From: Milton Aupperle <maupperl@shaw.ca>
Date: November 6, 2012 12:00:29 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Re: ONAG Review
Hi Dave;
USB1 is 12 Mbps - known as "Full-Speed" - theoretical top rate of 1.5 megabytes per second.
USB2 is 480 Mbps - known as "Hi-Speed" - theoretical top rate of 60 megabytes per second.
USB3 is 5 Gbps - known as "Super Speed" - theoretical top rate of 640 megabytes per second.
However, a lot of the Astronomical cameras (like SBig, FLI etc.) are listed as USB2 but have slow download rates in the seconds per frame. For example, the LodeStar camera tops out at 10 fps (0.1 seconds per frame) download rate when in Binned 2x2 mode (376x290 pixels frame) and is a USB2 camera. That works out to about 1.04 megabytes per second.
A PGR FireFly MV USB2 camera runs as high as 60 fps @ 752x480 (21 megabytes per second) and when in binned ROI modes, could be as high as 224 fps at 160x120 sizes.
HTH..
Milton J. Aupperle
#1106 - 428 Chaparral Ravine View SE.
Calgary Alberta T2X 0N2
1-(403)-453-1624
maupperl@shaw.ca
www.members.shaw.ca/maupperl/
On 6-Nov-12, at 11:10 AM, Dave Goodyear wrote:
Arn't they just full speed 12mb/sec usb 2?
Dave Goodyear
Sent from my iPhone
On Nov 6, 2012, at 8:57 AM, "Milton Aupperle" <maupperl@shaw.ca> wrote:
Hi Dave;
Thanks for the information.
The other possible limit would be the cameras download rate. Most USB
2 Astro / Guide cameras are pretty slow at reading frames out tot he PC.
TTYL..
Milton Aupperle
On 6-Nov-12, at 1:25 AM, Dave Goodyear wrote:
Hi Milton.
I was able to get the AO up to 15.6 hz on a bright guide star using .
008 exposures. It seemed it wanted to go faster, i saw it go over
16 a few times.
Dave Goodyear
Sent from my iPhone
On Nov 3, 2012, at 12:35 PM, "Milton Aupperle" <maupperl@shaw.ca>
wrote:
Hi Dave;
Very cool.
Can you comment on how fast it can make corrections at using a fairly
bright Guide star?
TTYL..
Milton J. aupperle
On 3-Nov-12, at 1:28 PM, Dave Goodyear wrote:
I’m not going to get too involved with this discussion (:P ), but I
do have and use the SX AO-L all the time.
Dave Goodyear
KB2 Networks Inc.
214 Main St. #318
El Segundo, CA 90245
310-933-2436
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