Black Box IC175C, RS-485, IC113C User Manual

CUSTOMER

SUPPORT

INFORMATION

Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [e-mail]

MARCH 2000

IC113C
IC175C

Dual Port RS-232/422/485 Serial Interface

FCC AND IC STATEMENTS, TRADEMARKS

FEDERAL COMMUNICATIONS COMMISSION

AND

INDUSTRY CANADA

RADIO FREQUENCY INTERFERENCE STATEMENTS

This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio communication.
It has been tested and found to comply with the limits for a Class A
computing device in accordance with the specifications in Subpart J of
Part 15 of FCC rules, which are designed to provide reasonable protection
against such interference when the equipment is operated in a commercial
environment. Operation of this equipment in a residential area is likely to
cause interference, in which case the user at his own expense will be required
to take whatever measures may be necessary to correct the interference.

Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.

This digital apparatus does not exceed the Class A limits for radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

TRADEMARKS USED IN THIS MANUAL

AT and IBM are registered trademarks, and XT is a trademark of
International Business Machines Corporation.

Any other trademarks mentioned in this manual are acknowledged to be the property
of the trademark owners.

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

NORMAS OFICIALES MEXICANAS (NOM)

ELECTRICAL SAFETY STATEMENT

INSTRUCCIONES DE SEGURIDAD

1. Todas las instrucciones de seguridad y operación deberán ser leídas antes
de que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo,
cerca de la tina de baño, lavabo, sótano mojado o cerca de una alberca,
etc..

6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales
que sean recomendados por el fabricante.

7. El parato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más
allá a lo descrito en las instrucciones de operación. Todo otro servicio
deberá ser referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama,
sofá, alfombra o superficie similar puede bloquea la ventilación, no se
debe colocar en libreros o gabinetes que impidan el flujo de aire por los
orificios de ventilación.

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de
calor como radiadores, registros de calor, estufas u otros aparatos
(incluyendo amplificadores) que producen calor.

NOM STATEMENT

11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo
del tipo descrito en el instructivo de operación, o como se indique en el
aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y la
polarización del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen
del aparato.

14. El equio eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos de las
lineas de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipo no
sea usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u

B: Objectos han caído o líquido ha sido derramado dentro del

aparato; o

C: El aparato ha sido expuesto a la lluvia; o

D: El aparato parece no operar normalmente o muestra un cambio en su

desempeño; o

E: El aparato ha sido tirado o su cubierta ha sido dañada.

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

Contents

Chapter Page

1. Specifications...................................................................................................1

2. Introduction ....................................................................................................2

2.1 Overview..................................................................................................2

2.2 What’s Included......................................................................................2

2.3 Features ...................................................................................................3

2.4 Technical Description ............................................................................4

3. Address Selection............................................................................................6

4. Option Selection .............................................................................................7

4.1 Port Enable/Disable...............................................................................7

4.2 RS-232 Interface Options .......................................................................9

4.3 RS-422/485 Interface Options.............................................................10

4.4 Line Termination .................................................................................11

5. Installation.....................................................................................................12

Appendix: Circuit-Board Design.......................................................................14

1

CHAPTER 1: Specifications

Protocol — Asynchronous

Speed — IC113C: Up to 115.2 Kbps; IC175C: 460.8 kbps and higher

Operation — RS-232 or RS-485/422, 2- or 4-wire (individually selectable

on each port)

Connectors — (2) DB9M

Communications Chip — IC113C: 16550 UART; IC175C: 16950 UART

MTBF — >150,000 hours

MTTR — <0.25 hours

Materials — Boards are solder mask over bare copper or tin nickel

Operating Temperature — 32° to 122°F (0° to 50°C)

Storage Temperature — -4° to 158°F (-20° to 70°C)

Humidity — 0 to 90% relative humidity, noncondensing

Power — +5 VDC @ 195 mA ±12 V @ 25 mA (derived from PC bus)

Size — 5"W x 7.5 "D (12.7 x 19 cm)

Weight — 0.2 lb. (0.1 kg)

1. Specifications

2

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

2.1 Overview

If you need to operate RS-232, RS-422, or RS-485 devices from your PC, use
the Dual Port RS-232/422/485 Serial Interface. Connect to any device that
uses the RS-232 interface, such as modems, data-entry terminals, and plotters.

This card allows you to configure two RS-232 ports, two RS-422/485 ports, or
one of each. The Dual Port RS-232/422/485 also features greater maximum
distance and allows multi-drop communications.

The card also includes a serial utility disk with Seacom, a DOS interrupt and
driver package. Seacom allows data to be buffered, eliminating data loss in
high-speed data transfers. It also allows more than 4 ports (256 max.) to be
configured and utilized under DOS.

The README file on the serial utility disk contains information about the
latest changes and revisions. To view this file, insert the diskette into drive A
or B and type A:TYPE READ.ME|MORE [ENTER] or B:TYPE
READ.ME|MORE [ENTER].

2.2 What’s Included

Your Serial Interface should come with the following items. If any of these
items are missing or damaged, contact Black Box at 724-746-5500.

(1) Dual Port RS-232/422/485 Serial Interface card,

(2) serial utility software diskettes: (1) for 32-bit Windows®,
(1) for DOS and Windows®3.1x,

This manual

2. Introduction

3

CHAPTER 2: Introduction

2.3 Features

Listed below are the special features your Serial Interface offers.

• Each port is independently addressable.

• Eleven interrupt options, including AT interrupts, for simple integration
into existing systems.

• IRQs (2 [9], 3, 4, 5, 6, 7, 10, 11, 12, and 15) supported.

• IRQs can be shared or individually set for each port.

• Supports Interrupt Sharing—only one interrupt line required for

multiple ports.

• Supports any character set defined by binary notation.

• 16550 UARTs on the IC113C help ensure against data loss. This chip
features programmable baud rate, data format, interrupt control, and a
16-byte FIFO. The IC175C uses 16950 UARTs, which feature a 128-byte
buffer for even better performance.

• Faster baud rates—up to 115.2 Kbps (IC113C) or 460.8 kbps and above
(IC175C).

• Addressable as COM1: through COM4: or any other address up
to 3FF Hex.

• Support for non-standard baud rates available. These baud rates (such as

31.25K or 76.8K baud) are supported by installing a different oscillator at
location Y1. Call Technical Support for more information.

4

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

2.4 Technical Description

The Dual Port RS-232/422/485 Serial Interface utilizes the same 16550 UART
chip found in the IBM®asynchronous adapter. This chip features
programmable baud rate, data format, and interrupt control. Refer to the
IBM Technical Reference for details on programming the chip.

RS-232

The Dual Port RS-232/422/485 Serial Interface meets the RS-232C
specifications and provides an asynchronous serial I/O port. This is the
standard port configuration found in the IBM AT®computer, including the
DB9 style connector.

The table below shows the connector pinouts for ports J1 (port 1) and J2
(port 2) on the Interface while using RS-232.

Pin Number Signal Name Mode

3 Transmit Data (TD) Output RS-232
7 Request To Send (RTS) Output RS-232
4 Data Term Ready (DTR) Output RS-232
5 Ground (GND) ––––––––––––
2 Receive Data (RD) Input RS-232
1 Data Carrier Detect (DCD) Input RS-232
6 Data Set Ready (DSR) Input RS-232
8 Clear To Send (CTS) Input RS-232
9 Ring Indicator (RI) Input RS-232

RS-422

RS-422 allows very long distance communications—4000 feet (about
1219 meters) at 9600 baud—based on use of Category 3, UTP, or better, with
virtually error-free differential drive characteristics. RS-422 signal levels are
the standard electrical specification used in RS-449 and EIA-530. This allows
interfacing with equipment that meets these specifications.

5

CHAPTER 2: Introduction

RS-485

RS-485 is backward-compatible with RS-422; however, it is optimized for
multidrop applications. The output of the RS-422/485 driver is capable of
being active (enabled) or tri-state (disabled). This capability allows multiple
ports to be connected in a multidrop bus and selectively polled. Half-duplex
two-wire communications are possible by connecting TX+ to RX+ and TX- to
RX- in your cable connector. The enable to the driver is connected to the
UART Request To Send (RTS) line for RS-485 communications. This allows
the RS-485 driver to be tri-stated (disabled) when inactive on a multidrop
polled network. The software that you are using must “know how” to enable
the driver when it is answering a poll. Failure to set this jumper correctly can

cause transmitter contention problems, preventing operation by any nodes on
the network.

The table below shows the connector pinouts for ports J1 (port 1) and J2
(port 2) on the Interface while using RS-422/485.

Pin Number Signal Name Mode

4 Transmit Data Pos. (TX+) Output RS-422
3 Transmit Data Neg. (TX-) Output RS-422
6 Req. To Send Pos. (RTS+) Output RS-422
7 Req. To Send Neg. (RTS-) Output RS-422
5 Ground (GND) -------------------­1 Receive Data Pos. (RX+) Input RS-422
2 Receive Data Neg. (RX-) Input RS-422
9 Clear To Send Pos. (CTS+) Input RS-422
8 Clear To Send Neg. (CTS-) Input RS-422

6

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

NOTE

Be sure to set the address selections and jumper options before
installation.

Each serial port on the Dual Port RS-232/422/485 Serial Interface occupies
8 consecutive I/O locations. DIP switch SW1 sets the base address for Port 1,
and DIP switch SW2 sets the address for Port 2. Be careful when selecting the
base address, since some selections conflict with existing PC ports. The
following table shows several examples that usually do not cause a conflict.

Address Binary Switch Position Setting

Hex A9 A0 1 2 3 4 5 6 7

280-287 1010000XXX OFF ON OFF ON ON ON ON
2A0-2A7 1010100XXX OFF ON OFF ON OFF ON ON
2E8-2EF 1011101XXX OFF ON OFF OFF OFF ON OFF
2F8-2FF 1011111XXX OFF ON OFF OFF OFF OFF OFF
3E8-3EF 1111101XXX OFF OFF OFF OFF OFF ON OFF
300-307 1100000XXX OFF OFF ON ON ON ON ON
328-32F 1100101XXX OFF OFF ON ON OFF ON OFF
3F8-3FF 1111111XXX OFF OFF OFF OFF OFF OFF OFF

Typically COM1:=3F8h; COM2:=2F8h; COM3:=3E8h; COM4:=2E8h

The following illustration shows the correlation between the DIP switch
setting and the address bits used to determine the base address. In the figure
below, the address 300 hex through 307 hex is selected (300 hex =11 0000
0XXX in binary representation). Note that setting the switch ON (or closed)
corresponds to a “0” in the address, while leaving it OFF (or open)
corresponds to a “1.”

3. Address Selection

A9 A3

0

1

1 2 3 4 5 6 7 8

EN

ON

OFF

7

CHAPTER 4: Option Selection

NOTE

Be sure to set the address selections and jumper options before
installation.

The board contains several jumper straps for each port which must be set for
proper operation.

4.1 Port Enable/Disable

Each port on the Dual Port RS-232/422/485 can be enabled or disabled with
switch position 8 on the DIP switch. The port is enabled with the switch ON
(or closed) and disabled when OFF (or open). If any port is disabled, be sure
to also disable the interrupt request for that port by removing the IRQ jumper
(see Figure 4-1).

I

NTERFACESELECTION

RS-422/485

To select the RS-422/485 mode of operation, install DIP shunts in sockets
found at E6 and E7. E6 sets Port 1 and E7 sets Port 2.

RS-232

To select the RS-232 mode of operation, install DIP shunts in sockets found
at E5 and E8. E5 sets Port 1 and E8 sets Port 2.

IRQ Selection

Headers E1 and E2 select the interrupt request for each serial port (E1–Port
2, E2–Port 1). If COM1: is selected, this jumper must be on the IRQ4 setting.
If COM2: is selected, this jumper must be on IRQ3.

NOTE

Most communications software applications default COM3: to IRQ4 and
COM4: to IRQ3. This requires the sharing of interrupts between COM1:
and COM3:, and between COM2: and COM4:. While this is the default, it
is not always the best setting. Check your software configuration
instructions to determine the most appropriate IRQ setting.

4. Option Selection

8

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

Figure 4-1. Header E1 and E2 (IRQ selection).

Any two or more ports can share a common IRQ by placing the jumpers on
the same IRQ setting, and setting the appropriate selections at E9 and E10.
Consult your particular software for IRQ selection. If no interrupt is desired,
remove the jumper.

NOTE

IRQ 2 on AT class machines is not available. IRQ 9 is substituted in place
of IRQ 2. To select IRQ 9, place jumper in the IRQ 2 position.

Figure 4-2 shows Headers E9 and E10. “N” indicates the normal, single
interrupt per port mode. The “S” indicates the shared interrupt mode, which
allows more than one port to access a single IRQ. The “M” indicates that the
inclusion of a 1K-ohm pull-down resistor is required on one port when
sharing interrupts. E10 sets Port 1 and E9 sets Port 2.

E1

2/9 3 4 5 7 10 11 12 15

E2

2/9 3 4 5 7 10 11 12 15

9

CHAPTER 4: Option Selection

Figure 4-2. Headers E9 and E10 in Normal Mode.

Set jumpers to “N” for single interrupt mode. This setting is the normal
setting for most applications.

Set jumpers to “S” for shared interrupt mode for all ports sharing an IRQ
except one. Set that port block for “M.” This provides the pull-down resistor
circuit that makes sharing of IRQ’s possible. If you are using more than one Dual

Port RS-232/422/485 Serial Interface or a compatible card in a bus, you should only
have one port set to “M.”

Set jumpers to “S” if you are using more than one Dual Port
RS-232/422/485 in a bus or if you wish to completely remove the pull-down
resistor for hardware compatibility. Setting the board in this configuration
when it is not accompanied by a pull-down resistor will prevent the ports from
triggering an interrupt.

4.2 RS-232 Interface Options

To select the RS-232 mode of operation, install DIP shunts in the sockets
found at E5 and E8. E5 sets Port 1 and E8 sets Port 2. These DIP shunts are
completely independent of each other, allowing the user to select a single­port RS-232 or a single-port RS-422.

There are no modem control options for the RS-232 interface: all control
signals are implemented. If your software requires certain handshaking
signals to be active, then you must connect them either to the device with
which you are communicating or you can satisfy the handshake signal
requirements by connecting pins 7 to 8 (RTS to CTS) and pins 4 to 6 to 1
(DTR to DSR & DCD). Make these connections on the DB9 connector that
connects to each port. Refer to Figure 4-3 when making these connections.
(The table on page 4 lists the RS-232 pinout descriptions.)

N

S

M

10

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

Figure 4-3. DB9 Handshake Loopback connections for RS-232

(shown from rear or cable side of connector).

4.3 RS-422/485 Interface Options

To select the RS-422/485 mode of operation, install DIP shunts in the sockets
found at E6 and E7. E6 sets Port 1 and E7 sets Port 2.

Figure 4-4 shows Headers E3 and E4. Position “A” determines whether the
RS-485 driver is enabled by the UART signal Request To Send (RTS) or always
enabled. With the jumper installed in position “A,” RTS enables the driver.
Removing the jumper enables the driver, regardless of RTS. E4 sets Port 1
and E3 sets Port 2. This jumper should be set to “A” only if you are running
the board in a multidrop polled environment such as RS-485, and you have
software that “knows how to talk” on the RS-485 bus. For normal point-to­point RS-422 (such as terminal emulation), make sure that a jumper at
position “A” is not in place.

Positions “B” and “C” determine whether the board provides a direct ground
connection (as in RS-232 and most RS-422), or a 100-ohm high-impedance
ground. The high-impedance ground is normally used by
RS-485 (and some RS-422) to avoid ground-loop currents with long cables.
Position “B” selects the direct ground, and position “C” selects the 100-ohm
high-impedance ground. “C” should be selected when RS-422/485 operation
is selected.

5 4 3 2 1

9 8 7 6

11

CHAPTER 4: Option Selection

Figure 4-4. Headers E3 and E4, RS-485 Enable/Ground Selection.

4.4 Line Termination

Typically each end of the RS-422/485 bus must have line-terminating
resistors. A 100-ohm resistor is across each RS-422/485 input, and a 1K-ohm
pull-up/pull-down combination biases the receiver inputs. If more than two
RS-485 nodes are configured in a multidrop network, only the nodes at each
end of the bus should have the 100-ohm resistors installed.

A

B

C

12

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

The Dual Port RS-232/422/485 can be installed in any of the PC expansion
slots, except J8 on the original IBM XT®and Portable.

IMPORTANT

You MUST set up the operating system BEFORE you physically install
the Card.

5.1 Software Installation

If you are installing an ISA adapter in DOS, OS/2®, or QNX, please refer to the
appropriate directory on one of the Serial Utilities Disks for instructions.

5.1.1 W

INDOWS

3.1

X

Please refer to the /WINDOWS sub-directory on the Serial Utilities Diskette for
help files and current information on the installation of the Card in this operating
environment.

5.1.2

W

INDOWS

95/98 U

SERS

For the ISA card, run setup on disk two of the Serial Utilities Diskettes before
installing the card. Make note of the resources that Windows assigns the adapter,
and set the adapter to match those resources. Power down the computer and
install the adapter as described in Section 5.2. If you wish to change any resources
assigned to the adapter, refer to the help file installed in the Black Box folder in
the Start, Programs menu.

5.1.3 W

INDOWS

NT

For the ISA card, run setup on disk two of the Serial Utilities Diskettes before
installing the card. After installing the software, refer to the help file that
automatically comes up for installation instructions.

5. Installation

13

CHAPTER 5: Installation

5.2 Hardware Installation

The ISA Card can be installed in any of the PC expansion slots. The Card contains
several jumper straps for each port that you must set for proper operation.

1. Turn off PC power. Disconnect the power cord.

2. Remove the PC case cover.

3. Locate an available slot and remove the blank metal slot cover.

4. Gently insert the Card into the slot. Make sure that the Card is seated
properly.

5. Replace the screw.

6. Replace the cover.

7. Connect the power cord.

Installation is complete.

Self-Test

To perform a self-test on the card, connect the transmit and receive data pins
together. If running 422/485, make sure the plus leads are not connected to
the minus leads. Execute the SLT program provided on the supplied utility
diskette.

14

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

Appendix: Circuit-Board Design

E6

R6

RS-232 PORT 1

U8

PORT1

E4

C
B
A

C
B
A

PORT2

E3

422/485 PORT 1

R7

9
5

E5

R9

U18

RP1

6
1

J1 PORT 1J1 PORT 2

422/485 PORT 2

U13

R8

RP4

U6 U7

R5R4R4

C6

9
5

RS-232 PORT 2

E7E8

U9

C7

PORT1

PORT2

D2

R3

E10E9

U3

PORT2

6
1

C10

U12

C9

P3

P1

15
12
11
10
6
5
4
3
2

PORT1

E1

U11

C8

PORT2

P2

P6

RP2 RP3

15
12
11
10
6
5
4
3

D1

2

E2

R2

PORT2

SW2

C3

PORT1

PORT1

U4 U5

C5

C1

V1

SW1

U2

C2

U1

R1

C1

15

+12V

APPENDIX: Circuit-Board Design

+5V

+12V

B9

P1P1P1

C3

2

3

1

GND

C2

2

3

1

C5

2

3

1

C4

1

C1

1

C8

1

1

C10

+5V

+5V

B3

B29

C6

+5V

2

3

2

3

2

3

2

GND

GND

B1

B31

P1

P1

2

3

GND

1

C7

2

3

1

C9

2

3

-12V

1

-12V

B7

P1

12

+5V

12

+5V

U2

P0P1P2P3P4P5P6

246

A8A6A4

U1

P0P1P2P3P4P5P6

246

A8A6A4

AEN

A11

P1

R2

+5V

20

VDO

R1

+5V

20

VDO

98SW2

19

P=Q

Q0Q1Q2Q3Q4Q5Q6

P7

357

8

11

131517

A3A5A7

A9

AEN

2467531

SW2

SW2

15

1311101214

98SW1

19

P=Q

P7

Q0Q1Q2Q3Q4Q5Q6

8

357

11

131517

A3A5A7

A9

AEN

2467531

SW1

SW1

15

1311101214

A9A8A7A6A5A4A3

A22

A23

A24

A25

A26

P1P1P1P1P1P1P1

BRD/

BWR/

CS1

CS2

DISTR

DISTR

DOSTR

BD1

BD2

BD3

BD4

BD5

BD6

D1

12

R3

13579

E1

246

IRQ2

IRQ3

B4

GND

ADS

RCLK

DOSTR

8

33323431242315

DTR1

BD7

1

2

GND

8

1012141618

IRQ4

B25

RD1

CTS1

SIN

CTS

RTS

OUT1

RTS1

SHEET 2

1
2
3
4

11

131517

IRQ5

B24

SHEET 2

RI1

DSR1

DCD1

BA0

RI

A0A1A2

DSR

DCD

OUT2

CSOUT

DDIS

BAUDOUT
30

10

U6

D2

E9

12

E2

IRQ10

D3

B23

BA1

98

IRQ12

BA2

26

INTRPT

SOUT

11

TD1

SHEET 2

13579

246

D5

8250A

74LS125A

R4

1

2

GND

8

1012141618

IRQ7

1
2
3
4

11

131517

IRQ11

B21D4D6

E10

IRQ15

SHEET 2

RI2

RD2

CTS2

DSR2

DCD2

BA0

BA1

BWR/

DOSTR

BD6

HC244

A30

GND

ADS

DOSTR

8

33323431242315

DTR2

BD7

RP1

RP1

RP1

U3

A29

P1

BA2

26

RI

A0A1A2

SIN

CTS

DSR

DCD

RCLK

8250A

RTS

OUT1

OUT2

CSOUT

DDIS

BAUDOUT

INTRPT

SOUT

11

30

TD2

RTS2

SHEET 2

SHEET 2

4

2

6

13

1211

U6

74LS125A

BWR/

BRD/

GND

10

VDO/VSS

19

+5V

20

975

3

Y1Y2Y3

Y4

VDO

U12

HC244

A1A2A3

A4

G

DIR

G

1

11

131517

19

GND

BRD

SHEET 1

D0D1D2D3D4D5D6

RD/

WR/

A9A8A7A6A5A4A3

B13

B14

P1

P1

P1P1P1P1P1P1P1P1P1P1P1P1P2P2P1P2P2

+5V

1617351213142221191825910363738392827

XTAL1

OUT

VDO

U4

Y1

TXCO

VDO

NC

VSS

20

40

114

78

+5V

GND

BD1

BD2

BD3

BD4

BD5

BD6

BD7

GND

11

1716151413

12

18 BD0

10

B2B3B4B5B6B7B8

B1

VSS

A2A3A4A5A6A7A8

A1

3456789

2

D7

BRESET

+5V

MR

CS0

XTAL2

VSS

D0D1D2D3D4D5D6D7DTR

1234567

GND

BD0

74LS245

A2

BRD/

BRESET

+5V

1617351213142221191825910363738392827

MR

CS0

CS1

CS2

XTAL1

XTAL2

DISTR

DISTR

U5

VSS

D0D1D2D3D4D5D6D7DTR

VDO

1234567

20

GND

1

10

VSS

P>Q

74LS682

Q7

9

121416

18

GND

SW2

SW2

SW2

SW2

GND

1

10

VSS

P>Q

74LS682

Q7

9

121416

18

GND

SW1

SW1

SW1

SW1

A27

A28

40

+5V

GND

BD0

BD1

BD2

BD3

BD4

BD5

1

1

GND

74LS125A

1

23

+5V

74LS125A

BA0

BA1

BA2

BRESET

+5V

181614

12

20

Y1Y2Y3

Y4

U3

VDO/VSS

A1A2A3

A4

G

246

8

1

A0A1A2

RESET

B2

A31

1

U6

SW2

16

GND

GND

56

4

U6

2

SW1

R5

1

16

+5V

GND

P1P1P1

16

DUAL PORT RS-232↔422/485 SERIAL INTERFACE

2

4

10

12

74LS04

74LS04

U7

U7

11

13

GND

GND

21

R6

C

GND2/

J2 5

U9-3

+5V

3

16

1Y2Y3Y

VDO

U9

1A1B2A2B3A3B4A

216

7

8

3

4

7

7

5

RP2

RP2

8

6

7

5

4

2

U8-15

+5V

1514131211

U8

VEE+ VDO

23456

1

+12V

74LS04

74LS04

U7

SPARE GATES

+5V

1

RP4

6

GND

246

E4

135
A

B

8

U7

74LS04

9

SHEET 1

SHEET 1

RI1

RI2

SHEET 2

SHEET 2

SHEET 1

SHEET 2

SHEET 1

SHEET 2

SHEET 1

TD1

RTS1

DTR1

U8-11

U8-13

10169

MC145406

VEE- VSS

8

7

-12V GND

SHEET 2

U10-3

U10-11

368

11

OUTA

OUTB

OUTC

OUTD

U10

V+

21549

14

+5V

MC1489

ENA

INA

ENB

INB

ENC

INC

END

IND

GND

7

101213

GND

+5V

16

VDO

U13

1Y1Z2Y2Z3Y3Z4Y

236

1107

1A2A3A

5

9158

11

SHEET 1

TD2

RTS2

4A

4Z

EN1

14

13412

U7

1

3

GND

21

C

GND1/

J1 5

GND

VSS

EN2

+5V

1

R7

RP4

8

GND

246

E3

135
A

B

6

U7

74LS04

5

RP3

1

RP3

1

RP3

1

RP3

1

75174

+5V GND

RP4

1

RP4

1

RP4

1

RP4

1

U9-5

10 5914

+5V

1

SHEET 2

DTR2

314

SHEET 1

U11-13

413

RP1

5

SHEET 2

512

1

RP1

3

SHEET 2

U11-11

MC145406

VEE- VSS

611

710

89

-12V GND

SHEET 2

U9-11

U9-13

8

11

13

4Y

VSS GND

75173

4B

EN

EN

15412

U11-15

+5V

3

2

16

RP2

4

15

RP2

U11

1

VEE+ VDO

2

1

+12V

R9

12

-12V

2423222120191817161514

E5

RS-232

123456789

RD1/

DSR1/

269

J1J1J1

R8

SHEET 2

U8-11

U8-15

U8-13

U10-11

13

E6

101112

RI1/

RTS1/

7

J1

U9-5

2423222120191817161514

123456789

RD1

TD1/

CTS1/

DTR1/

DCD1/

813

4

J1J1J1

J1

SHEET 2

U9-3

101112

CTS1

GND

13

E7

RS-422

DSR1

DCD1

SHEET 1

U9-11

2423222120191817161514

123456789

RD2

RI2/

RD2/

RTS2/

DSR2/

269

7

J2J2J2

J2

SHEET 2

U9-13

101112

CTS2

GND

13

RS-422

DSR2

DCD2

SHEET 1

2423222120191817161514

E8

123456789

CTS2/

DCD2/

813

J2J2J2

SHEET 2

U10-3

U11-11

U11-15

U11-13

13

RS-232

101112

TD2/

DTR2/

4

J2

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