Be sure the dongle is installed on the parallel port of a Windows operating system. Reinstall the appropriate Dallas dongle drivers for your version of Windows platform. The device drivers are available to our ISV's from our web site via a FLEXid installer, which ISV's can redistribute to their end users. The dongle I have sent to our customer with our licensed software does not work if any other dongle is attached to the computer system. Our dongle works if it is the only dongle connected to the system.
Most computer systems have only one parallel port.
However, by connecting one dongle on top of the other, you can attach multiple GSI dongles to the single parallel port. FLEXlm is capable of detecting all the attached dongles. Issue a new license to the customer based on the dongle they are currently using with the other FLEXlm based software. This way customer will have one dongle to authenticate two or more software. You would issue keys based on the customized hostid you created.