Advantech PCL-740 User manual

PCL-740
Serial Communication
RS-232/422/485/Current-Loop
Interface Card

Part No. 200074010 2nd Edition
Printed in Taiwan May 2001
Copyright Notice
This documentation and the software included with this product are
copyrighted 2001 by Advantech Co., Ltd. All rights are reserved.
Advantech Co., Ltd. reserves the right to make improvements to the
products described in this manual at any time without notice.
No part of this manual or software may be reproduced, copied,
translated or transmitted, in any form or by any means without the
prior written permission of Advantech Co., Ltd. Information provid-
ed in this manual is intended to be accurate and reliable. However,
Advantech Co., Ltd. assumes no responsibility for its use, nor for any
infringements of rights of third parties which may result from its use.
Acknowledgments
PC-LabCard is a trademark of Advantech Co., Ltd. IBM, PC and
PC/XT/AT are trademarks of International Business Machines
Corporation. MS-DOS, MASM, QuickBASIC, Microsoft C and MS-
PASCAL are trademarks of Microsoft Corporation. Intel is a trade-
mark of Intel Corporation. Turbo C and Turbo PASCAL are trade-
marks of Borland International.

Contents
Chapter 1 Introduction .................................................. 1
Description............................................................................. 2
Features ..........................................................................................3
Applications ...................................................................................3
Specifications.................................................................................4
Chapter 2 Hardware Installation ................................... 7
Initial Inspection ................................................................... 8
PCL-740 Jumper and Switch Locations............................. 9
Card Configuration ............................................................ 10
Jumper settings ................................................................... 12
Card installation ................................................................. 16
Appendix A Register structure and format ............... 17
Register Structure............................................................... 18
Programming example ....................................................... 21
Appendix B PC I/O Address Reference ........................ 25
PC I/O Address Usage......................................................... 26

Chapter 1 Introduction 1
1
Introduction
CHAPTER

2PCL-740 User's Manual
Description
The PCL-740 card enables RS-232, RS-422, RS-485 or current-loop
serial communication for applications in difficult environments. You
can configure its port to RS-232, RS-422, RS-485 or current-loop
using on-board jumpers.
The card features a 16C550 UARTs (with on-chip 16-byte FIFO)
making serial I/O more reliable. By buffering data into 16-byte
packets before putting it on the bus the UART drastically reduces the
CPU load. This makes the PCL-740 especially suitable for high
speed serial I/O applications and applications under MS Windows.
In RS-485 mode, the PCL-740 automatically senses the direction of
incomming data and switches its transmission direction accordingly.
Therefore no handshaking signal (e.g. RTS signal) is necessary. This
feature lets you simply and quickly build an RS-485 network with
just two wires. More importantly, application software previously
written for half duplex RS-232 environments, can be used without
modification.

Chapter 1 Introduction 3
Features
•Serial Port can be configured to RS-232/422/485 or current-loop
•16C550 FIFO UART (with 16-byte FIFO)
•Baud rate up to 115 Kbps
•IRQ selection: 3, 4, 5, 6, 7, 9, 10, 11, 12 or 15
•Complete RS-232 modem-control signals
•Space reserved for optional surge protection (RS-422/485 only)
•Space reserved for termination resistor (RS-422/485 only)
•LED indicator on each port indicates data flow
•Automatic data-flow control in RS-485 mode
Applications
•PLC monitoring and control
•Serial communication in harsh environments
•Data entry terminals
•Remote data acquisition and control
•Instrument controller, distributed control systems
•Interface to modem, bar code reader, scale, plotter
•Multidrop communication networks

4PCL-740 User's Manual
Specifications
Board
•Number of ports: 1
•Protocol selection: RS-232/422/485 or current-loop
•UART: 16C550 (16-byte FIFO)
•I/O address selection: From 200H to 3F8H
•IRQ selection: 3, 4, 5, 6, 7, 9, 10, 11, 12 or 15
•Power consumption: +5 V, 250 mA typical, 350 mA Max.
•Connectors: DB-9 male, DB-25 male
•Operating temperature: 32 to 122oF (0 to 50oC)
•Dimensions: 7.25" x 4.13" (18.4-cm x 10.5-cm)
•Weight: 0.2 Kg
RS-232 interface
•Signal driver/receiver: SN 75188, SN 75189
•Signals: TxD, RxD, RTS, CTS, DTR, DSR, DCD, RI, GND
•Mode: Asynchronous, full duplex
•Baud-rate: 50 to 115200 bps
•Stop bits: 1, 1.5, 2
•Parity: Even, odd or none
•Data bits: 5, 6, 7, 8

Chapter 1 Introduction 5
Current-loop interface
•Signal driver/Receiver: 6N136
•Signals: TxD+, TxD-, RxD+, RxD-
•Current value: 20 mA (Standard)
•Mode: Asynchronous, full duplex
•Baud-rate: 50 to 115200 bps
•Transmission distance: 1000 m
RS-422 Interface
•Signal driver/receiver: SN75176, SN75173
•Signals:
TxD+, TxD-, RxD+, RxD-, RTS+, RTS-, CTS+, CTS-, GND
•Mode: Asynchronous full duplex, point-to-point
•Max data rate: 115 Kbps
•Max data distances: 4000 feet (1220 meters)
RS-485 Interface
•Signal driver/receiver: SN75176
•Signals: DATA+, DATA-, GND
•Mode: Half duplex, multi-drop
•Max data rate: 115 Kbps
•Max data distances: 4000 feet (1220 meters)

6PCL-740 User's Manual

Chapter 2 Hardware Installation 7
2
Hardware
Installation
CHAPTER

8PCL-740 User's Manual
Initial Inspection
Depending on the option you ordered, you should find (in addition to
this manual) the following items inside the shipping container:
•PCL-740 1-port RS-232/422/485 or Current-loop Interface card
We carefully inspected the PCL-740 mechanically and electrically
before we shipped it. It should be free of marks and scratches and in
perfect working order on receipt.
As you unpack the PCL-740, check it for signs of shipping damage
(damaged box, scratches, dents, etc.). If it is damaged or it fails to
meet specifications, notify our service department or your local sales
representative immediately. Also notify the carrier. Retain the
shipping carton and packing material for inspection by the carrier.
After inspection we will make arrangements to repair or replace the
unit.
When you handle the PCL-740, remove it from its protective packag-
ing by grasping the rear metal panel. Keep the anti-vibration pack-
ing. Whenever you remove the card from the PC, store it in this
package for protection.
Warning Discharge your body’s stafic electric charge by
touching the back of the grounded chassis of the
system unit (metal) before handling the board.You
should avoid contact with materials that hold a static
charge such as plastic, vinyl and styrofoam. Handle
the board only by its edges to avoid static damage
to its integrated circuits. Avoid touching the exposed
circuit connectors.

Chapter 2 Hardware Installation 9
Protocol
Selection
Base
Address IRQ
Selection
Rx Active/Passive
Tx Active/Passive
Current-loop select
RS-422/485 RS-232/Current-loop
PCL-740 Jumper and Switch Locations

10 PCL-740 User's Manual
Card Configuration
Each port of the PCL-740 card has two associated status jumper
groups and one six position DIP switch. If you do not use the boards
default settings then these all require configuring prior to use. I/O
port base address, interrupt level, RS-232/422/485/current-loop
driver mode and receiver status all require setting up. The functions
of the relevant DIP switches and jumpers are shown below.
PCL-740 Switch and Jumper Options
Selection Switches/Jumpers Function
Protocol Selection JP5 RS-232/422/485/Current-Loop
Current-Loop Status JP2 Current-Loop TX active/passive
JP3,4 Current-Loop RX active/passive
Address Selection SW1 Base address for serial port
IRQ Selection JP1 Interrupt level for serial port
Please refer to the diagram on the previous page for jumper and DIP
switch locations.

Chapter 2 Hardware Installation 11
Default Settings
The board will be shipped in the RS-232 mode. If your requirements
are the same as this default setting, you may simply install the card
without the need for any setting up. The PCL-740 DIP switch and
jumper default settings are as shown below:
Protocol selection - RS-232 mode (JP5)
¡ ¡ ¡ ¡ JP5
¡ ¡ ¡ ¡
Interrupt level - IRQ4 (JP1)
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ JP1
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡
Base address - 3F8 (SW1)
SW1
ON
A3 A4 A5 A6 A7 A8
SW1
RS-232 RS-422 RS-485 C.L.
IRQ 15 12 11 10 9 7 6 5 4 3

12 PCL-740 User's Manual
Jumper settings
Protocol Selection
First you have to decide which mode each port will be operating in,
RS-232, RS-422, RS-485 or current-loop driver mode. Select the
correct jumper configuration on jumper JP5.
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡
Note: When either RS-232, RS-422 or RS-485 mode is selected, the
two current-loop Tx/Rx active/passive jumpers are inoperable.
Current-Loop jumpers (JP2,3,4)
Should you want to configure the PCL-740 to operate in the current-
loop mode, configure the main jumper for current-loop. You also
have to set Tx and Rx for active or passive mode. In the active mode
the Tx or Rx will generate the current required for data transfer over
the link. In the passive mode the current is generated by the card at
the other end of the link.
TxD RxD
¡ ¡ ¡ Active ¡ ¡ ¡ ¡
¡ ¡ ¡ ¡ ¡ ¡ ¡
¡ ¡ ¡ Passive
You may configure both the Tx and Rx to operate in the same mode,
or you can configure each Tx and Rx to operate in different modes.
Note: Whatever mode you select you must ensure that this is not the
same mode as the device that your PCL-740 is connected to. The
diagram on the next page shows a typical configuration.
RS-232 RS-422 RS-485 C.L.
RS-232 RS-422 RS-485 C.L.
RS-232 RS-422 RS-485 C.L. RS-232 RS-422 RS-485 C.L.
RS-232 RS-422 RS-485 Current-Loop
RS-232 RS-422 RS-485 C.L.

Chapter 2 Hardware Installation 13
I/O Address and Interrupt Setup
I/O Address Setup
The I/O base address the PC-740 is selectable by a 6 position DIP
switch, SW1. Refer to page 9 for the locations of the DIP switch
SW1. The base address can be set anywhere in the I/O address area
from hex 200 to hex 3F8. If you have more than one card installed
you must select a different base address for each card. The factory
default settings for the base address is Hex 3F8.
Desktop computer
Tx
Rx
Tx
Rx
Rx
Tx
Rx
Tx
Workstation
Plotter
Active
Passive
Passive
Active
Active
Active
Passive
Passive
PCL-740
port 1
port 1
or
SW1: Default base address - 3F8
The required switch settings for various base addresses are as shown
on the next page:
ON
A3 A4 A5 A6 A7 A8

Port base address (SW1)
Base address A3 A4 A5 A6 A7 A8
200-207 llllll
208-20F ¡lllll
- -
2E8-2EF ¡l ¡¡¡l
- -
2F8-2EF ¡¡¡¡¡l
- -
3E8-3EF ¡l ¡¡¡¡
- -
*3F8-3FF ¡¡¡¡¡¡
l:ON ¡:OFF *:Default
The following example shows how to set the base address to 2F8:
The switch sum is set to 2F8 = 200 + 80 + 40 + 20 + 10 + 8, (HEX).
NOTE: On the PCL-740 the address line A9 is does not appear on
the DIP switch as it is permanently hard-wired to HEX 200 on the
card.
ON
A3 A4 A5 A6 A7 A8
Base address Deci-
mal HEX
line value value
A3 8 8
A4 16 10
A5 32 20
A6 64 40
A7 128 80
A8 256 100
A9 512 200

IRQ 15 12 11 10 9 7 6 5 4 3
Interrupt Level (IRQ) Setting
The PCL-740 card is designed to access interrupt levels 3 up to level
15 with the exception of 8, 13, and 14. If the card is to be designated
as COM1:, the interrupt level must be set to IRQ4 (the default). For
COM2: the setting is IRQ3. Ensure that this does not conflict with
any other card's IRQ. Simply place the jumper link on the required
interrupt level as shown below:
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ JP1
¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡

16 PCL-740 User's Manual
Card installation
Warning! Turn off your PC’s power supply whenever you
install or remove the PCL-740 or its cables. Static
electricity can easily damage computer equipment.
Ground yourself by touching the chassis of the
computer (metal) before you touch any boards.
1. Turn off the computer. Turn the power off to any peripheral
devices (such as printers and monitors).
2. Disconnect the power cord and any other cables from the back of
the computer. Turn the PC if necessary to gain access to the
cables.
3. Remove the PC’s cover (refer to your user’s guide if necessary).
4. Locate the expansion slots or passive backplane (at the rear of the
PC) and choose any unused slot.
5. Remove the screw that secures the expansion slot cover to the PC
(save the screw to secure the interface card retaining bracket).
Remove the anti-vibration card clamp if supplied.
6. Carefully grasp the upper edge of the PCL-740 card. Align the
hole in the retaining bracket with the hole on top of the expansion
slot. Align the gold striped edge connector with the expansion
slot socket. Press the board firmly into the socket.
7. Replace the screw in the expansion slot retaining bracket.
Replace anti-vibration card holder.
8. Attach the DB-9 cable to the connector on the bracket.
9. Replace the PC’s cover. Connect the cables you removed in step
2. Turn the computer power on.
The board is now installed in the computer.

Appendix A Register structure and format 17
A
Register structure
and format
APPENDIX