Active Communication

Application:
PC controls RS485 bus system

Background information:
The UART is the central element of any serial interface card. The use of UARTs without integrated FIFO buffer at the high baud rates needed for example in modern modems for proper function will result in extreme loads on the CPU: each received or send character generates an interrupt. The buffer integrated into the UART allows sending and receipt of multiple characters before an interrupt follows. Since the processor is interrupted less often, it is more efficient. In practice this means that the port has a significantly higher data throughput. This is particularly critical in the case of fast modems and ISDN connections

Product properties:

• Equips PCs with RS422 and RS485 high-speed ports
• Manual configuration by means of DIL switch
• Flexible configuration
  • Standard base addresses COM1-COM4
  • Custom base addresses possible
  • Interrupts IRQ3-IRQ7, IRQ9-IRQ12
• UART 16550 with FIFO
• 1kV electrical isolation to the PC and between the ports
• Software compatible with standard RS232 cards
• No additional driver software required
• Conforms to standards both in office and industrial environments:
  • Increased noise immunity for industrial areas
  • Stricter noise emission for residential and commercial areas