Dell Compellent SC280 - what kind of serial console cable I need?

SC280 is a disk shelf without controller. So you cannot user serial cable to login. 

@tianchou​ thank you for replying! The SC280 has 2 SAS controller modules, as you can see for example here: https://www.ebay.com/itm/204601368218. From the photo you can see a "Console" port on the left side.
I understand that normally this enclosure is used connected to a Compellent Controller, but I am using it here as JBOD. 

i believe you need a special Dell ct109 / mn657 cable or it might be called del-ct109-bn-oe cable. connect that cable to usb to console cable to a laptop and then you can use Putty to connect to the box. baud rate should be 38400 if im not mistaken. Then once connected, the commands i think are _ver and _devils to see what you can do.  

@sc9000nerd​ thank you for replying! That cable works with the SAS controller from a SC200 (I also have this unit), but that controller has a different connector, like an old PS2 port. You can see that controller (for SC200) here: https://www.ebay.com/itm/256322037014
I believe that SC280 is part of the same family, but it does not have this connector, instead it has a 3.5mm jack port, labeled "Console". The SC200 port has no label, just a wrench icon.
The reason why I'm trying to access this is because I want to see if I can lower the speed of the fans. I can connect using the SAS port, and get quite a few details, but I don't know how to set the fan speed. I documented what I got so far here:
https://www.reddit.com/r/DataHoarder/comments/18x7pqm/dell_sc280_used_as_das_need_help_controlling_fans/ 

@Catalin7504​ ah my mistake if its the 3.5mm version you need i think it is 4R3WX for the PN. looking for cable with 3.5mm on one end and what would look like vga connector on the other end. DB9 to 3.5mm 4R3WX. you will also still need the usb to serial cable adapter as well (we use Sabrent).  I think that should be what you are looking for. 

@Catalin7504​ as for setting the fan speed i think that is something like

#>_shutup 20 

will set the fans to 20%

not sure if posting links here is allowed but 

https://forums.servethehome.com/index.php?threads/fun-with-an-md1200-md1220-sc200-sc220.27487/page-3

that might be useful resource

@sc9000nerd​ thank you for the update! I see that PN on ebay, will get one. I use a Dell R730 server that has a COM port. You are saying that I should use a usb to serial cable adapter as well, which makes sense since this PN 4R3WX has the serial connector like a vga connector (male type). 
I tried with a similar cable from Amazon, https://www.amazon.ca/dp/B06WLP4LTP?psc=1&ref=ppx_yo2ov_dt_b_product_details, but most likely the pinout is different, I got nothing using various combinations (speed, parity, flow control).

Thank you again, I'll buy that and will update here once I get it. 

@sc9000nerd​ I managed to connect. You are correct regarding the Dell cable, the PN should be 4R3WX or 5WD20. The Dell cable has a pinout as shown here:
https://forums.servethehome.com/index.php?threads/xyratex-sbb-enclosures-and-compatible-controllers.24160/post-388410
If you get a 3.5mm jack to serial cable from Amazon, use a multimeter and check the connectivity. In my case, I had to buy a RS232 Serial Null Modem Adapter (today for 12.42 CA$) but still cheaper than the Dell cable.

After connecting and pressing ENTER, I got access but the help command lists only this:

 
I assume that this enclosure does not support commands like _shutup or _set_speed. Maybe there is anything else I need to do first? 

@Catalin7504​ hmmmm you for sure tried _devils? if thats the case im not sure then. i dont currently have one of those controllers here to test myself. I will let you know if i think of anything else. 

@sc9000nerd​ Thank you for your help! I actually found more about this enclosure, and even if not successful in setting the fan speed lower, I will provide my findings, maybe it will help someone in the future.

The first thing was running help help. Crazy, I know...but guess what?

The GEM before the prompt seems to be abbreviation from "Generic Enclosure Management", as I could find here. 

So, running help all, brings a whole new list of commands. From this list, I see a fan_set command that looks promising. 

Ok, so running help fan_set shows that this command accepts a speed parameter. Even more promising. Searching online by fan_set I found a HPE article that refers to Cray ClusterStor, subsection named "Replacing a 5U84 fan module" so I thought this is similar enclosure. There are two notes in this article: 

- Fans 0 and 1 refer to fan module 1, fans 2 and 3 refer to fan module 2, and so on.

- Speeds in the 13K-14K range indicate a potential problem. The 8K range is typical.

Next, I run fan_set with results below. 

 
As you can see, the fans are in the 8K range, as indicated in the article. Next step was to set a lower speed, and I used fan_set 0,1 speed 6000. This did not work, the fan speed remained the same. Replacing 6000 with anything greater than 8000 will work, the fans will increase the speed. Also, if you try to set the speed of only one fan from a fan module (example fan_set 0 speed 9500) will result in all fans going crazy in the 13k-14k. I assume the software consider that it's a fault that inside the same fan module one fan runs 9500 and another one 8k, and all fans go full speed. You can revert this by running fan_set normal.

Sorry for the long post. Right now I am out of ideas, how to set the fan speed lower. The only other thing I can think of is looking into gncli command, who's description says "Run CLI command on remove GMNET node"
Also, just before submitting the post I noticed another command listed below. It seems that if I can figure how to set the minimum speed for the fan, I might be able to set it lower. Maybe ...

@Catalin7504​ wow that is great find and source of information EXECLLENT JOB. thank you! Not sure if this may help but i know on like my r730xd in order to lower the fans there were a couple of settings. one i had to switch the fans to manual control, from there i could lower them. the other thing was that i think they normally run off profiles or percentages. maybe digging around in that menu you might find something to change profile or set to manual control?  

@sc9000nerd​ I have this SC280 connected to a R730xd as well. You are correct, there are options in iDrac to control the fan speed, but the SC280 enclosure seems to be different. Anyway, I am still looking into this, if I find something I will update here.
Another thing I want to mention is that I can use sg3_utils (sg_ses tools) to get info about the enclosure, fans, drives, etc. That does not require the terminal connection, which is fine, but still did not figure out how to go lower than 8k fan speed. However, I might look into creating a simple Windows app to provide info about the enclosure, drives, etc.