOT 100mA as written in the service manual!)
CALibration:CURRent ch1,3,<measured current value> or ch2 for CH2
Not set the crrent limit of the channel tp 2.5A
CALibration:CURRent ch1,4,<measured current value> or ch2 for CH2
Now set the current limit of the channel to 2.4A. This updates the CC and actual current should be very close to 2.4A.
Store calibration with
*CALST
The CC should now be within 0,5mA accuracy.
Please post results if you did this.
jeraymond:
Hi, thanks for this info. I was following the guide and using 100mA for the current calibration and it was not working at all. Using 500mA as you suggested worked great!
--- Quote from: BreakingOhmsLaw on November 18, 2021, 12:21:29 am ---
Not set the crrent limit of the channel tp 2.5A
CALibration:CURRent ch1,4,<measured current value> or ch2 for CH2
Not set the current limit of the channel to 2.4A. This updates the CC and actual current should be very close to 2.4A.
Store calibration with
*CALST
--- End quote ---
Here I presume you mean 'Now set the current...'. I also presume you meant 2.5A throughout not both 2.5A and 2.4A.
When I did my cal, I would toggle the channel output on/off after *CALCLS and to see the new calibration parameter in use. I didn't have to power cycle the device.
BreakingOhmsLaw:
--- Quote from: jeraymond on November 29, 2021, 08:52:33 pm ---Hi, thanks for this info. I was following the guide and using 100mA for the current calibration and it was not working at all. Using 500mA as you suggested worked great!
--- Quote from: BreakingOhmsLaw on November 18, 2021, 12:21:29 am ---
Not set the crrent limit of the channel tp 2.5A
CALibration:CURRent ch1,4,<measured current value> or ch2 for CH2
Not set the current limit of the channel to 2.4A. This updates the CC and actual current should be very close to 2.4A.
Store calibration with
*CALST
--- End quote ---
Here I presume you mean 'Now set the current...'. I also presume you meant 2.5A throughout not both 2.5A and 2.4A.
When I did my cal, I would toggle the channel output on/off after *CALCLS and to see the new calibration parameter in use. I didn't have to power cycle the device.
--- End quote ---
Thanks, corrected "Not" to "Now".
Changing the current limit to 2.4A is only done to update the setting. You could also change it and go back to 2.5.
HamDancer:
I did this with my SPD3303X-E upgraded to SPD3303X and it worked great! Thanks so much for putting this together. Despite multiple attempts I didn't quite get 0.5mV/mA accuracy across the entire range, but I definitely got 1mV/mA, and usually much better.
eloso:
Hi,
I was more or less happy with my SPD3303X-E and didn't feel the need for additional resolution on voltage, but getting the additional resolution on current has finally proved a draw for me and I upgraded following the usual instructions (thanks everyone involved!).
Channel 2 was more or less spot-on but channel 1 was out by more than 10mV from the setpoint reading to the displayed reading of output which more or less agreed with the SDM3055 reading of the output. The current was bang-on on both channels.
I followed the calibration procedure just for voltage on Channel 1 and it worked fine the third time. The first twice I can't see that I did anything differently and the commands seemed to be accepted (no beeping) but whenever I went back to the 1V setting I was 200mV out. When it worked the third time I was bemused because I genuinely couln't see what I had done differently and in fact felt a bit foolish for doing something a third time when the first twice had not worked.
So it's a mystery. There will be an answer - there has to be a reason - but I think we will never know it.
Anyway, I have quit while I am ahead - the instrument seems spot on now although I can't comment on any longer term drift or cycling. Its certainly good enough for my purposes as a power supply and even if the absolute accuracy drifts after a while, the resolution is going to be very useful to have just to see short tem relative change in current in the region of mA.
Thanks for providing the extra info here. I guess knowing that others had made this work is what made me perservere. That's why I am posting my own report - it doesn't add anything other than saying, yes, it can work so don't be dejected if it doesn't at first. Or at second.... :)
Regards
Eloso
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