ACCES I/O PRODUCTS INC 10623 Roselle Street, San Diego, CA 92121 TEL (858)550-9559 FAX (858)550-7322 MODEL PCI-ICM422(485)/2(4) USER MANUAL FILE: MPCI-ICM4S.
Notice The information in this document is provided for reference only. ACCES does not assume any liability arising out of the application or use of the information or products described herein. This document may contain or reference information and products protected by copyrights or patents and does not convey any license under the patent rights of 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.
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. Terms and Conditions If a unit is suspected of failure, contact ACCES' Customer Service department.
Table of Contents Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 RS422 Balanced Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RS485 Balanced Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . COM Port Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Communication Mode . .
List of Figures Figure 1-1: Figure 1-2: Figure 3-1: Figure 3-2: Figure A-1: PCI-ICM422/2/4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PCI-ICM485/2/4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simplified Termination Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Option Selection Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical RS485 Two-Wire Multidrop Network . . . . . . .
Chapter 1: Introduction These cards provide effective asynchronous serial communications in RS422 and RS485 networks on long communications lines in noisy environments. The cards feature independent serial ports and use type 16550 buffered UARTs. The data lines are opto-isolated from the computer and from each other to assure communication through large common mode noise. Both the RS422 and RS485 cards are 12.
PCI-ICM422/2(4) and 485/2(4) Manual A crystal oscillator is located on the card. This oscillator permits precise selection of baud rates up to 115,200 or, by changing a jumper, up to 460,800 with the standard crystal oscillator. The driver/receiver used, the SN75176B, is capable of driving extremely long communication lines at high baud rates. It can drive up to ±60 mA on balanced lines and receive inputs as low as a 200 mV differential signal superimposed on common mode noise of +12 V or -7 V.
The card is also available without this cable. If your card was purchased without the cable, there will be an "S1" appended to the model number. To ensure that there is minimum susceptibility to EMI and minimum radiation, it is important that the card mounting bracket be properly screwed into place and that there be a positive chassis ground. Also, proper EMI cabling techniques (cable connect to chassis ground at the aperture, shielded twisted-pair wiring, etc) should be used for the input/output wiring.
PCI-ICM422/2(4) and 485/2(4) Manual Figure 1-1: PCI-ICM422/2/4 Block Diagram (Only one serial channel shown) Figure 1-2: PCI-ICM485/2/4 Block Diagram Page 1-4 Manual MPCI-ICM4S.
Chapter 2: Installation The software provided with this card is contained on either one CD or multiple diskettes and must be installed onto your hard disk prior to use. To do this, perform the following steps as appropriate for your software format and operating system. Substitute the appropriate drive letter for your CD-ROM or disk drive where you see d: or a: respectively in the examples below. CD Installation DOS/WIN3.x 1. 2. 3. 4. Place the CD into your CD-ROM drive.
PCI-ICM422/2(4) and 485/2(4) Manual To copy the files on the master diskette to your hard disk, perform the following steps. a. Place the master diskette into a floppy drive. b. Change the active drive to the drive that has the diskette installed. For example, if the diskette is in drive A, type a:K. c. Type installK and follow the on-screen prompts. Directories Created on the Hard Disk The installation process will create several directories on your hard disk.
SAMPLES Samples for using ACCES32.DLL are provided in this directory. Using this DLL not only makes the hardware programming easier (MUCH easier), but also one source file can be used for both Windows 95/98 and WindowsNT. One executable can run under both operating systems and still have full access to the hardware registers. The DLL is used exactly like any other DLL, so it is compatible with any language capable of using 32-bit DLLs.
PCI-ICM422/2(4) and 485/2(4) Manual Findbase.exe DOS utility to determine an available base address for ISA bus , non-Plug-n-Play cards. Run this program once, before the hardware is installed in the computer, to determine an available address to give the card. Once the address has been determined, run the setup program provided with the hardware to see instructions on setting the address switch and various option selections. Poly.
Input/Output Connections A 37-pin D connector is on the mounting bracket and a three-foot-long breakout cable is included with the cards. That breakout cable terminates in separate 9-pin DBM connectors; one DB9 per port. If desired, the cards can be purchased without this breakout cable. In this latter case, an "S1" is added to the model number to signify absence of the breakout cable; viz PCI-ICM485/4S1. Manual MPCI-ICM4S.
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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 chapter. Operation 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. Installing a jumper at the locations labeled LDO and LDI apply 120S loads across the transmit (LDO)and receive (LDI) lines.
PCI-ICM422/2(4) and 485/2(4) Manual For example, if you have a four-port PCI-ICM card configured to use address 0xFC00, 0xFD00, 0xFD80, and 0xFE00 with an interrupt of 05, the values in the Registry are: Serial2 subkey: PortAddress = REG_DWORD 0xFC00 Interrupt = REG_WORD 5 DosDevices = REG_SZ COM3 InterruptStatus = REG_DWORD 0xFC08 PortIndex = REG_DWORD 1 Indexed =0 Serial4 subkey: PortAddress = REG_DWORD 0xFD80 Interrupt = REG_DWORD 5 DosDevices = REG_SZ COM5 InterruptStatus = REG_DWORD 0xFC08 PortIndex -
Figure 3-2: Option Selection Map Manual MPCI-ICM4S.
PCI-ICM422/2(4) and 485/2(4) Manual Page 3-4 Manual MPCI-ICM4S.
Chapter 4: Address Selection The PCI-ICM422/4 and PCI-ICM485/4 use four separate address spaces. COM A occupies 16 consecutive address locations and COM B, COM C, and COM D each occupy eight consecutive register locations. The two-port versions of these cards do not have ports COM C and COM D. 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.
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Chapter 5: Programming 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. 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.
PCI-ICM422/2(4) and 485/2(4) Manual When the BAUD jumper is in the X1 position, the UART clock frequency is 1.8432 Mhz. When the jumper is in the X4 position, the clock frequency is 7.3728 MHz. The following table lists popular divisor frequencies. Note that there are two columns to consider depending on the position of the BAUD jumper.
The second initializing step is to set the Line Control Register at Base Address +3. This register defines word length, stop bits, parity, and the DLAB. Bits 0 and 1 control word length and allow word lengths from 5 to 8 bits. Bit settings are extracted by subtracting 5 from the desired word length. 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.
PCI-ICM422/2(4) and 485/2(4) Manual The handler would first read the Interrupt Identification Register at Base Address +2. If the interrupt is for Received Data Available, the handler then reads the data. If no interrupt is pending, control exits the routine.
Chapter 6: Connector Pin Assignments A breakout cable is delivered with each card. The cable mates with a 37-pin connector on the card mounting bracket and, at the other ends of the cable, the popular 9-pin D sub-miniature male connector is used to interface with your communication lines. Those connectors are equipped with 4-40 threaded standoffs (female screw lock) to provide strain relief.
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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.
PCI-ICM422/2(4) and 485/2(4) Manual A balanced differential line receiver senses the voltage state of the transmission line across the two signal input lines. If the differential input voltage is greater than +200 mV, the receiver will provide a specific logic state on its output. If the differential voltage input is less than -200 mV, the receiver will provide the opposite logic state on its output.
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.
PCI-ICM422/2(4) and 485/2(4) Manual Page A-4 Manual MPCI-ICM4S.
Customer Comments If you experience any problems with this manual or just want to give us some feedback, please email us at: manuals@accesioproducts.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. (858)550-9559 FAX (858)550-7322 www.accesioproducts.
