Question : Problem: Serial Com Ports Vs. USB Multi Serial Com Ports : Do they behave the same ??????

Recently I purchased a USB multi serial com port at :    http://www.titanelectronics.com/show/usb8com.htm
 :  from a USB port I added 8 serial com ports.

The point is that I run an aplicati0n, for Automatic Vehicle Location, aided by GPS device that has to be called in, by a

dialup procedure with a serial modem (normally a PCI modem).  In my dell server (a Dell PowerEdge 2600 dual Xeon, 1 GB DDR,

Windows 2003, with Citrix Metaframe XP FR3 server)  I have no PCI slots, just PCIX. So I needed to communicate with the GPS

devices via external modem .

When the external modem is attached to the built in serial com port in the back of the server the software works just fine,

but when I use the USB multi serial port hub the software doesn't work properly.

Reads the device's coordinates, but does not answer specific requests. So I'm asking my self, what can possibly alter the

communication procedure or protocol that makes the USB multi serial port obsolete on reading the communication that a normal

com port does ?     There's something about USB that makes the communication behave diferent way on a USB multi serial port

than a regular serial com port. ?  

I need that the USB multi serial com port behave exactly as a regular com port on the computer.  


Coments ??????????????????????????????????????????????

Thanks,

SenTnel

Answer : Problem: Serial Com Ports Vs. USB Multi Serial Com Ports : Do they behave the same ??????

Possibly the software needs to communicate in a specialized manner with the modem directly, to send/receive particular instructions and the drivers needed for USN to serial conversion can't handle this 100% correctly. I think you should talk to the software makers or the makers of the USB thingy and see if either of them can help you with better drivers or  any other suggestions.
/RID