Universal PCI, RS-422 or RS-485 Serial Interface Cards (In a Low Profile form factor)
These are eight-port, asynchronous, serial communication cards designed for use on the PCI bus. They support RS-422 or RS-485 communications. These cards offer the best combination of high-density and high-speed communications in a low profile form factor. The cards meet the MD2 Low Profile PCI Bus Specification and can be used in applications where space is at a premium, such as thin-client servers and high-density rack-mount servers. The LPCI line has been designed for use in retail, hospitality, and point of sale systems as well as the gaming and defense industries.
The cards are 6.6 inches in length and 2.21 inches in height and may be installed in any available 3.3 or 5V PCI or PCI-X expansion slot. Normally, these units are supplied with an eight-connector breakout cable (no external breakout box required). However, they are available without that cable as models LPCI-COM422-8S1 and LPCI-COM485-8S1 for OEMs that fabricate their own cable harnesses.
Type 16C550 UARTS are used as the asynchronous communication elements. These include a 16-byte transmit/receive FIFO buffer to protect against lost data in multitasking systems while maintaining 100% compatibility with the original IBM serial port. ACCES also offers16850 UART functionality as an option to lower the CPU loading and allow for error-free data communications even at high simultaneous data rates.
Crystal oscillators located on the cards permit precise baud rate capability up to 115,200. Higher baud rates, up to 921,600 baud, are achieved by changing a jumper on the card. The driver/receivers used, type SN75176B, are capable of driving long communication lines at high baud rates. They can drive up to ±60 mA on balanced lines and receive inputs as low as 200 mV differential signal superimposed on common mode noise of +12 to -7V. In case of communication conflict, the driver/receivers feature thermal shutdown.
Since these are PCI-Bus cards, the operating system determines the resources assigned to the card. As a result, you cannot set or change the card’s base address. You can only determine what the system has assigned. The PCI Bus supports 64K of I/O bus address space so your card’s address may be located anywhere in the 0000 to FFFF range.
AUTO TRANSCEIVER CONTROL
In RS-485 communications, the driver must be enabled and disabled as needed, allowing all cards to share a two wire cable. The LPCI-COM485-8 card controls the driver automatically. With automatic control, the driver is enabled when data is ready to be transmitted. The driver remains enabled for one additional character’s transmission time after data transfer is complete and then is disabled. The receiver is also normally enabled, then disabled during RS-485 transmissions, and then re-enabled after transmission is completed (plus one character transmission time). The LPCI-COM485-8 automatically adjusts it’s timing to the baud rate of the data. (NOTE: Thanks to the automatic control feature, the card is ideal for use in WIN9x/NT/2K/XP applications)
A complete driver support package is provided including an easy to use Windows terminal program for testing out your COM ports. This helps simplify verification of proper operation. The card installs as standard Windows COM ports in all Windows operating systems including the ability to re-direct the starting COM port number at COM3 in Windows NT 4.0. The card is supported by most operating systems and includes a free DOS, Linux and XP -> 10, both 32 & 64 bit compatible software package. This includes sample programs and source code in “C” for DOS, and Visual Basic, Delphi, and Visual C++ for Windows. Also included is a graphical setup program in Windows.
Last updated on September 13th, 2021