What is Interface Card?
Any card that you plug into the motherboard of a computer to support connectivity between the main system bus and the external serial or parallel bus. Computers usually come with installed serial/parallel interface cards for connecting modems, printers, and other devices to your system, but in certain situations you might want to purchase a separate interface card.
These situations include:
- When you have an older computer whose serial interface card cannot support the newer fast 56-Kbps V.90 modems or whose parallel interface card cannot support IEEE 1284 bidirectional print devices such as the newer Hewlett Packard LaserJet print devices
- When you need a different serial interface such as RS-422/485 to connect your machine to special networking or industrial measurement equipment
Many different kinds of interface cards are available, including the following:
- RS-232 high-speed serial input/output (I/O) cards with 16550 universal asynchronous receiver-transmitter (UART) chips for connecting to high-speed modems and Integrated Services Digital Network (ISDN) terminal adapters. These cards can be either Industry Standard Architecture (ISA) or Peripheral Component Interconnect (PCI) bus cards and can support transfer speeds of up to 460.8 Kbps - much higher than the 115.2-Kbps rate supported by standard RS-232 interfaces.
- Enhanced Capabilities Port (ECP)/Enhanced Parallel Port (EPP) high-speed parallel I/O cards that support up to 2.5-Mbps transfer speeds.
- RS-422/485 interface cards for connecting to industrial sensor and measuring equipment. These cards can support up to 31 separate devices that can be located up to 4000 feet from the computer. Data transfer speeds are up to 460.8 Kbps.