New Four Port Serial Interface Adds RS-232/422/485 Ports to PCI Express Bus

September 22, 2011

PCI Express 4-Port RS-232, RS-422, RS-485 Serial InterfacePRODUCT HIGHLIGHTS

  • Each port individually configurable for RS-232, RS-422, or RS-485
  • 16C954 buffered UARTs with 128-byte FIFOs
  • Each port supports data rates to 921.6K bps
  • Oscillator and clock prescaler support wide range of baud rates
  • Supports 9-bit protocol framing
  • RS-485 line termination, pull-up and pull-down resistors for each port are selectable via dipswitch
  • RS-485 ECHO can be enabled/disabled via dipswitch
  • PCI Express X1 compliant
  • Compatible with all standard size PCI Express slots
  • All modem control signals implemented in RS-232 mode
  • Automatic RS-485 enable/disable in hardware
  • Included 36″ cable terminates to four DB9M connectors (Item# CA143)

Introducing the new COMM+4.PCIe serial interface, which delivers the ultimate flexibility for expanding serial communications in a variety of test and measurement, process control and point-of-sale applications.

The COMM+4.PCIe serial interface provides four multifunction serial ports, each individually field-configurable for RS-232, RS-422, or RS-485. Each serial port utilizes a 16C954 UART with 128-byte Tx/Rx FIFOs that enables data rates to 921.6K bps for reliable high-speed communications in data intensive applications. This high-performance UART includes 9-bit framing support and is register compatible with legacy software applications designed for 16C550 UARTs. In addition, the board derives a 62.5 MHz clock from the PCI Express bus. This ultra high speed clock is divided by a flexible 8-bit clock prescaler with 1/8 steps to provide support for the widest range of standard and non-standard baud rates.

In RS-485 mode, the board provides automatic control of the RS-485 driver in hardware, allowing the 7404e to be used with standard serial communications without the risk of bus contention and data corruption. Additionally, RS-485 network termination, critical to robust multi-drop communication, can be selectively added to the circuit via DIP-switches. In RS-232 mode, all modem control signals are implemented for maximum compatibility with a variety of serial peripherals such as PLC’s, bar code readers, scales, and other data acquisition/control devices. Our SeaCOM software driver and utilities make installation and operation easy using Microsoft Windows and Linux operating systems.