There are four common interface types of barcode scanner:
SCSI (small computer standard interface)
The maximum number of connected devices in this interface is 8. Usually, the maximum transmission speed is 40M/S, which is faster and generally connected to high-speed devices. SCSI equipment installation is more complex, in the PC generally to add SCSI card, easy to produce hardware conflict, but powerful function.
EPP (enhanced parallel interface)
An enhanced bi-directional parallel transmission interface with a maximum transmission speed of 1. 5 MBPS. The advantages are no need to use other CARDS on the PC, unlimited number of connections (as long as you have enough ports), and easy installation and use of the device. The disadvantage is that the speed is slower than SCSI. This interface is easy to install and use, so it can replace SCSI interface in low - and medium-end applications.
USB (universal serial bus interface)
Up to 127 peripherals can be connected. The current USB1.1 standard has a maximum transmission speed of 12Mbps, and a secondary channel is used to transmit low-speed data. In the future if there is a USB2.0 standard bar code scanner speed may be extended to 480M/s. Hot plug and pull function, plug and play. The bar code scanner of this interface is gradually popularized with the establishment and promotion of USB standard pushed by Intel.
PS2 (keyboard interface)
Similar to USB usage, need a smart head conversion, the general purchase of scanning gun will be accompanied by. There are still a lot of companies using the PS2 interface.