How can I guarantee that different USB serial adapters will use the same COM port assignments?


When you connect a USB serial adapter to a computer, the operating system assigns individual COM port numbers to each serial port. Each USB serial adapter has a unique ID and the COM port numbers are retained even when the adapter is disconnected.

When you connect another USB serial adapter, it has a different ID. The new adapter is assigned the next available COM port number(s) by the operating system. However, this can be a problem if your application is expecting the new USB serial adapter to have the same COM port assignments as the previous USB serial adapter.

For this reason, Sealevel created versions of our USB serial adapters with a generic ID number. When one generic USB serial adapter is removed and another is connected, the computer will see the same generic ID and use the same COM port numbers with the new adapter.

This makes generic USB serial adapters perfect for applications that require the same COM port assignments regardless of which USB serial adapter is connected. Since generic USB serial adapters use the same ID, only one can be connected to a computer at a time. To add more serial ports, choose a generic USB serial adapter with more serial ports.

To order the generic versions of Sealevel serial adapters, ask for the “-GEN” modification or contact Sealevel Technical Support.

Note: Software configurable USB serial adapters are not available in generic versions due to their unique driver requirements.