I have just purchased a PCGU1000. During my initial installation of the item, i found the same problems as described by many others in this forum. I can not start it/turn it on! (after loading it says to check power and try again - but is detected by the initial start-up screen of the pclab2000se)
I tried many of the solutions offered by different persons on this form, but without any luck, and as a final test I purchased a exernal power supplied USB hub and connected it to this. And then I could turn it on
Now i have the following questions to Velleman that i hope you can help me and many others with:
Many of the other posts regarding the problem with turning the PCGU1000 on is several months old. Are there any breaking news in this matter from Velleman’s side?
It is described that the PCGU1000 must be listed in the device manager - in the universial serial bus controllers, but mine never turns up here - even when it is on. Is that a problem and if so, what can i do about it? Have allready tried to re-install several times. (My PCSU1000 does show up here!!!)
I must say that i find Velleman’s way of respondig in this forum to be very professional - nice. However this problem in particulary i find is lacking af full allround going thru by Velleman technical support! Many users have this specific problem, and from the many reply’s given by Velleman it seems obvious to me that Velleman, and many others, is still in the dark about this problem. So Velleman - please tells me and others what to do. How can i get rid of the external power supplied USB hub i currently need to make the PCGU1000 turn on?
Are they all soffering from a strange usb hardware problem or is it to do with drivers or??
Kind Regards and thanks for an othervise great product line and support!!
The optocouplers used in the PCGU1000 have a 5 to 15 mA recommended input current and a 20mA absolute maximum, and the original circuit fed that input from the +5V USB line via a 330Ω resistor providing 15.2 mA – IF the USB line is indeed 5.00V…
However, because PCs are not precision devices, the USB voltage is rarely exactly 5.00V, or particularly well regulated. I just this evening measured the open circuit voltage of four USB ports and got voltages ranging from 5.10V (a Dell GX620) to 5.65V on a wall-wart powered Belkin hub. At 5.65V the OEM circuit is pushing 17.1mA through the optocoupler.
Adding the LED will produce a 1.5V to 2.0V drop in the supply voltage, and thereby reduce the input current at a 5.00V USB line to 10mA, and 12.3mA at 5.55V–well within the optocoupler’s recommended range.
As somewhat of an aside, I have to once again express my delight in working with the Velleman support team! I wish other instrument manufacturers would understand that the people they sell these things to are not imbecilic dolts, and that they are capable of making well documented and engineered field modifications.
This, and full and complete documentation, used to be the norm for test equipment.
[quote]2) It is described that the PCGU1000 must be listed in the device manager - in the universial serial bus controllers, but mine never turns up here - even when it is on. Is that a problem and if so, what can i do about it? Have allready tried to re-install several times. (My PCSU1000 does show up here!!!)[/quote]This is OK. With the new driver the PCGU1000 is only under the Ports (COM & LPT). velleman.eu/downloads/files/ … rivers.pdf
