TWAIN,SCSI and I/O Address

TWAIN
TWAIN defines a standard software protocol and API (Application Programming Interface) for the communication of application software with image acquisition devices (including scanners). TWAIN was developed to meet the need for consistency of application software with devices. TWAIN-compliant software and devices are those following the basic TWAIN requirements.

SCSI ID
SCSI is the abbreviation for Small Computer System Interface. The primary objective of the interface is to provide most computers with device independence within a class of devices. Thus, different devices can be chained  with or  added to the host computer without modifications of  system hardware and software. Each SCSI device occupies one address on the SCSI bus. The address (0 through 7) is used to select one of the devices to communicate with and is called the SCSI ID. The default  SCSI ID is 2 . You can change it  if there is a SCSI ID conflict in your environment.

I/O Address
The I/O address is what a scanner driver uses to communicate with an interface card. The MiraScan TWAIN driver performs an automatic configuration to find the I/O address. You can also adjust it manually.