OP-COM is a PC based diagnostic program.
It covers almost all Opel cars, even new cars with CAN-BUS based diagnostic, such as Vectra-C, Astra-H, Zafira-B.
The program lets you read out and clear trouble codes, shows you live data, lets you perform output test,  support remote, and do key programming.
The program supports many control units, like Engine, Automatic Transmission, ABS, Airbag, Engine Cooling module, Instrument Cluster, Electronic Climate Control, Body Control Unit, just to name a few examples.
The diagnostic inteface is USB port based, so there will be NO COMPATIBILITY ISSUES, with serial to USB converters.
The speed of the communication over the USB-BUS is enough to handle the awesome speed of the High-Speed CAN-BUS systems, which is currently 500kbps. This is the main reason, why only the USB port based interface is available for CAN-BUS.