Data transfer cable upgrade?

[Nugs]

Hi all,

I'm controlling a AA269C by a Beelink GK mini (USB3).

Is it worth upgrading the supplied USB cable to a Lindy (or the likes)?

The supplied AA cable seems well made, and has a positive connection, but for a modest outlay of £12 for the Lindy CROMO, will i notice any tangible benefits?

TIA, Dave

[symmetal]

Hi Dave,

I found that the Lindy cables seem to have a firmer connection and require more efffort to plug and unplug, with less tendancy to move around compared to some generic cables, though this applied more to USB2 cables than USB3. If your current cable connection seems solid enough then there's no real need to 'upgrade'. The better cables have thicker wires for the two power pins compared to the data pins and more screening, so they are wider overall. Again this applied more to USB2 cables, than USB3  The various USB3 cable on Amazon etc. nowadays appear to have similar widths so electrically are likely very similar too.

Alan

[Skipper Billy]

I recently swapped the flat ribbon USB cable that came with an ASI178 for a Lindy Chromo and got an immediate 32% gain in max frame rate.

 

[Steve Ward]

51 minutes ago, Skipper Billy said:

I recently swapped the flat ribbon USB cable that came with an ASI178 for a Lindy Chromo and got an immediate 32% gain in max frame rate.

 

Thank you for that sir , just ordered a 5m version to help with my 174 ... 👍

[symmetal]

35 minutes ago, Skipper Billy said:

I recently swapped the flat ribbon USB cable that came with an ASI178 for a Lindy Chromo and got an immediate 32% gain in max frame rate.

 

I forgot to mention in my first reply that it's worth 'ungrading' if the supplied cable is too long for your setup. Having the PC on the scope I use 1m or 0.5m cables which as well as being more tidy, may also allow a higher frame rate for planetary imaging.

The Zwo flat ribbon cables are only available in 2m lengths and with their construction have lower screening compared to the usual round USB3 cables where the data pairs are screened separately, and then the overall cable has another thicker screen. It's tempting to coil up the excess length but this will likely increase crosstalk between the data wires due to the low screening, leading to reduced performance . Try to route the excess in such a way that it isn't in contact with itself or other cables for any significant length.

I did enquire from FLO whether Zwo could supply 1m cables but FLO replied that they had already asked this question to Zwo but they said no. 

I'm using the Zwo flat USB3 on my RASA 8 as it's easier to route from the front camera but as it won't be used for planetary any loss in the frame rate isn't too important. 🙂

Alan

[Nugs]

Out of interest, how would i work out the expected data transfer rate for the AA269? Generic cables seem to give up to 480Mbs, whereas the Lindy Black-line will go to 10Gbps.

[symmetal]

I think you're mixing up USB2 and USB3.

USB2 max rate = 480 Mb/s

USB3.0 max rate = 5 Gb/s

USB3.1 max rate = 10Gb/s

Your camera supports USB2 and USB3.0. Actually the USB3 interfaces have a USB2 interface built in so if you plug your camera cable which is USB3 into a USB2 port on your PC it will use the USB3's built in USB2 interface and give USB2 speeds.

Recent USB3 cables are made to USB3.1 spec so will support up to 10Gb/s though your camera will only work up to 5Gb/s. USB3.1 cables are fine being used as USB3.0.

As far as the maximum transfer speed you will actually get, these are usually significantly below the theoretical maximum. Using the Lindy cable you mentioned will give you the best chance at getting a fast speed. Get the shortest length USB3 cable you can get away with as that will improve your chances. Laptops and mini PCs are likely to give a lower speed than a desktop but you won't get a figure until you try it. 

My ASI178MM manages 30 f/s at max res of 3096 x 2080 while the ASI178MC manages 27 f/s with the GK Mini. Each frame is 3096 x 2080 x 8 bits which is 51.5Mb. At 30 f/s this is 1.5Gb/s and at 27 f/s this is 1.39Gb/s of image information.  There is an extra overhead for packing the data into the USB3 data blocks so likely around 2Gb/s actual data rate. Well below the 5Gb/s specified. 😉

Alan

 

[Nugs]

Cheers @symmetal, I find the TV remote confusing at times, so appreciate the detailed explanation.

 

[symmetal]

The AA269C specification gives typical framerates so any decent USB3 cable will work up to around 2m long. Longer than 2m, high quality cables like the Lindy would be preferable.

Quote

Approx. Max frame rates 8bit (assuming computer Bus operating at full bandwidth)*:

5280x3956    17.5fps    1x1 binning
2640x1978    17.5fps    2x2 binning
1760x1318    75fps    3x3 binning
584x440        210fps    9x9 binning

12bit mode:
Approx. 50% of above FPS.*

5280 x 3956 at 17.5 fps (8 bit) is an image data rate of 2.92 Gb/s

1760 x 1318 at 75 fps (8 bit) is 1.39 Gb/s

584 x 440 at 210 fps (8 bit) is 0.43 Gb/s

Alan