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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5610576 - 01/07/13 04:55 PM

Quote:

Mitch,

Can you run a benchmark speed test on your device? If you stick a USB flash drive on one of the USB ports and roll out 100ft of cat5 cable then try this little program and run the speed test.

--> http://www.steelbytes.com/?mid=20

I have used this to test the speed of my 5m repeater cables and my USB 1.1 dongle over 100ft of cat5. For my purposes, to get video from my capture device back to the computer, e USB 1.1 fails. Then again, measuring the speed of my USB ports on the computer and out on 45 ft of repeater cable plus a powered hub was almost the same. I think if you test the speed of your device over the 100ft distance and then compare it to what speed you achieve on the flash drive plugged directly into the PC USB port it would be very helpful.

Al





Al,
My initial response last night to your suggestion was that I didn't have a flash drive and that with the New England winter weather would not allow me to run out a 100 ft length of cable due to the snow/ice sloppy mix we have on the ground at the moment...

However, over the course of the evening, I kept thinking about your suggestion, remembered that I have a Western Digital 1TB Passport USB3.0 drive for which I have a 3 ft USB3.0 to USB2.0 cable.

I downloaded the HDspeedtest utility you supplied the link for. This afternoon I dug out a new 100 ft. roll of Cat-5e cable, pulled a couple feet of each end out of the coil leaving the rest in the tight as shipped coil...

Note that all tests are READ tests only as write tests wipe out all data on the drive and my interest is primarily in downloading 20-30 Mb RAW data files from the DSLR. All tests are made using the 3 ft. USB3.0 to USB2.0 conversion cable for USB2.0 port compatibility in all tests.. Each test was run with elapsed time set to 3:00 minutes.

I ran several tests, first test was the Passport USB drive plugged directly into a USB2.0 port on a HP DV6T Laptop.
Average read speed with 32Kb block = 20.1M byte.sec.
Average read speed with 256Kb block = 26.1M byte/sec.

Note for the following tests, the USBgear 4 port USB/IP hub is plugged into a NetGear 10-100-1000 gigbit Switch which in turn is plugged into the same HP DV6T Laptop using a 6 foot Cat-5E cable, the DV6T has an internal 10-100-1000 Gigbit Ethernet adapter. Normally there is other gear plugged into the Switch however all was unplugged for these tests so that only the USBgear USB/IP Hub wss on the Ethernet network... As my normal method of remote operation is by a Cat-5 cable plugged into the switch, I wanted it part of all tests...


Next, with the USBgear 4 port USB/IP hub plugged into a Netgear 10-100-1000 Gigbit Ethernet switch using a 10 ft Cat-5e cable, I ran the following test:
Average read speed with 32Kb block = 10.0M byte.sec.

I changed the USBgear USB/IP hub to Switch Cat-5 cable to the coiled 100 ft. cable and ran this test:
Average read speed with 32Kb block = 10.8M byte.sec.

A bit of learning in the process of running these tests led me to believe switching to a larger block size gave better speeds so after a bit of experimentation to find the optimum block size, I switched to 256Kb blocks and ran the following tests.

Passport HD plugged into Laptop USB port:
Average read speed with 256Kb block = 26.1M byte.sec.

Passport plugged into USBgear USB/IP hub plugged into switch with 100 ft Cat-5e cable:
Average read speed with 256Kb block = 14.4M byte.sec.

On occasion, while using the 100 ft. Cat-5e cable, there were strings of blocks of data that ran for several seconds at 17M byre/sec.

Most interesting to me was that the speed was better over the 100 ft Cat-5e cable as compared to the 10 ft Cat-5e cable. My only thought is the cables were purchased as pre made cables on Amazon.com at different times and came from different Amazon distributors and probably are of different quality... There is also a possibility of SWR reflections being affected by the different lengths of the cables however that is a subject beyond the scope of this evaluation. Interestingly, no data errors were reported during timed test runs.

To me, that the USBgear 4 port USB/IP Hub performed well over the 100 ft cable combined with the NetGear Ethernet switch is adequate to convince me the use of USB over TCPIP networking should be a major step to better remote control of an imaging system...

As a point of information, USBgear appears to be a brand name of www.CoolGear.com. There is a third name that comes up in the CD documentation that comes with the unit, "Elite Silicon Technology" but no information as to who the actual manufacture is...

The unit seems to be well made and has worked reliably and well in all my tests and experimentation so far...

Edited by fmhill (01/07/13 05:04 PM)


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CJK
professor emeritus


Reged: 12/05/12

Loc: Northeast TN
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5611415 - 01/08/13 06:55 AM

Just announced at CES: Corning optical USB & Thunderbolt cables

Possibly another option.

-- Chris


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: CJK]
      #5611567 - 01/08/13 09:18 AM

Quote:

Just announced at CES: Corning optical USB & Thunderbolt cables

Possibly another option.

-- Chris




Hi Chris,

Thank you for posting that exciting information. I have bookmarked the page for future reference...

I have to explain why that info is exciting to me, I am a retired Oceanographic equipment designer and about 25 years ago, the company I worked for switched to using Corning Fiber Optic technology for cables to carry trigger pulses to high energy acoustic sound generation equipment.

The use of Fiber optic cables eliminated electrical interference noise problems and greatly reduced propagation delays as well as allowed long cable runs of high reliability...

At that time, we were purchasing spools of fiber optic cable, a very flexible black cable about 1/8" to 3/16" diameter and connector kits and making cables up to what ever length we needed. The connectors looked like a Cable TV "F" connector which was glued onto the fiber optic cable using a high optical transparency epoxy... Simple and very effective...

As a result, to read that Corning has developed a fiber optic USB cable system is very exciting news indeed...

Fiber Optic USB cables might well be the ultimate solution to remote control imaging where the control & processing equipment is remote from the imaging equipment provided they are within cable reach of each other...


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microstar
Pooh-Bah


Reged: 01/05/08

Loc: Canada
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5611679 - 01/08/13 10:31 AM

I use this product to simulaneously control and collect data from mount, CCD, DSLR, QHY5 guidecam, and ancillary equipment via a single Cat5 cable to my backyard observatory. Works great.

http://www.icron.com/products/icron-brand/usb-extenders/cat5/usb-2-0-ranger-2...

...Keith


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Raginar
Post Laureate
*****

Reged: 10/19/10

Loc: Rapid CIty, SD
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5612177 - 01/08/13 03:31 PM

I tried this box you mentioned (http://www.usbgear.com/USBG-4NET.html) with my setup at that time (Orion Star Shoot 3 mono / QHY or Starshoot guider) and had no success connecting through their software. I tried two of them before I got an RMA just asking for my refund.

I'm glad you got it working; it did not work for me. One other thing of note was it definitely didn't recognize a usb hub attached to it and 4 USB plugs was not enough for my setup.

Personally, having a computer attached is the easiest solution I've found. Then, VNC into your computer. In addition, if you need to troubleshoot connectivity or focusers, you have a computer 'right there' to do so.

Good luck,


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ccs_hello
Postmaster
*****

Reged: 07/03/04

Re: Long-run USB alternative idea - router new [Re: Raginar]
      #5612521 - 01/08/13 06:55 PM

Quote:

... Orion Star Shoot 3 mono / QHY ...



At least I know these two are using the "double boot" method which is tough to emulate. Many astroimager use streaming in high-speed isochronous transfer mode which is also hard.

Elite Silcon (E3868)'s method just need one box on the USB device end due to its "USB over IP" strategy, while icron needs two (one on device end and the other on PC end) which is using "USB over proprietary" method.

In both cases, there is a short cut: bypassing two-way handashake (which is the reason why the USB max. distance is limited) and just "transmit in blind".
In plain English, say a supplier kept sending bags of concrete to a build site. At some point, the project manager in the build site will have to say, stop (or slow down) I am too busy here. Or he might have to tell the sender that a specific bag has defect material and please resend that one. Regular USB with two-way handshake can do that. The work around method simply doesn't care and claims the world peace achieved.
Will latter work all the time? Luck will tell .

P.S. recent refurb Core 2 Duo laptops (many formerly business grade) can be obtained for less than $200, Win XP Pro included.

Clear Skies!

ccs_hello


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microstar
Pooh-Bah


Reged: 01/05/08

Loc: Canada
Re: Long-run USB alternative idea - router new [Re: ccs_hello]
      #5612624 - 01/08/13 08:02 PM

As I said, the ICRON Ranger 2104 (now replaced by the 2204) USB over Cat5 has no problem with collecting data from a dual imaging rig with an Atik 383L+ mono CCD and Canon XSi while at the same time guiding with a QHY5 webcam and PHD and controlling the mount, focuser and sky monitor. I know when I told the QHY5 distributor here in Canada that I was doing this over a single Cat5 cable he was surprised. It costs a little more (but look around, I saw one Canadian distributor clearing them out at a discount) but it works with high-speed isochronous transfer and multiple devices simultaneously. Although some things didn't like being connected via the hub attached to the 2104 and needed to be connected directly to the unit, other than having to play with the arrangement it has worked pretty flawlessly for me.
...Keith


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Raginar
Post Laureate
*****

Reged: 10/19/10

Loc: Rapid CIty, SD
Re: Long-run USB alternative idea - router new [Re: microstar]
      #5612776 - 01/08/13 09:46 PM

Oh, I didn't say that this was with 100' of Cat6 cable as well.

My only issue with all of these devices is the lack of troubleshooting capability at the telescope. For instance, some times you want to be right there to test things or figure out why your filter wheel/focuser is on the fritz. Using one of these requires you to run back n forth or utilize a tablet...

I'll stick to a cheap computer at the 'scope.


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Charlie B
scholastic sledgehammer


Reged: 03/22/08

Loc: Sterling, Virginia
Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5614135 - 01/09/13 05:31 PM

Quote:

such as leaving a laptop there and VNC'ing into it from the desktop



This is the method I use. I got a new laptop for Christmas and now my old one is available for remote control. I use UltraVNC and it works perfectly through my wireless router. I've connected up to 300 feet with good signal.

I still use a USB hub to the remote computer, but only need a single cable. The hub has the advantage of being able to easily route camera/filter/focuser cables close to the cg of the mount with not a lot of long cables to the computer. I could even mount the hub on the ota.

Regards,

Charlie B
Regards,

Charlie B


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5614353 - 01/09/13 07:30 PM

Part 2 /Day 2 continuation of evaluation of remote control/data transfer for imaging...

To see how the results of the speed tests using the USBgear 4 USB port ethernet hub over a 100 ft Cat-5E cable that I reported in my post above compared to the USB/WiFi 4 port hub and to the Tether Pro Active USB cables that I have been using very satisfactorily for the past 3 years, I accomplished several more tests this afternoon.

The conditions and parameters for these tests are the same as for the tests yesterday, the same HP DV6T laptop was used with the same HDspeed test software, only the communications protocol was changed along with the necessary communications devices.

The first test this afternoon was to see how well the IOgear 4 port USB over WiFi hub performed...

The communications path is from a wireless-N adapter built into the HP Laptop to a Verizon Jetpack 4G/Wireless-N router (part of my inhouse wireless network) to the IOgear USB/WiFi 4 port hub. Distances = 4 ft from Laptop to WiFi router, 8 feet from WiFi router to USB/WiFi 4 port hub so RF signal levels were not a limiting factor.

Using the same Passport HD USB3.0 1TB drive with the 3 ft USB3.0 to USB2.0 adapter cable, READ tests of 3 minute elapsed time resulted in 64 Kb block size being optimum and best speed reached was 1.1M bytes/sec.

I then decided to make a comparison of the tests results run so far to the Tether Pro Active USB extension cables tested in the same configuration as I use them when imaging...

My first test of a Tether Pro cable was to attempt to access the Passport USB drive plugged into a 15 meter Tether Pro cable plugged directly into a USB2.0 port on the laptop. No hub, just the drive on one end of the cable and the other cable end plugged directly into the Laptop.

Nothing, the light on the drive came on but the computer refused to recognize the drive...

That had me puzzled for a moment, then I realized that the Passport being a 1TB USB3.o drive probably draws more current than the extension cable being USB2.0 can deliver considering the length of the cable has to also power the repeater modules. At that point I put the USBgear 4 port USB2.0 externally powered hub on the far end of the Tether Pro USB extension cable and plugged the Passport drive into the hub. ((Note that the USBgear 4 port hub also has a USB link port making it usable as either TCPIP or USB linked hub).

Instant success... And not surprisingly, the HDspeed test utility showed nearly the same rate as the Passport drive plugged directly into the laptop with the 3 ft cable. Read time for elapsed 3 minute test over the 15 meter Tether Pro cable was 25.4M byte/sec.

At that point I added another 7.75 meter Tether Pro cable in series with the 15 meter cable for a total of 22.75 meters and speed dropped very slightly to 25.1M bytes/sec.

I decided to see what would happen if I added my other 7.75 Meter Tether Pro USB cable for a total of 30.5 meters which exceeds the allowable useable length according to the Tether Pro documentation which states the usable limit is 25 meters... Windows immediately produced an error message stating number of USB repeaters = 5 exceeds allowable limit. (apparently the hub is counted as a repeater as well)...

So the concept of adding more Active USB repeater cables even if reduced performance is acceptable is not possible... It would seem the 25 meter limit as stated is the functional limit with no exception...

After two days of testing various link communications methods and protocols, the conclusion is:

Passport 1TB USB HD plugged into Laptop = 26.1M bytes/sec.

25 meters or less, Active USB cables = 25M-26M bytes/sec.

Over 25 Meters with USB/IP hub = 14M-15M bytes/sec.

WiFi - (not distance tested) = 1.1M bytes/second.

Note, the actual speeds reported may vary with equipment used. The importance here is that for all tests I have run I have used the same Laptop and the same USB HD and the same HDspeed test software to keep the results standardized. The speeds as I report are in no way indicative of actual product specifications, this is purely a series of comparison tests...

That is the end of these tests as far as I am concerned, my conclusion is that WiFi is not suitable for combined mount control, imaging data flow, and Guiding camera data all combined on one WiFi link using a 4 port USB2.0/WiFi hub.

As to USB extension cables vs USB/IP, more testing when the weather improves to see how each protocol performs dynamically with full imaging operation and/or need for length beyond the 25 meter limit of USB will be the deciding factor...

Edited by fmhill (01/09/13 07:39 PM)


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A. Viegas
scholastic sledgehammer
*****

Reged: 03/05/12

Loc: New York City/ CT
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5614637 - 01/09/13 10:44 PM

great work Mitch. Looks like a string of USB repeater cables is hard to beat unless you need to go much more than 100ft. (especially when you consider cost!).

Al


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ccs_hello
Postmaster
*****

Reged: 07/03/04

Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5614657 - 01/09/13 10:53 PM

USB repeater by the book method, see this CN thread.

Clear Skies!

ccs_hello


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5614730 - 01/09/13 11:56 PM

Quote:

great work Mitch. Looks like a string of USB repeater cables is hard to beat unless you need to go much more than 100ft. (especially when you consider cost!).

Al





Hi Al,

Yes, these tests turned out to surprise me more than I was expecting. I had not expected the Tether Pro cables to perform as well as they do, I was expecting more loss at 15 - 25 meters than I found with them. They are virtually lossless for all practical purposes...

And I was expecting the TCPIP link to blow the sox of the USB cables as far as speed is concerned which it did not, another disappointing result...

However, I do think the TCPIP performed well considering there was very little change by adding a 100 ft. cable. In hind sight, thinking about this TCPIP Ethernet link test afterwards, there is one more test I should run, and that is to link another 100 ft cable making the length 200 ft...

I have several of the 100 ft Cat-5e made up cables and an additional 50 ft. cable. I have three RJ-45 couplers so it would be a simple test to expand the results to include test results with a longer run of Cat-5e cable...

However, in my own setup, I do not need more than 100 ft. maximum. I'm working with 15 meter USB cables which are plenty long enough... So, whether I actually will be inspired to run several hundred feet of cable out is an unknown, I'll have to think about it for a bit... I have yet to re-coil the 100 ft Cat-5e cable I have strung around the place now, so maybe tomorrow I'll get inspired...

There was another comparison result that came about in this testing that I did not bother to write up. I have a IOgear 4 port USB/IP hub, a retail consumer grade loaned on trial, and I did not consider it to be a contender. As like most IOgear, its a really cheap design and the specifications are very vague however its labeled and sold as a USB2.0 complaint device. Therefore I did plug it in and configure it for the network however the most I could get out of it was 3.7M bytes/sec. using a 10 ft. CaT-5 cable...

Fortunately, I don't own this one, its going back where it came from as soon as I can get it packaged up and shipped out...

Just the same, it was interesting to have a second USB/IP hub here to compare to the USBgear USB/IP unit...

The biggest disappointment was the USB over WiFi test although I was expecting that result, just not as bad speed wise as it turned out to be, I'd hoped to get somewhere about 4M - 5M bytes/sec. however again, the manufacturers specifications were misleading, it turned out to be a 802.3g device, not wireles-N, the difference being 802.3g is a single band simplex protocol as compared to the current technology wireless-N being multiband full duplex capable...

So, if I can find the right gear, the USB over WiFi test may be retested when time allows... Probably a project for next winter...


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5614810 - 01/10/13 01:26 AM

Well, a quick answer to USB over TCPIP on Cat-5E cables longer than 100 feet, a quick test plugging two 100 Ft. cables together doesn't work... It looks to be too much length for the 10-100-1000 Gigbit network. The Laptop knows something is plugged in but is unable to communicate. Looks like the Ethernet router Switch indicator lights are showing a 10base-T speed connection with 200 ft of cable where as with a single 100 ft. Cat-5 cable, it indicates high speed with both indicators lit... This could be the result of a poor quality or faulty cable as one of the two is one I've had for a while and all other tests were done with a brand new cable...

However, using a 6 ft Cat-5e patch cable to avoid unrolling the older 100ft. Cat-5e cable allows a test of the second cable and the coupler plugged into the Ethernet switch to Laptop and the coupler old cable combination tests OK...

Apparently the limiting factor is network speed/signal strength over more than 100 ft. of Cat-5E cable. As what I am using is inexpensive cable ($12.95/100 ft.) purchased on Amazon.com, possibly there is a better quality of network cable that might extend the range...

Edited by fmhill (01/10/13 01:30 AM)


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: tjugo]
      #5621311 - 01/13/13 05:40 PM

Over the weekend, thanks to foggy/rainy weather, I had time for follow up testing in my process of deciding what is the most efficient protocol and equipment for remote control/data collection of my imaging setup.

In spite of the initial results showing that Tether Pro Active USB extension cables at 25M bytes/second at maximum tested length of 25 meters being the clear winner, my second choice being a USBgear 4 port USB/IP hub being the second most efficient method at 15M bytes/second over 110 feet of Cat-5e cable (100 ft to router plus 10 ft to the laptop from router), I decided the next test would be to see how well the USBgear hub over the 100 ft Cat 5 cable would be affected by multiple active Devices...

I also wanted to evaluate which of the two cameras would load the network the heaviest, the Canon 60Da or the Orion SSAG guiding camera. This is a test prompted by a post by Guylain Rochon that he has found the SSAG camera to be the heaviest load on communications in his setup.

To this end I plugged the USBgear 4 port USB/IP hub into my Ethernet router, plugged the Canon 60Da, the Orion SSAG autoguider, and the Passport HD into the USB hub.

With all three USB devices active, I started PHD, connected the autoguider camera pointed at a bright light to saturate the sensor, and started BYEOS live view connected to the Canon 60Da. I then started HDspeed test to monitor efficiency/speed of 256Kb block size continuous reads of the HD as an indicator of network load...

Interestingly, the combined effect of all three USB devices in operation simultaneously showed about a 10% drop in read speed of the HD.

To determine which USB device was the cause of the heaviest network load, I alternately disconnected the Orion SSAG and the Canon 60Da and while each was operating independently, tried various exposure rates.

The end result was as Guylain reports, the Orion SSAG caused the read rate of the HD to drop about 10% while the 60Da in either live view or imaging mode caused only a slight drop of a percent or two worse case. To my surprise, the 60Da active in Live View mode had little effect as far as network loading as indicated by read speed of the HD...

My conclusion is that if I continue to use USB active extension cables in the future, I will plug the SSAG camera into the dedicated cable and the 60Da into the USB hub which is the reverse of my previous setups.

I'm also reasonably convinced that USB over the TCPIP Ethernet link is adequate to handle the multiple USB inputs, that the 10% reduction in speed is virtually transparent to the practical operation of the cameras based by observing the live view of the Canon 60Da while the SSAG is running in saturated mode at various exposure rates also tested by making 5 test exposure with BYEOS in imaging mode transferring 20M RAW image files to the laptop over the link. A few instantaneous speed reduction spikes were observed in the HDspeed test graph however the reported speed average did not change...

Moving on...

After a night to think about the poor performance of the USB/WiFi link at 1.1M bytes/sec., as I am still very much interested in this method, I decided another test was worth conducting. This test to be using a WiFi link between the HP DV6T laptop with internal Wireless-N adapter using protocol to my inhouse i7 CPU quipped PC which has a Intel Wireless-N network adapter installed. The connection is through the Verizon 4G/Wireless-N router which is how my inhouse wireless network normally routes between the Laptop and the PC.

However, what I found was that the HDspeed test utility will not recognize the USB Passport HD over the link through the second PC via the wireless link. I believe this is because a USB hub uses USB repeater protocols and a PC does not, therefore the HSspeed test utility can not see the Passport HD through the PC as it does when using the USBgear USB/IP hub...

However, as one phase of my original testing of the 4 port USB/WiFi hub was a visible test of the 60Da in live view mode, the result being a lot of delay and dropped frames, I decided to test the WiFi link between the two computers using Win 7 remote desktop function and repeating the 60Ds Live View mode. Again, there was an increased visible delay but no obvious dropped frames that I could see... Using a true Wireless-N WiFi link does seem to demonstrate improved performance over the original WiFi test however is still noticeably slower than either the USB/IP Ethernet link or the use of Active USB extension cables.

My interpretation of the result of this crude live view comparison test using Win 7 RD shows that the link between the two PC's being a true wireless-N format as compared to the 4 port USB/WiFi hub being Wireless-G protocol hub. However, simply by switching between the two PC's shows the WiFi Wireless-N link is still considerably slower than the TCPIP Ethernet link...

AT this point, I am satisfied that the Tether Pro Active USB cables will continued to be used in my remote installation imaging setup however I also plan to continue testing and evaluation of the USB over TCPIP link as I believe it has adequate efficiency/speed and my guess at the moment has enough benefits with adequate performance to equal the active USB extension cable when in actual use when imaging... In part this is that I believe when used for actual imaging, the load on the link is not as continuous or as heavy as what I have generated for testing purposes...

Edited by fmhill (01/13/13 06:06 PM)


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A. Viegas
scholastic sledgehammer
*****

Reged: 03/05/12

Loc: New York City/ CT
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5621357 - 01/13/13 06:05 PM

Mitch, thanks for the analysis. Certainly suggests to me that using a long USB repeater chain is the preferred method. One question I still have, I think it was ccs_hello who said that there was a limit on the number of USB repeater hubs you can have. Is this a limit just for XP? Can windows 7 handle more than that? I also think he said a 7 port hub counts as two repeaters? So how can you get to 25m using the tether pro cables? That would suggest 5 5m repeaters plus your hub... Hopefully the answer is that there is in fact no limit on e USB repeater chain?

I also have a 100ft cat5 and USB dongle set, but I only use that for low speed devices like GPUSB ST4 box and USB to serial for planetarium or nexRemote. Interesting I tested plugging in is 100ft USB 1.1 into my USB 2.0 hub and testing the speed on three 5m repeater cables. Funny enough I clocked consistent 992kbps on the USB 1.1 irrespective of where it was plugged in. However the USB 2.0 repeater cables averaged 19Mbps to 23Mbps depending on which port I used on e hub. When I did not use the slower USB 1.1 plugged into the same hub, I achieved closer to 24Mbps, but only on one of the 4port hub connectors.

Net, net my setup is probably just going to continue as it... I ordered another 2 5M repeater hub cables, so I will have 5 segments and two hubs, one hub after 2 segments and another hub at e end of segment 5. I will drive two telescopes and 3 cameras. Let's see how it goes,

Al


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5621439 - 01/13/13 06:54 PM

Quote:

Mitch, thanks for the analysis. Certainly suggests to me that using a long USB repeater chain is the preferred method. One question I still have, I think it was ccs_hello who said that there was a limit on the number of USB repeater hubs you can have. Is this a limit just for XP? Can windows 7 handle more than that? I also think he said a 7 port hub counts as two repeaters? So how can you get to 25m using the tether pro cables? That would suggest 5 5m repeaters plus your hub... Hopefully the answer is that there is in fact no limit on e USB repeater chain?

I also have a 100ft cat5 and USB dongle set, but I only use that for low speed devices like GPUSB ST4 box and USB to serial for planetarium or nexRemote. Interesting I tested plugging in is 100ft USB 1.1 into my USB 2.0 hub and testing the speed on three 5m repeater cables. Funny enough I clocked consistent 992kbps on the USB 1.1 irrespective of where it was plugged in. However the USB 2.0 repeater cables averaged 19Mbps to 23Mbps depending on which port I used on e hub. When I did not use the slower USB 1.1 plugged into the same hub, I achieved closer to 24Mbps, but only on one of the 4port hub connectors.

Net, net my setup is probably just going to continue as it... I ordered another 2 5M repeater hub cables, so I will have 5 segments and two hubs, one hub after 2 segments and another hub at e end of segment 5. I will drive two telescopes and 3 cameras. Let's see how it goes,

Al




Hi Al,

The limit of repeaters in linked USB cables is a function of the USB protocol I believe, it is not dependent on the Windows operating system as far as I know. I have run into that here with the Windows 7 Pro 64 bit operating system on both of my computers. I believe I reported on that in one of my previous posts.

However in my testing, I have used a passive 10 ft USB extension cable plus a 9 ft USB device cable on the far end of daisy chained Active USB cables to the hub meaning I was testing with 25 meters of cable with 3 repeaters plus 6 meters of passive cable with a 4 port USB hub at 31 meters total. This seems to work as long as the active USB cables are closest to the computer. It would seem, at least in my testing, that a total of 4 repeater IC's is the maximum allowed.

As to a 8 port hub having two repeaters internally, I can not confirm this, I do have a 7 port IOgear USB hub that has proven not to work correctly however I have never seen the error message when using it that it has exceeded the allowable number of repeaters. My opinion is that the 7 port USB HUB is simply another piece of IOgear cheap junk... I've been burnt 3 times with IOgear junk, I will never purchase an IOgear product again...

BTW, for what it is worth, in my previous report/posts, I referred to using 7.75 meter and 15 Meter Tether Pro Cables, that was an error on my part, the 7.75 meter cables are actually 9.75 meter cables... I happened to be looking on the Tether Tools site this afternoon and realized my mistake.
http://www.shop.tethertools.com/TetherPro-USB-20-Active-Extension-Cable-16-32...

As to daisy chaining 5 meter USB cables, I think you will be limited to 3 active cables plus a passive cable, and a hub maximum based on my experiments however i do not know anything about what cables you are using...

What I post about is based on what I have done myself and know works which means I could be wrong about what you discover in your setup...


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5621487 - 01/13/13 07:26 PM

Al,

I meant to comment in my previous post, I have a couple sets of the USB to Cat-5 adapter dongles on 100 ft Cat 5 cables and they do work however at slower speed than the Active USB extension cables.

I have not attempted to do a benchmark speed test on them as I've had them for a while and since switching to the active USB extension cables, I've simply not had a need to use them...

That would be a simple test to run, You've piqued my curiosity, think I'll give that a try just to see where they fit in the scheme of link efficiency...


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A. Viegas
scholastic sledgehammer
*****

Reged: 03/05/12

Loc: New York City/ CT
Re: Long-run USB alternative idea - router new [Re: fmhill]
      #5621556 - 01/13/13 08:11 PM

Mitch,

I currently use 2 über cheapo 5m USB repeater cables and two 10ft passive cables with a powered 4port and a powered 7 port hub. I need another 20 to 30 feet to add my second telescope this spring. My setup will look like this I am thinking:

PC in study.
--> 5m repeater and 10ft passive to 4 port hub
-->. USB 1.1 cat5 100ft running out to Scope 2 ( future plan)
-->. 5m repeater
-->. 5m repeater to 4 port hub
Scope 1. --> scope control, autoguider and USB 2.0 camera
--> 10 ft passive
-->. 5m repeater
--> 10 ft passive
Scope 2.
USB 2.0 compliant camera
USB 1.1 to scope control


Right now I have this setup to scope 1 wi no issues,

Al


P.S. my super cheapo USB repeaters are:
http://www.amazon.com/eForCity-ACTIVE-EXTENSION-REPEATER-CABLE/dp/B004I1E6MU/...


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fmhill
sage


Reged: 07/17/12

Loc: Cape Cod, Massachusetts, USA
Re: Long-run USB alternative idea - router new [Re: A. Viegas]
      #5621683 - 01/13/13 09:05 PM

Hi Al,

Interesting setup... Hey, if the el cheapo repeater cables work for you, your in business... I was surprised to see the price as low as it is... That is a significant factor...

If it ain't broke, don't fix it!!!

A fellow on another forum posted a Amazon link to
"Alfa USB 2.0 Active Extension Cable - Repeater Cable - High Speed 480Mbps - A Male to A Female - 15 Meters / 49.2 feet Long"

He is apparently using these cables and likes them... I have bookmarked this cable for future use if I decide I need more than what I have on hand.

Alfa USB Active USb2.0 Extension cable


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