CIO-COM422

FEATURES
RS422, RS232 or Current loop Serial Interface.
COM1, COM2, COM3 or COM4.
5, 6, 7 or 8 bit character length, even, odd or no parity.
RTS/CTS/DTR handshaking.
56K Baud RS232 or RS422, 4.8 K Baud Current Loop.
CIO-COM422/550 adds 16 byte data buffer.
The CIO-COM422 is a 100% IBM Asynch adapter compatible
serial interface. It is also compatible with MetraByte's COM422.
The CIO-COM422 adds one EIA compliant RS232 or RS422 port
to your computer. The RS422 interface supports longer transmission lines (up to 1.2 Kilometers) and is often the interface ofchoice for instruments.

CIO-DUAL422

FEATURES
Dual RS422 Serial Interfaces.
COM1, COM2, COM3 or COM4.
5, 6, 7 or 8 bit character length, even, odd or no parity.
RTS/CTS handshaking.
56K Baud RS422.
CIO-DUAL422/550 adds 16 byte data buffer per port.
RS422 is the serial communication standard endorsed by the EIA
to replace RS232. Supporting longer transmission lines due torelatively noise immune differential drivers, the RS422 standard
is designed with industrial instrument and data acquisition module
communication in mind.
The CIO-COM422 is a simple way to upgrade your computer fromstandard ports to state of the art RS422 serial interfaces.

CIO-COM485

FEATURES
RS485 Serial Interface, software enabled Tx & Rx
Network up to 4000 feet.
COM1, COM2, COM3 or COM4.
56K Baud.
16550 COM chip has 16 byte data buffer.
Designed for low-cost serial networks, the CIO-COM485 places
the transmit and receive transceivers under software control. The
RS485 standard allows for multiple transmitters as well as multiple receivers.
Individual RS485 devices may be located as far as 4000 feet fromeach other. The interfaces are not isolated so must share acommon ground. The interface lines are fused to protect thecomputer should there be a ground fault between networked
RS485 devices.

STANDARD 9 and 25 PIN CONNECTORSThe CIO-COM422 combines an RS232 andan RS422 interface with a single communications port.
RS232 is commonly a 25 pinconnector,
while RS422
is a 9 pin connector.
SIG GND

1RTS+

2

RTS-

3

TX DATA +4

TX DATA -5NC

13NC

12-XMIT CL

11NC

10+XMIT CL

9CARRIER DET

8SIG GND

7DATA SET READY

6CLEAR TO SEND

5EIA RTS4EIA RX DATA

3EIA TX DATA

2NC

16CTS-7CTS+

8RX DATA +9RX DATA -25-RCV CL DATA

24NC23NC

22

EIA RI

21NC

20EIA DTR

19NC

18+RCV CL DATA

17NC16NC15NC14NC

The pin assignments
shown here
conform tothe RS232 andRS422 standards.

The CIO-DUAL422 combines a pair ofcommunications ports each with RS422
standard interfaces. Each COM
port uses one of the
9 pin connectors
shown here.
SIG GND

1RTS+

2RTS-

3TX DATA +4TX DATA -5SIG GND

1RTS+

2RTS-

3

TX DATA +4TX DATA -56CTS-

7CTS+8RX DATA +9RX DATA -

6CTS-

7CTS+

8RX DATA +9RX DATA -VIEW FROM REAR OF PC
VIEW FROM REAR OF PC

BASE ADDRESS
Personal Computer COM1, 2, 3 or 4 ports are assigned through a
combination of base address
Base Address Switch
and interrupt level. Each COM
Set for COM1 or COM2
board has one base address
9 8 7 6 5 4 3C O M 1 switch for each COM chip.
S W HEX
A9A8A7A6A5A4A3200100804020108(3F8)All Do wnwhich is 19876543COM422
Protocol Select
There are 5 possible protocol selections available
through the protocol select switch.

COM22F8SW8 up for
COM2To operate correctly with personal computer COM# software drivers, the guidelines
for both address and interrupt
level should be adhered to.

Protocol Selection Switch
6 5 4 3 2 1RS-232 with STD
control signals
6 5 4 3 2 1RS-232 without STD
control signals

1) Standard RS232 withRTS, DTR & CTS.
6 5 4 3 2 12) RS232 without RTS,
DTR & CTS.
3) Current Loop

Current Loop

6 5 4 3 2 1RS-422 with RTSand CTS enabled

4) RS422 with RTS andCTS control signals.
6 5 4 3 2 15) RS422 without RTS &CTS.

RS-422 without
CTS or DTS signals

Since each COM
chip may be configured as COM 1,2, 3 or 4, the assignment of COM
ports to connectors is flexible.

The CIO-COM485 is equipped with two
DB9 connectors for RS485 standard 9 pin
connectors andcables. The RS485
standard allows
multiple transmitters and receivers
on a single communications cable.
SIG GND

1NC

2

Fused GND

3

TX/RX +4

TX/RX -5

SIG GND

1NC

2

Fused GND

3TX/RX +4TX/RX -Each connector
carries the communications signals of a complete
RS422 interface.

56+5V

7NC

8TX/RX +9TX/RX -6+5V

7NC

8TX/RX +9TX/RX -VIEW FROM REAR OF PC

The CIO-COM485
facilitates interconnection by providing two connectors wired in parallel to the single
communications
port. In this manner, standard cables
may be used without the addition ofa 'T'.

INTERRUPT LEVEL JUMPER
Communications software such as the standard COM drivers
included with DOS andWindows use interrupt
service routines assigned to specific interruptnumbers.
Choose the correct interrupt number by setting the jumper on theCIO-COM board.

CIO-DUAL422
CTS/RTS Enable
RS422 may be used with or without hardware handshaking. The Clear To Send(CTS) and RTS signal lines may be enabled or disabled by setting a jumper on
the CIO-DUAL422.

SPECIFICATIONS
ProtocolCOM Ports
UART (Standard)
UART (/550 models)Power Consumption
EnvironmentalSize

CIO-COM422
CIO-DUAL422
CIO-COM485
RS232 & RS422
RS422
RS485
One
TwoOne
16450
16450
16550
16550
16550
N/A+5V @ 500mA, -12V @ 30mA, +12V @ 30mAOperating Temp 0-50C, Storage -55 to 125C
Height 4.25" X Length 5" @ 4.5 oz.

ORDERING GUIDERS232 or RS422 Serial Interface, Single Com Port
Same but with 16550 COM chip
RS422 Serial Interfaces (Two), Dual Com Ports
Same but with 16550 COM chip
RS485 Serial Interface, Single Com Port

CIO-COM422
CIO-COM422/550
CIO-DUAL422
CIO-DUAL422/550
CIO-COM485

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