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R&S RTB2004 noctua fan questions/feedback
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alonsojar:
After some testing with the Noctua NF-A8 FLX fan here is my experience

The Noctua runs faster, more or less 150rpm faster than oem Sunon in the same conditions. Both fans are rated 2.000 rpm +-10% but for any reason the Noctua runs faster.
Maybe the fan control is made using a temp reference and setting a predefined voltage. Then fan speed sensor is only used to veriry fan is turning? I'm not an expert in that.
In this condition, the noise produced by Noctua is noticeably higher.

After some further testing, loading the fan with a 33 Ohm resistor I can see the same speeds the Sunon had. The noise is perhaps a little less disturbing, but in my phone app it is only reduced 2dBA, so it's negligible.
I was also monitoring temperature sensor readings for CPU, ADC and FPGA using SCPI interface and I observed some increase when using the Noctua (2 to 4 degrees), so probably Noctua spinning at the same speed is less effective than Sunon.

Conclusion... Rydda experience was confirmed. Probably the noise main source is not the fan itself but the air passing though the device propelled by a fast running small fan. The Noctua NF-A8 is not improving noise and shows a different behaviour. At the end I left the Sunon because I don't want to risk my oscilloscope integrity.

Thank you all for your contributions
J. Alonso
Rydda:
@alonso

--- Quote ---I was also monitoring temperature sensor readings for CPU, ADC and FPGA using SCPI interface and I observed some increase when using the Noctua (2 to 4 degrees), so probably Noctua spinning ........
--- End quote ---

I have been trying to find SCPI commands for temperature measurement, but I can find nothing. So maybe I'm misunderstanding you, or I'm looking in the wrong place or I'm missing some documentation. The only thing I have been able to find is the STAT:QUES:TEMP command  to check for temperature errors/warnings. I used this when I did my fan conversion, but imo it was not very useful since no actual temperature values are specified. Neither could I find a SCPI  command to check the fan status. The RTB does monitor that the the fan is running and shows a prompt on the screen if the fan fails.
alonsojar:
Hi Rydda,


I found the scpi commands here in the forum...
https://www.eevblog.com/forum/testgear/rs-rtb2004-snooping/50/

To check fan speed I use
:SERV:MODE WEN;:SYST:FAN:SEN?

To check temperatures I've found two ways:

1.- SCPI command:
:SERV:MODE WEN;:SYST:TEMP:ALL?

The output for this command has many information, here is a sample

"1;CB-ADC0;5323 ms;64562.5 mV;0.000 mA;64.7 'C;93.2 %","2;CB-FPGA;5321 ms;180000.0 mV;0.000 mA;52.0 'C;90.7 %","3;CB-CPU;5323 ms;52687.5 mV;0.000 mA;52.7 'C;94.4 %","4;CB-TMP432;5323 ms;53687.5 mV;0.000 mA;53.7 'C;0.0 %"

Current temperatures for every sensor looks to be before the 'C.

2.- Another way is to generate a Service Report using the interface menu (Setup-> Device Information-> Service Report)
This will generate a serial.zip file in an external usb memory. Inside this file you can find a file named Deviceinfo.txt with information like this:

Temperature Sensors
1: CB-ADC0: 64.9 °C; Min 51.0; Max 65.4; Warning @ 95.0; Device Off @ 105.0
2: CB-FPGA: 53.0 °C; Min 47.0; Max 53.0; Warning @ 90.0; Device Off @ 100.0
3: CB-CPU: 53.7 °C; Min 50.6; Max 53.9; Warning @ 80.0; Device Off @ 90.0
4: CB-TMP432: 54.4 °C; Min 51.3; Max 54.6
Fan Speed = 95.2 %; Min 92.7; Max 95.3 (1823 rpm; Min 1320; Max 1833)


Hope this helps
J.Alonso
Rydda:

--- Quote from: alonsojar on August 07, 2023, 07:40:09 am ---
2.- Another way is to generate a Service Report using the interface menu (Setup-> Device Information-> Service Report) .........

--- End quote ---

Beautiful!!  Thank you!
I had seen the 'device information' menu item of course, but it did not seem interesting, so I just passed it by. 
I wonder how much else there is about this scope that I don't know . :-[

Just as a FYI, here are three excerpts (using my newfound knowledge) from the info utility. After one hour the temperatures are stable.
Four channels + sigGen active.
The ambient temperature is 26 C.
Note the fan speed! Ime fan speed is a very good indication of noise. As far as I can tell, the system never attempts to change the fan speed.

Operating time: 3 min
Temperature Sensors
1: CB-ADC0: 63.5 °C; Min 29.4; Max 63.5; Warning @ 95.0; Device Off @ 105.0
2: CB-FPGA: 55.0 °C; Min 22.0; Max 55.0; Warning @ 90.0; Device Off @ 100.0
3: CB-CPU: 42.5 °C; Min 24.1; Max 42.5; Warning @ 80.0; Device Off @ 90.0
4: CB-TMP432: 47.3 °C; Min 25.1; Max 47.3
Fan Speed = 91.8 %; Min 81.5; Max 91.8 (588 rpm; Min 452; Max 593)

Operating time: 1 h 1 min
Temperature Sensors
1: CB-ADC0: 69.2 °C; Min 29.4; Max 70.1; Warning @ 95.0; Device Off @ 105.0
2: CB-FPGA: 57.0 °C; Min 22.0; Max 63.0; Warning @ 90.0; Device Off @ 100.0
3: CB-CPU: 50.0 °C; Min 24.1; Max 50.9; Warning @ 80.0; Device Off @ 90.0
4: CB-TMP432: 52.9 °C; Min 25.1; Max 54.9
Fan Speed = 94.7 %; Min 81.5; Max 94.9 (598 rpm; Min 452; Max 609)

Operating time: 4 h 1 min
Temperature Sensors
1: CB-ADC0: 69.2 °C; Min 29.4; Max 70.1; Warning @ 95.0; Device Off @ 105.0
2: CB-FPGA: 59.0 °C; Min 22.0; Max 63.0; Warning @ 90.0; Device Off @ 100.0
3: CB-CPU: 50.6 °C; Min 24.1; Max 51.1; Warning @ 80.0; Device Off @ 90.0
4: CB-TMP432: 53.4 °C; Min 25.1; Max 54.9
Fan Speed = 94.7 %; Min 81.5; Max 94.9 (599 rpm; Min 452; Max 610)
alonsojar:
Mine after 1 hour. Room temperature 27 C (and rising :-\)
Same conditions, all analog channels and SG on. Of course stock fan.

Temperature Sensors
1: CB-ADC0: 64.5 °C; Min 28.6; Max 64.6; Warning @ 95.0; Device Off @ 105.0
2: CB-FPGA: 52.0 °C; Min 21.0; Max 52.0; Warning @ 90.0; Device Off @ 100.0
3: CB-CPU: 53.2 °C; Min 24.6; Max 53.2; Warning @ 80.0; Device Off @ 90.0
4: CB-TMP432: 53.8 °C; Min 25.9; Max 53.8
Fan Speed = 94.7 %; Min 81.2; Max 94.7 (1795 rpm; Min 1362; Max 1818)
 
J. Alonso
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