Hi,
I’ve been using many VM8090 modules over the past few years but have an intermittent issue with one pc at the moment. I also have identical pcs in use with these modules without the problem.
On a clean install (Windows 10 Pro), the demo program runs fine. After a reboot, the demo program fails to connect to the com port with error ‘Failed to Connect. Access is Denied’. I’ve found that repeatedly trying to connect in quick succession will eventually work. If I unplug / re-plug the module, it sometimes connects first time but not always. I’ve also tried several modules to make sure one isn’t faulty in some way.
Do you have any ideas what might cause this please? Thanks
I should also add that when it does eventually connect, when a relay is switched on, the ‘led on’ status does not work on the demo screen although relay is switched on / off as expected each time. Does this give a clue as to what is / is not happening?
I’ve currently got this issue with another pc (identical model as it happens), although I also have several more of the same pc working fine with the modules.
I’ve tried with a usb 2 hub, a usb 3 hub (including with external power supply). I’ve also tried module plugged directly into pc port (usb 3) with the same issue.
One thing I have noticed is that sometimes when it does connect and relays are switched on, the demo program does not illuminate the on-screen red leds - what does this signify in the software as this may give me a clue as to what is wrong on the usb side of things?
What is the situation / recommendation regarding usb 2 / usb 3 ports while we’re at it please? Any compatibility issues?
I don’t think the K8090 will work with USB 3.
I found this in the features.
Features
USB-controlled relay card
manual operation for toggle, momentary or timer operation (selectable through software)
timer settings up to 18 hours (DLL function)
optional open collector connectivity (push button simulation
DLL for own software development (download only)
event-driven and open protocol
two way PC communication (USB Event return)
optional VDR (type VDR300) transient suppression for use with inductive loads
LED indication for power and relay action
minimum system requirements:
PC running USB compatible Windows version
[color=#BF0000]USB1.1 and USB2.0 full speed compatible[/color]
internet connection for software download
optional DIN rail enclosure: B8006 (Note: cut out the USB connector)
OK. I have had them working on USB3-only machines but I guess it’s not recommended.
Could you clarify what causes the on-screen leds to not work sometimes on the demo program? As I said, everything can work as expected except for this one small thing.