Common interface types of scanning gun are as follows:

SCSI (standard interface for minicomputer) : the maximum number of connected devices in this interface is 8, and the maximum transmission speed is usually 40M/S, which is faster and generally connected to high-speed devices.SCSI equipment installation is more complex, in PC generally to add SCSI card, easy to produce hardware conflict, but powerful.

EPP (enhanced parallel interface) : an enhanced bidirectional parallel transport interface with a maximum transmission speed of 1.5 MBPS.The advantages are no need to use other CARDS in the PC, unlimited number of connections (as long as you have enough ports), easy installation and use of the device.The disadvantage is that the speed is slower than SCSI.This interface replaces the SCSI interface in low - to mid-range situations where performance requirements are not high due to its ease of installation and use.

USB (universal serial bus interface) : up to 127 peripherals can be connected, the current USB1.1 standard maximum transmission speed is 12Mbps(1.5mb /s), and there is a secondary channel for the transmission of low speed data (1.5mbps (192KB/s)).The USB2.0 standard scan gun has a speed of 480Mbps(60MB/s).USB 3.0 runs at 5Gbps(640MB/s).With hot plug function, plug and play.With the establishment and promotion of USB standard driven by Intel, the scanning gun of this interface is gradually popularized.