There is no universal way to support all biometric devices. This a relatively new technology and all vendors are fighting for market space any one with their own API/SDK. New modalities of biometric are been developing and no have any retro compatibility with another biometric modalities. One of these is finger and palm vein. Another it is multispectral fingerprint capture that is a patented technology.
An initiative that tried to do that universal API was BioAPI, created by BioAPI Consortium. This standard becomes an ISO standard: ISO 19784-2. Therefore didn`t have participation of biggest vendors of biometric devices. And if you read the specification you will see how complicated is to use it...
Another initiative are been taken by NIST with webservices where any biometric device will have an internal webservice to supply biometric data and images and another system will be in charge of matching and decision process.
Anything different this is commercial tools like Griaule, Neurotechnology and Aware that tries to be a universal way to access biometric devices...