Related Manuals for Acces I/O products PCI-COM485/4
Summary of Contents for Acces I/O products PCI-COM485/4
- Page 1 sales@artisantg.com artisantg.com (217) 352-9330 | Click HERE Find the Acces PCI-COM485-4 at our website:...
- Page 2 10623 Roselle Street, San Diego, CA 92121 • (858) 550-9559 • FAX (858) 550-7322 contactus@accesio.com • www.accesio.com MODEL PCI-COM485/4 USER MANUAL FILE: PCI-COM485-4.Gb...
- Page 3 ACCES, nor the rights of others. IBM PC, PC/XT, and PC/AT are registered trademarks of the International Business Machines Corporation. Printed in USA. Copyright 2000, 2005 by ACCES I/O Products Inc, 10623 Roselle Street, San Diego, CA 92121. All rights reserved.
- Page 4 Warranty Prior to shipment, ACCES equipment is thoroughly inspected and tested to applicable specifications. However, should equipment failure occur, ACCES assures its customers that prompt service and support will be available. All equipment originally manufactured by ACCES which is found to be defective will be repaired or replaced subject to the following considerations.
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Page 5: Table Of Contents
Table of Contents Chapter 1: Introduction............................5 Specifications..............................6 Figure 1-1: Block Diagram(Only one serial channel shown) ................7 Chapter 2: Installation............................8 Chapter 3: Option Selection ..........................10 Figure 3-1: Simplified Termination Schematic ..................... 10 Figure 3-2: Option Selection Map......................... 12 Chapter 4: Address Selection ........................... -
Page 6: Chapter 1: Introduction
Chapter 1: Introduction This Serial Interface Card was designed for effective multipoint transmission in RS485 (EIA485) protocol. The card is 6.0 inches long and may be installed in 5-volt PCI-bus slots of IBM PC or compatible computers. The card features four independent, asynchronous RS485 serial ports, type 16550 buffered UARTS, and, for Windows compatibility, automatic control to transparently enable/disable the transmission drivers. -
Page 7: Specifications
Auto-RTS Transceiver Control In RS485 communications, the driver must be enabled and disabled as needed, allowing all cards to share a two wire cable. The 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. - Page 8 Figure 1-1: Block Diagram(Only one serial channel shown)
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Page 9: Chapter 2: Installation
Chapter 2: Installation A printed Quick-Start Guide (QSG) is packed with the card for your convenience. If you’ve already performed the steps from the QSG, you may find this chapter to be redundant and may skip forward to begin developing your application. - Page 10 Hardware Installation Make sure to set switches and jumpers from either the Option Selection section of this manual or from the suggestions of SETUP.EXE. Do not install card into the computer until the software has been fully installed. Turn OFF computer power AND unplug AC power from the system. Remove the computer cover.
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Page 11: Chapter 3: Option Selection
Chapter 3: Option Selection To help you locate the jumpers described in this section, refer to the Option Selection Map at the end of this section. Operation of the serial communications section is determined by jumper installation as described in the following paragraphs. Terminations A transmission line should be terminated at the receiving end in its characteristic impedance. - Page 12 Interrupts Please note that, in WindowsNT, changes must be made to the system registry to support IRQ sharing. The following is excerpted from "Controlling Multiport Serial I/O Cards" provided by Microsoft in the MSDN library, documentid:mk:@ivt:nt40res/D15/S55FC.HTM, also available in the WindowsNT Resource Kit.
- Page 13 Figure 3-2: Option Selection Map...
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Page 14: Chapter 4: Address Selection
Chapter 4: Address Selection The card uses four separate address spaces. COM A occupies 16 consecutive register locations and COM B, COM C, and COM D each occupy eight consecutive register locations. PCI architecture is Plug-and-Play. This means that the BIOS or Operating System determines the resources assigned to PCI cards rather than you selecting those resources with switches or jumpers. -
Page 15: Chapter 5: Programming
Chapter 5: Programming Sample Programs There are sample programs provided with the card in C, Pascal, QuickBASIC, and several Windows languages. DOS samples are located in the DOS directory and Windows samples are located in the WIN32 directory. Windows Programming The card installs into Windows as COM ports. - Page 16 Initialization Initializing the chip requires knowledge of the UART's register set. The first step is to set the baud rate divisor. You do this by first setting the DLAB (Divisor Latch Access Bit) high. This bit is Bit 7 at Base Address +3.
- Page 17 Bit 2 determines the number of stop bits. There can be either one or two stop bits. If Bit 2 is set to 0, there will be one stop bit. If Bit 2 is set to 1, there will be two stop bits. Bits 3 through 6 control parity and break enable.
- Page 18 the data. The process of checking the bit until it goes high followed by a write is repeated until no data remains. The following C code fragment demonstrates this process: outportb(BASEADDR +4, inportb(BASEADDR +4)|0x02); /*Set RTS bit without altering states of other bits*/ while(data[i]);...
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Page 19: Chapter 6: Connector Pin Assignments
Chapter 6: Connector Pin Assignments The popular 9-pin D subminiature connector is used for interfacing to communication lines. The connector is equipped with 4-40 threaded standoffs (female screw lock) to provide strain relief. Pin No. RS485 Functions Tx+ and Rx+ Tx- and Rx- GND Ground Table 6-1: Connector Pin Assignments... -
Page 20: Appendix A: Application Considerations
Appendix A: Application Considerations Introduction Working with RS422 and RS485 devices is not much different from working with standard RS232 serial devices and these two standards overcome deficiencies in the RS232 standard. First, the cable length between two RS232 devices must be short; less than 50 feet at 9600 baud. Second, many RS232 errors are the result of noise induced on the cables. - Page 21 Balanced Differential Signals The reason that RS422 and RS485 devices can drive longer lines with more noise immunity than RS232 devices is that a balanced differential drive method is used. In a balanced differential system, the voltage produced by the driver appears across a pair of wires. A balanced line driver will produce a differential voltage from +2 to +6 volts across its output terminals.
- Page 22 RS485 Data Transmission The RS485 Standard allows a balanced transmission line to be shared in a party-line mode. As many as 32 driver/receiver pairs can share a two-wire party line network. Many characteristics of the drivers and receivers are the same as in the RS422 Standard. One difference is that the common mode voltage limit is extended and is +12V to -7V.
- Page 23 Customer Comments If you experience any problems with this manual or just want to give us some feedback, please email us at: manuals@accesio.com.. Please detail any errors you find and include your mailing address so that we can send you any manual updates. 10623 Roselle Street, San Diego CA 92121 Tel.
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