and first of all sorry for my english. But i have a problem with my K8090-Card and need help.
I am using the card for an automated brewing station. The card is a part of a larger project and is especially responsible for the on/off signals for the heating devices, water shutters, pumps and so on.
I have a program, written in delphi, wich sends the commands via the dll to the K8090. Evrything works fine, and all the command-signals from the software were correctly displayed in a log-window. But after some times (5 min to 2,5 h) the connection to the card get´s lost. No commands were accepted from the K8090. And it is not possible any more to read out the status of the card. The commands in the log-window of my software are still o.k., but they have no influence on the K8090.
Exactly the same problem exists even with the K8090 Demo Application 1.0. After a certain time, the connection is lost and no communication to the card is possible. Following activities have not brought an poitive result:
*unplug and replug the USB-cable.
*close and reopen the Demo-Application.
*using an second K8090.
*using an second computer
*update the drivers
*update the dll
The only way to bring back the card to work ist to unload and reaload the K8090-driver in the device-manager.
I know it´s quite tricky, but do you have any idea what might be the problem?
I think i have a possible explanation for the lost connection to the card.
In an ohter thread a read that:
This is also important: don’t unplug the device if the port is still connected to by software. This will definitely cause the port number to change. Always connect, disconnect, unplug.
So if the physical connection is lost once the com port changes and for this a reload of the driver is the only way to solve the problems. That fits quite good to my experiences.
For this, the next question is:
What is responsible for the the physical disconnetions?
My first thougt was the cable. But using an other cable doesn´t fix the problems. Even using an shorter cable (1m) does not have a positive effect.
Never unplug the K8090 while the COM port is in use. I doubt this has anything to do with your problem since you do not unplug the K8090 and a bad contact is unlikely.
You could verify if your USB port has power saving features enabled.
Please don´t think that i manually unplug the cable from the usb-slot. After some time the connection is lost and can not be refreshed until the driver is unloaded. And all this happens, while the cable is connected.
As you told me, i disabled all the power saving functions for the usb-ports. No effect. Time to disconnection 30 Minutes. Next time 10 Minutes.
Then i used better usb-cables (shielded). Again no positive effect.
An other interesting thing is, that at the same usb-cable is also connected a 1-wire-port. While the connection to the K8090 get´s lost, there is no problem with the connection to the 1-wire-port. All sensors which are connected to this port are serving perfect data. Only the connection to the K8090-card get´s lost. A tried even another K8090-card in this configuration. Exactly the same problems.
No, i haven´t tried an powerd usb-hub. Instead of this, i used different usb-cables for the K8090 and the 1-wire-port. So that the K8090 was directly conneted to my laptop.
(if anyone want´s to know. Yes my laptop is connected to the power supply system). Same problems.
And to the other question. There are no differences betwenn using a laptop or a desktop system. After a variing time, the usb-connection to the K8090 get´s lost and the com-port can not be contact in any way.
Is it possible, that there is a fluctuation in the power net, that makes a problem to the 500 mA-Trafo, which supplys the K8090-card, so that the connection gets lost?
An other observation is, that the usb-connection-led is lighting permanently, even when the connection gets lost.
Next idea.
Can the 3,5 kW heat up the K8090-card, so that it goes into a “saftey-mode” or whatever?
O.k., first of all, i fixed the problem.
Please don´t ask me why, but using an active (own power supply) instead an passive (supplied by the usb) usb hub solved the problem.
To make it clear. It was the same usb-hub, who could be used atice or passive. Only the active mode prevents the disconnections. Even a direct connetion between board an own usb-slot doesn´t work.
Might be, that the K8090 is not isolated, like the 1-wire hub is, which is galvanic isolated. Who knows,
Just a guess because I don’t know how many things you had plugged into the passive hub.
Maybe the current was dropping a little more then the K8090 liked because of the other devices.
The active hub should make sure that each port receives 500mA.