Chromatography Forum

colleagues,

two questions:

1. do you have any hints why Waters and Agilent (thoughtfully designed chromatographic systems) use Ethernet interface to communicate to a PC, while Thermo Dionex LC system e.g. Ultimate 3000 (and Accela in the past) still uses awkward USB interface. It means that maximal distance between the PC and LC is limited to 5 meters.

2. how do you solve this issue (if you have it) when you need to have an USB-controlled device at a distance significantly greater than 5 m? We have quite a lot of instruments located at the specially air conditioned area, and the computers are too far! Dionex makes me mad.

you need an active usb cable like this from belkin http://www.belkin.com/us/p/P-F3U130/ . Google it and you will fin many more

yes, but such cables have 25 m maximal length, which is less than I need..
thanks anyway

There are also special USB to Lan converters that work..

leadazide,

point me please.

I have bought this unit http://www.vscom.de/413.htm which seemed to be a perfect solution but in practice this converter has to recognize the type of the USB device you plug into it (memory stick, printer, scanner etc).
With the Dionex it did not work...

carlo,

yes, this is how my system works now, but it hangs once a day at least (connection to LC is lost), which I cannot accept

that is why I am asking for the already implemented solutions, not just theoretical possibilities

I have a customer using a BlackBox product.. The information on the back of the box says

Serverswitch Wizard
USB Extender
PartNO: ACU5050A - Remote

I know he is running two Ultimate system via these boxes at ranges of more than 15 M..

leadazide,

thank you. I have also googled that it is possible to have a Linux machine to which USB devices are connected and the software then redirects the USB signals via local area network to the PCs with client software installed
http://www.incentivespro.com/usb-server.html

anyway I think Dionex engineers should spend some efforts and finally start manufacturing the instruments with Ethernet interface. This would make the life of their customers easier.

leadazide,

anyway I think Dionex engineers should spend some efforts and finally start manufacturing the instruments with Ethernet interface. This would make the life of their customers easier.

I agree and disagree.. 90% of all problems I run into at customer sites are communication related and always on systems running on LAN.. USB never an issue! Therefore I love the USB connected instruments! But I agree with the distance limitation sometimes being an issue..

I agree and disagree.. 90% of all problems I run into at customer sites are communication related and always on systems running on LAN.. USB never an issue! Therefore I love the USB connected instruments! But I agree with the distance limitation sometimes being an issue..

I agree entirely. I have never observed problems with the usb connections on my Dionex system but frequently problems with ethernet (or HP-pib prefered long time by waters) connections.

For a comparable enviroment I use an additional computer as dedicated instrument control client with usb connection to the instrument.

Hi Trozen,

As I think Klaus has suggested above, keep the IPC connected to the instrument via the USB but then network to a remote client via LAN. This will then let you control the instrument from anywhere within your domain.

There may be some additional license requirements for the remote client, but it's probably the most straight forward and commonly used set up.

Hi Trozen,

I believe the theory is that you actually have a higher consistent bandwidth with USB than you do with 10baseT Ethernet. Now that's obviously changed since the standards and hardware for Ethernet have advanced, but your original question was why the Dionex instruments used USB initially.

-Mark

I'm not sure about the actual gigabit-ethernet or USB-3 protocols, since the concrete composition of the exact chip-set have the biggest influence. But in terms of the actually used chromatography systems: USB-2 is surely faster than the still wide-used 100base ethernet. However it would be from interest, when this infrastructure is used at full capacity.

Hi,
I love the USB interface and it is a reason to select Dionex instead of Agilent and Waters! I have had and has far too often problems with instruments using LAN. It is a major advantage not to have to patch/upgrade/replace black boxes using Windows XP that Empower and EZChrom are using in regulated environments. And keep all non-touchable black boxes in secured updated mode - how do you actually solve that riddle? At least Chemstation is not using black boxes.

(As pointed out above - you can always use remote connections and if you want to, even control the instrument from your vacation spot. But I have never understood how anyone can have the instrument PC more than 3 m from the instrument- unless you want/must create problems.)