Quatech RS-422 User manual

DSCLP-200/300
Two Channel RS-422/485 Asynchronous
Communications Adapter
for PCI bus
User's Manual
QUATECH, INC. TEL: [phone]
662 Wolf Ledges Parkway FAX: [phone]
Akron, Ohio 44311 http://www.quatech.com

?2002 Quatech, Inc.
NOTICE
The information contained in this document cannot be reproduced in any form
without the written consent of Quatech, Inc. Likewise, any software programs that
might accompany this document can be used only in accordance with any license
agreement(s) between the purchaser and Quatech, Inc. Quatech, Inc. reserves the right
to change this documentation or the product to which it refers at any time and without
notice. The authors have taken due care in the preparation of this document and every
attempt has been made to ensure its accuracy and completeness. In no event will
Quatech, Inc. be liable for damages of any kind, incidental or consequential, in regard to
or arising out of the performance or form of the materials presented in this document or
any software programs that might accompany this document.
Quatech, Inc. encourages feedback about this document. Please send any
written comments to the Technical Support department at the address listed on the
cover page of this document.
DOS, Windows 95, Windows NT are trademarks or registered trademarks of Microsoft Corporation.
OS/2 is a registered trademark of IBM Corporation. All other trademarks or registered trademarks
are property of their respective owners.
iv DSCLP-200/300 User's Manual

WARRANTY INFORMATION
Quatech, Inc. warrants the DSCLP-200/300 to be free of defects for
five(5)yearsfrom the date of purchase. Quatech, Inc. will repair or replace any
board that fails to perform under normal operating conditions and in accordance with
the procedures outlined in this document during the warranty period. Any damage that
results from improper installation, operation, or general misuse voids all warranty rights.
Please complete the following information and retain for your records. Have
this information available when requesting warranty service.
DATE OF PURCHASE:
MODEL NUMBER: DSCLP-200/300
PRODUCT DESCRIPTION: Two Channel RS-422/485 Asynchronous
PCI Bus Communications Adapter
SERIAL NUMBER:
DSCLP-200/300 User's Manual i

Declaration of Conformity
Manufacturer's Name: Quatech Inc.
Manufacturer's Address: 662 Wolf Ledges Parkway
Akron, Ohio 44311 (USA)
Application of Council Directive: 89/336/EEC
Standards to which
Conformity is Declared: * EN50081-1 (EN55022,
EN60555-2, EN60555-3)
* EN50082-1 (IEC 801-2,
IEC 801-3, & IEC 801-4)
Type of Equipment: Information Technology
Equipment
Equipment Class: Commercial, Residential, & Light
Industrial
Product Name: PCI DualSerial Communications
Card
Model Number : DSCLP-200/300 (750,IND)
ii DSCLP-200/300 User's Manual

Table of Contents
28
10 Troubleshooting .................................................27
9Specifications ....................................................26
8PCI Resource Map ..............................................257.7 RS-422/485 Peripheral Connection ................................247.6 Termination Resistors ............................................227.5 Half-Duplex/Full-Duplex Selection .................................217.4 AUXIN/AUXOUT Loopback ....................................217.3 XCLK .........................................................207.2 RCLK .........................................................207.1 RTS/CTS Handshake ............................................19
7External Connections ...........................................176.3.1 QTPCI.EXE .............................................166.3 DOS and other operating systems ..................................166.2 OS/2 ..........................................................166.1 Windows NT ...................................................16
6Other Operating Systems .......................................135.2 Viewing Resources with Device Manager ...........................125.1 Using the "New Hardware Found" Wizard ..........................12
5Windows 95 Configuration .....................................114.4.2 Clock Rate Multiplier ......................................104.4.1 Enhanced Serial Adapter Identification .......................104.4 Options Register ................................................. 94.3 Interrupt Status Register ...........................................94.2 Enabling the Special Registers ......................................84.1 Base Address and Interrupt Level (IRQ) .............................8
4Address Map and Special Registers ............................7
3Hardware Installation ...........................................6
2.4.2 Force High-Speed UART Clock (X2, X4, or X8,
J10-J12) ........................................................
52.4.1 Enable Scratchpad Register (SPAD, J13) .....................52.4 Clock Rate and Optional Registers ..................................42.3 Full-duplex/Half-duplex Operation ..................................42.2 Signal Connections ................................................32.1 RS-422 or RS-485 Signal Line Termination ..........................3
2Hardware Configuration ........................................21.1.2 "750" Option --- UART Upgrade ............................21.1.1 "IND" Option --- Surge Suppression Upgrade .................21.1 Optional Features .................................................1
1General Information .............................................
DSCLP-200/300 User's Manual iii

1General Information
The Quatech, Inc. DSCLP-200/300(two-port) and SSCLP-200/300
(one-port) provides upto provides two RS-422 or RS-485 asynchronous serial
communication interfaces for IBM-compatible personal computer systems using the
PCI expansion bus. The DSCLP-200/300 uses Quatech's new Enhanced Serial
Adapter design. Legacy serial port data rates are limited to a maximum of 115,200 bits
per second. Quatech Enhanced Serial Adapters can achieve data rates as high as
460,800 bits per second. This discussion relates to DSCLP-200/300.A
SSCLP-200/300 is just one port in the discussion.
As a PCI device, the DSCLP-200/300 requires no hardware configuration.
The card is automatically configured by the computer's BIOS or operating system. The
two serial ports share a single interrupt line and are addressed in a contiguous block of
16 bytes. Aspecial interrupt status register is provided to help software to manage the
shared interrupt.
The DSCLP-200/300's serial ports are implemented using 16550 Universal
Asynchronous Receiver/Transmitters (UARTs). These UARTs contain hardware
buffers (FIFOs) which reduce processing overhead and allow higher data rates to be
achieved. The 16550 contains a 16-byte FIFO and can transmit and receive data at a
rate of up to 230,400 bits per second.
The DSCLP-200/300 is supported under several popular operating systems
and environments. Contact the sales department for details on current software
offerings. Most device drivers are available for download from the Quatech world wide
web site at http://www.quatech.com.
DSCLP-200/300 User's Manual 1

2Hardware Configuration
The DSCLP-200/300 is automatically configured at boot time by the
computer's BIOS or operating system. There are no required switches or jumpers to
set for installation.
This chapter lists a number of jumper settings that control various hardware
features. Jumpers J1-J4,located in a column near the D-9 connectors, control the
RS-422 or RS-485 signal line termination. Jumpers J5-J8, located in a column just to
the right of J1-J4, control how signals are routed from the UARTs to the connector, as
well as full- or half- duplex operation. Jumpers J10-J13, grouped together at the end of
the board opposite the D-9connectors, control special options.
Any changes from the factory default should be made before installing the
DSCLP-200/300 in the computer.
2.1RS-422 or RS-485 Signal Line Termination
Jumpers J6-J9allow the selection of 100-ohm RS-422 termination, 120-ohm
RS-485 termination, or no termination at all. The factory default, shown in Figure 1, is
RS-422 termination. For full details, see page 24.
13
RS-422 termination
(100 ohms)
(factory default)
Jumpers J6-J9
4
2
Figure 1--- Factory default signal termination settings
2DSCLP/SSCLP-200/300 User's Manual

2.2Signal Connections
The DSCLP-200/300 provides each of two serial ports with four differential
signal pairs: TxD, RxD, AUXOUT, and AUXIN. TxD and RxD are always present at
the connector. The AUXOUT and AUXIN signals can be used to support RTS/CTS
handshaking, external clocking, or external signal loopback. The factory default
configuration, as shown in Figure 2, is a loopback of AUXOUT to AUXIN at the
connector, with RTS and CTS looped back on the board. There is an extensive
discussion of this topic starting on page 19.
2.3Full-duplex/Half-duplex Operation
The DTR or RTS modem control output of the UART can be used to enable
and disable the transmit drivers. The inverse of these signals can also be used to enable
and disable the receivers. These options are selectable per channel. The factory
default, as shown in Figure 2, is for both the drivers and receivers of both channels to
be continuously enabled. Two spare jumpers are installed in neutral positions. For
details, refer to page 22.
The DSCLP-200/300 is shipped from the factory with each channel configured
with No jumpers on J10-23. The following conditions occur: CTS=AUXIN,
AUXOUT=RTS, RCLK=TCLK, TXEN=1 AND RXEN=1.
Jumpers J10-J23 define the options for this card:
DSCLP-200/300 User's Manual 3

SPAD
X4
X2
J2
J4
J5
CTS0_SEL
AUX0_SEL0
AUX0_SEL1
J10
J11
J12
RCLK0_SEL
TGL0_SEL0
TGL0_SEL1
J13
J14
J15
RXEN0_SEL
CTS1_SEL
AUX1_SEL0
J16
J17
J18
AUX1_SEL1
RCLK1_SEL
TGL1_SEL0
J19
J20
J21
TGL1_SEL1
RXEN1_SEL
J22
J23
Right Card Edge Jumpers
2.3.1CTS0_SEL, CTS1_SEL (J10,17)
With NO jumpers on J10 or J17 the mode selection is CTS=AUXIN. With
Jumpers installed the mode selection is CTS=RTS.
2.3.2AUX0_SEL1,0, AUX1_SEL1,0 (J12,11,19,18)
With NO jumpers on J12 or J19 the mode selection is AUXOUT=RTS. With
Jumpers installed on J12 or J19 and NO jumpers installed on J11 or J18, the mode
selection is AUXOUT=TCLK. With Jumpers installed on J12, J11 or J19, J18, the
mode selection is AUXOUT=AUXIN.
2.3.3RCLK0_SEL, RCLK1_SEL (J13, 20)
4DSCLP/SSCLP-200/300 User's Manual

With NO jumpers on J13 or J20 the mode selection is RCLK=TCLK. With
Jumpers installed on J13 or J20 the mode selection is RCLK=AUXIN.
2.3.4TGL0_SEL1,0, TGL1_SEL1,0 (J15,14,22,21)
With NO jumpers on J15,14, or J22,21 the mode selection is TXEN=1. With
Jumpers installed on J14 or J21 and NO jumpers on J15 or J22, the mode selection is
TXEN=DTR. With Jumpers installed on J15 or J22 and NO jumpers on J14 or J21,
the mode selection is TXEN=RTS.With Jumpers installed on J15, J14 or J22, J21, the
mode selection is TXEN=”Auto Toggle”.
2.3.5RXEN0_SEL, RXEN1_SEL (J16, 23)
With NO jumpers on J16 or J23 the mode selection is RXEN=1. With
Jumpers installed on J16 or J23 the mode selection is RCLK=!TXEN.
2.4Clock Rate and Optional Registers
Figure 3 shows the jumper configuration as shipped from the factory, with two
spare jumpers applied in neutral positions. Remove one or both and apply as shown in
following subsections to set optional features.
SPAD
X4
X2
J2
J4
J5
Figure 3--- Factory default clock rate and options settings
2.4.1Enable Scratchpad Register (SPAD, J2)
In the default configuration, an Interrupt Status Register and an Options Register
(see page 10) replace the scratchpad (base address + 7) of each UART. If the SPAD
jumper is applied as in Figure 4, the UART scratchpad registers are enabled, and the
Interrupt Status Register and the Options Register are not available.
DSCLP-200/300 User's Manual 5

SPAD
X4
X2
J2
J4
J5
Figure 4--- Enable scratchpad registers
2.4.2Force High-Speed UART Clock (X2 or X4, J4-J5)
These jumpers force an increase of the UART input clock frequency by a factor
of two, four, or eight. This feature can allow legacy software to use baud rates above
115,200 bits per second. It is also useful if the serial port device driver does not
directly support setting the higher baud rates through the Options Register (see page
10). If one of these jumpers is applied, it overrides any value written to the Options
Register to set the clock multiplier by software. The effective baud rate will be either
two or four times the value for which the UART itself is programmed.
The factory default is none of these jumpers applied, which allows for software
control of the clock multiplier via the Options Register. The Options Register powerup
default is for a standard times-1 clock of 1.8432 MHz for compatibility with standard
serial ports.
Figure 5--- Clock multiplier jumper options
SPAD
X4
X2
J2
J4
J5
factory default
6DSCLP/SSCLP-200/300 User's Manual

SPAD
X4
X2
J2
J4
J5
X4 mode
SPAD
X4
X2
J2
J4
J5
X2 mode
DSCLP-200/300 User's Manual 7

3Hardware Installation
1. Turn off the power of the computer system in which the DSCLP-200/300 is to
be installed.
2. Remove the system cover according to the instructions provided by the
computer manufacturer.
3. Make any desired optional jumper setting changes.
4. Install the DSCLP-200/300 in any empty PCI expansion slot. The board
should be secured by installing the Option Retaining Bracket (ORB) screw.
5. Replace the system cover according to the instructions provided by the
computer manufacturer.
6. Attach and secure the cable connectors to the desired equipment.
7. Turn on the power of the computer system.
The output of the DSCLP-200/300 is two female 9-pin D-connectors.
J2
J4
J5
SPAD
X4
X2
Clock multiplier/
scratchpad select
Termination select
Interface configuration
J1
J2
J3
J4
J5
J6
J7
J8
port 1
port 2
Serial
Port
2
Serial
Port
1
Figure 6--- Jumper/connector locations
8DSCLP/SSCLP-200/300 User's Manual

4Address Map and Special Registers
This chapter explains how the two UARTs and special registers are addressed,
as well as the layout of those registers. This material will be of interest to programmers
writing driver software for the DSCLP-200/300.
4.1Base Address and Interrupt Level (IRQ)
The base address and IRQ used by the DSCLP-200/300 are determined by
the BIOS or operating system. Each serial port uses 8 consecutive I/O locations. The
two ports reside in a single block of I/O space in eight byte increments, for a total of 16
contiguous bytes, as shown in Figure 7.
Base Address + 8 to Base Address + 15Port 2
Base Address + 0 to Base Address + 7Port 1
I/O Address RangeChannel
Figure 7--- Port Address Map
All two serial ports share the same IRQ. The DSCLP-200/300 signals a
hardware interrupt when any port requires service. The interrupt signal is maintained
until no port requires service. Interrupts are level-sensitive on the PCI bus.
The base address and IRQ are automatically detected by the device drivers
Quatech supplies for various operating systems. For cases where no device driver is
available, such as for operation under DOS, Quatech supplies the "QTPCI" DOS
software utility for manually determining the resources used. See page 17 for details.
DSCLP-200/300 User's Manual 9

4.2Enabling the Special Registers
The DSCLP-200/300 contains two unique registers, an Interrupt Status
Register and an Options Register. These registers are enabled when the SPAD jumper
(J13) is removed (factory default). They replace the UART Scratchpad Register on
accesses to register address 7.
The Interrupt Status Register and Options Register are accessed through the
scratchpad location of any UART. The DLAB bit of the UART (Line Control Register,
bit 7) is used to select between the two registers. The most recent write of a DLAB bit
in any UART selects between the two registers as shown in Figure 8.
Scratchpad RegistersappliedXOptions Registerremoved1Interrupt Status Registerremoved0
Register selected for
address 7 accesses
SPAD JumperDLAB Bit
Figure 8--- DLAB bit selects between special registers
4.3Interrupt Status Register
The read-only Interrupt Status Register can be used to quickly identify which
serial ports require servicing after an interrupt. Reading the Interrupt Status Register will
return the interrupt status of the entire DSCLP-200/300, as shown in Figure 9. The
individual bits are cleared as the interrupting ports are serviced. The interrupt service
routine should ensure that the interrupt status register reads zero before exiting.
Port 1 --- 1 if interrupt pending0
Port 2 --- 1 if interrupt pending1
0 (not used)2
0 (not used)3
0 (not used)4
0 (not used)5
0 (not used)6
0 (not used)7 (MSB)
DescriptionBit
Figure 9--- Interrupt Status Register
10 DSCLP/SSCLP-200/300 User's Manual

4.4Quatech Modem Control Register
The Quatech Modem Control Register can be used to setup each port. To
access QMCR write a 0xBF to the LCR(base + 3) and a 0x10 to the Opt
Reg(base+7).This will allow the user read/write access to QMCR.The QMCR of the
entire DSCLP-200/300, as shown in Figure 9a. The individual bits are cleared as the
interrupting ports are serviced. The QMCR will need to be written to after the setup by
writing a 0x00 to (base+B).
00 - TXEN “Auto”
01 - TXEN=DTR
10 - TXEN=RTS
11 - TXEN TOGGLES DURING X-MIT
1-0
0 - AUXOUT=RTS
1- AUXOUT=TCLK
2
0 - RCLK=TCLK,CTS=AUXIN
1 - RCLK=AUXIN, CTS=RTS
3
0 - Bits 2 and 3 are used
1 - RCLK=TCLK,CTS=RTS,
AUXOUT=AUXIN
4
0 - RXEN=1
1 - RXEN=!TXEN
5
0 (always 0)6
0 (always 0)7 (MSB)
DescriptionBit
Figure 9a --- Quatech Modem Control Register
DSCLP-200/300 User's Manual 11

4.5Options Register
The Options Register allows software to identify the DSCLP-200/300 as a
Quatech Enhanced Serial Adapter. It also allows software to set the UART clock rate
multiplier. Figure 10 shows the structure of the Options Register.
The powerup default of the Options Register is all bits zero.
Clock rate multiplier bit 0RR00
Clock rate multiplier bit 1RR11
(reserved, 0)-2
(reserved, 0)-3
(reserved, 0)-4
(reserved, 0)-5
ID bit 0ID06
ID bit 1ID17 (MSB)
DescriptionNameBit
Figure 10--- Options Register bit definitions
4.5.1Enhanced Serial Adapter Identification
The ID bits are used to identify the DSCLP-200/300 as a Quatech Enhanced
Serial Adapter. Logic operations are performed such that the values read back from
these bits will not necessarily be the values that were written to them. Bit ID1 will return
the logical-AND of the values written to ID[1:0], while bit ID0 will return their
exclusive-OR.
Software can thus identify a Quatech Enhanced Serial Adapter by writing the
ID bits with the patterns shown in the "write" column of Figure 11, then reading the bits
and comparing the result with the patterns in the "read" column. Matching read patterns
verify the presence of the Options Register.
0111 1001 1010 0000 ID0ID1ID0ID1 ReadWrite
Figure 11 --- ID bit write/read table
12 DSCLP/SSCLP-200/300 User's Manual

4.5.2Clock Rate Multiplier
A standard serial port operates at a clock speed of 1.8432 MHz. In order to
achieve higher data rates, Quatech Enhanced Serial Adapters can operate at two times
or four times this standard clock speed. This is controlled by the clock rate multiplier
bits in the Options Register.
Software can determine the UART clock frequency by reading the clock rate
multiplier bits RR1 and RR0 in the Options Register as shown in Figure 12. RR1 and
RR0 can be set by writing to the Options Register if the X2 and X4jumpers (J4-J5) are
all removed. If one of these jumpers is applied, the RR1 and RR0 bits are forced to the
appropriate value. Reading the Options Register will always return the clock rate
multiplier at which the board is operating.
460.8 kbaud7.3728 MHzX401 230.4 kbaud3.6864 MHzX210
115.2 kbaud1.8432 MHz
X1
(default)
00
Maximum Data
Rate
UART Clock
Frequency
Clock Rate
Multiplier
RR0RR1
Figure 12 --- Rate Register bit definition
At powerup and reset, the Options Register is initialized to 0. The
DSCLP-200/300 will thus powerup in the x1 mode with software control of the clock
rate multiplier enabled as long as the X2 and X4 jumpers are not installed.
Software can control high baud rates through a combination of changing the
clock rate multiplier and the UART baud rate divisor. For example, a baud rate of
230.4 kbps could be achieved by setting the clock rate multiplier to X2 mode (or by
applying the X2 jumper) and setting a software application for 115.2 kbps.
The X4 clock multiplier settings
require the presence of 16750 UARTs.
Operation at X4 cannot
be guaranteed with 16550 UARTs.
DSCLP-200/300 User's Manual 13

5Windows Configurations
5.1Windows Millennium
1. After inserting the DSCLP-200/300 for the first time the "Add New Hardware
Wizard" will begin. Select "Search for the best driver for your device.". Check the
"Removable media" and "Specify location" box. Click the "Next" button.
3. Window will locate the proper INF file and copy the file from the CD. Click
the "Next" button.
4. The final dialog screen will verify the file copy from the CD. Click the
"Finish" button.
14 DSCLP/SSCLP-200/300 User's Manual

5.2Windows 2000
1. After inserting a DSCLP-200/300 for the first time, the "Add New Hardware
Wizard will appear at start up. Click the "OK" button.
2. The following dialog box insert the Quatech COM CD (shipped with the
device).
Click the "OK" button.
4. The following dialog box will display the appropriate INF file on the CD in
drive. Click the "OK" button.
5. Window will copy the INF file from the CD and display a final dialog
indication that the process is complete. Click the "Finish" button.
DSCLP-200/300 User's Manual 15