Black Box RS-422 User manual

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: [email protected]
CUSTOMER
SUPPORT
INFORMATION
JUNE 2000
SW421A-R2
SW422A-R2
RS-422 Code-Operated Switches
TEXT
TRANSPARENT
GRAPHICS
MODE
RESET ST LO
COS/4

RS-422 CODE-OPERATED SWITCHES
2
TRADEMARKS USED IN THIS MANUAL
DEC and VT100 are trademarks of Digital Equipment Corporation.
GW-Basic is a registered trademark of Microsoft Corporation.
HP is a registered trademark of Hewlett-Packard.
Wyse is a registered trademark of Wyse Technology.
Any other trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.

RS-422 CODE-OPERATED SWITCHES
3
1. Specifications
Data Rates — 300, 1200, 2400, 4800, 9600, 19,200, 38,400, 76,800 bps
Interface — RS-422/V.11, full duplex, asynchronous
RS-422 Circuits Supported
Pin # Description Pin # Description
12 Control in low 18 Data in high
13 Control in high 19 Data in low
14 Control out high 24 Data out high
15 Control out low 25 Data out low
Connectors — COS/4: (5) Female DB25 (master port and four subordinate ports); COS/8: (9)
Female DB25 (master port and eight subordinate ports); 5 to 8 bit, asynchronous
Indicators — LOCKOUT and SWITCH TIME LED indicators. Segment display for CHANNEL
SELECTED
Controls — External: Vertical switch (mode switch), pushbutton reset; Internal: Baud rate (300
to 76,800 bps) and format selectable; DTE/DCE configuration switch for each port
(non-functional); Auto Timeout (2.5 min., 5 min, 10 min., or infinite) switch-
selectable; Arming selectable, switch-selectable
Addressing — Two-digit code as follows: First digit is switch-selectable, initiates Switch Time—
factory setting is EOT (Ctrl D), (Hex 04), (Decimal 4). Second digit assigns
channel, Hex 30–37 selects port 0–7. Any channel can switch the channel when the
unit is in Switch Time (unless disabled by SW6 positions 1–4). The arming and
switching code is stripped by the Code-Operated Switch. The arming character can
pass as data in Graphics mode.
Enclosure — High-impact plastic
Operating Temperature — 32 to 122°F (0 to 50°C)
Storage Temperature — -4 to +158°F (-20 to +70°C)
Humidity Tolerance — 15 to 95%, noncondensing
Power — 115/230 VAC (switch-selectable), 60/50 Hz, 11 watts
Size — 12.3" x 11.8" x 2.5" (31.2 x 30 x 6.4 cm)
Weight — 8 lb. (3.6 kg)

RS-422 CODE-OPERATED SWITCHES
4
2. Introduction
2.1 Description
The Code-Operated Switch 422 (COS) is an asynchronous RS-422 switch. By sending codes to the master port, you
can select subordinate ports. The master device (CPU or terminal) selects any of the other ports (printers,
modems, or terminals, for example) by transmitting the proper arming and switching codes. The communications
link can also be made by any of the subordinate devices by transmitting their own channel address code while the
switch is in the Switch Time mode. Once the communications link is established, all other ports are locked out. The
ports remain locked out until either the master port or the selected subordinate port sends an arming character.
Reception of the arming character causes the COS to break all switched connections (leads 2, TD, and 3, RD,
control in and control out—user-selectable) between the master and subordinate port and puts the unit back in
Switch Time mode.
Signal ground (pin 7) is tied to chassis ground (pin 1) on each port. All ports have female DB25 connectors.
Configuration switches on all ports allow configuration to a DTE or DCE port. The devices also have switches to
select the baud rate and word format (parity, character length, and number of stop bits).
Figure 2-1 shows a network involving various peripherals. The computer (or terminal) selects which device it wishes
to communicate with by transmitting the proper arming and switching code (0 through 3 for the 4-port model, 0
through 7 for the 8-port model).
NOTE: Models with RS-232 ports are available as part numbers SW853A and SW854A. The COS can also be
specially ordered with some RS-422 and some RS-232 ports. These units are configured at the factory at the time the
order is placed. When you receive a specially ordered COS, make sure the configuration matches your order.
Figure 2-1. Typical Application.
Industrial Controller
Data Collection Panel
Serial Code-
Operated
Switch (4-Port)
Digital Analog Converter
Lathe
PC

RS-422 CODE-OPERATED SWITCHES
5
2.2 Board Layout
*W5 on the COS/4 is the same as W1 on the COS/8.
Figure 2-2. Component Layout.
These switches are for COS-8 RS-232 only
W1 = COS/8*
SW5
115
SW4 SW3 SW2
SW1
W1
SW6
SW9
SW7
SW10 SW8
LOCKSWT
C
B
A
W4
40167B

RS-422 CODE-OPERATED SWITCHES
6
3. Installation
3.1 General
Installation of the COS is a matter of connecting the modem and terminal connectors to the proper
communications equipment using the interface connectors.
When viewing the COS from the rear, the leftmost connector is the Master connector. The channel connectors are
numbered from left to right 0, 1, 2, 3 (4, 5, 6, and 7 also for COS/8).
The COS directs data flow between the master port and whichever subordinate port that has been specified in the
command sequence.
Determine if any internal switches must be reconfigured to match your particular application. The unit’s internal
DIP switches are factory-preset to the following parameters:
Baud Rate: 9600 bps
Word Format: 8 data bits, 1 stop bit, and parity disabled
Auto Timeout: Disabled
Arming Character: 04 Hex (EOT), CTRL D
All Serial Ports: DCE with DSR, DTR Control
3.2 Switch Settings
CAUTION
If any internal DIP-switch settings must be changed, be certain that power is
disconnected from the unit before changing settings.
Refer to Figure 2-2 for the location of the switches. In the following switch descriptions, closed is abbreviated as C
and open is abbreviated as O.
3.2.1 SWITCH SW6
Switch Position
1 Open = Disables the slave’s ability to put the unit into switch time.
2 Open = Disables the master’s ability to put the unit into switch time.
3 Open = Disables the master’s ability to switch from switch time to channel.
4 Open = Disables the slave’s ability to switch from switch time to channel.
Close 5 Closed = 2.5-minute auto timeout.
only 6 Closed = 5-minute auto timeout.
one 7 Closed = 10-minute auto timeout.
8 Closed = Timeout is infinite.
{

RS-422 CODE-OPERATED SWITCHES
7
Figure 3-1. Port Configuration Switches.
Typical Switch Configuration for DCE Typical Switch Configuration for DTE
Switch A Close 6 and 7 Switch A Close 5 and 8
Switch B Close 1 and 4 Switch B Close 2 and 3
Note that positions 6, 7, and 8 on Switch B may be selected to assert RTS or CTS high or to tie RTS directly to CTS.
Switch 5 may be used to assert CD high.
RS-422 operates independently of port switch settings.
DTE is used if connecting to a terminal.
DCE is used if connecting to a modem.
CONTROL
IN
CONTROL
OUT
DATA
IN
DATA
OUT
CONTROL IN - 12
CONTROL IN + 13
CONTROL OUT + 14
CONTROL OUT - 15
DATA IN + 18
DATA IN - 19
DATA OUT + 24
DATA OUT - 25
SIGNAL PIN #
RS-422 PORT
DATA
OUT
PIN # SIGNAL
RS-232 PORT
2 TXD
3 RXD
SWITCH A
1
2
3
4
5
6
7
8
SWITCH B
1
2
3
4
5
6
7
8
6 DSR
20 DTR
7 SIG GND
1 FRAME GND
8CD
4 RTS
5 CTS
VCC
DATA
IN
CONTROL
OUT
CONTROL
IN

RS-422 CODE-OPERATED SWITCHES
8
3.2.2 SWITCH SW7
Switch Position
1 Open = Even Parity
1 Closed = Odd Parity
Position 2 Position 3 Word Length
Closed Closed 5 bits
Open Closed 6 bits
Closed Open 7 bits
Open Open 8 bits
4 Open = 2 stop bits
4 Closed = 1 stop bit
5 Open = Parity Disable
5 Closed = Parity Enable
6 Always Open
7 See graphics mode description, Section 4.6.3.
8 See graphics mode description, Section 4.6.3.
3.2.3 SWITCH SW8 ARMING CODE SETTINGS
EOT is the factory-default arming character.
ASCII codes 1 through 6 are the port address codes.
C = Closed (Off)
O = Open (On)
Arming Characters Arming Character Switch Positions
LSB MSB
ASCII CTRL Hex Decimal 1 2 3 4 5 6 7 8
NUL@00 0 CCCCCCCC
SOHA 01 1 OCCCCCCC
STXB 02 2 COCCCCCC
ETXC 03 3 OOCCCCCC
EOT D 04 4 C C O C C C C C
ENQ E 05 5 O C O C C C C C
ACK F 06 6 C O O C C C C C
BEL G 07 7 O O O C C C C C
BS H08 8 CCCOCCCC
HT I 09 9 OCCOCCCC
LF J 0A 10 C O C O C C C C
VT K 0B 11 O O C O C C C C
FF L 0C 12 C C O O C C C C
CR M 0D 13 O C O O C C C C
SO N 0E 14 C O O O C C C C
SI O 0F 15 O O O O C C C C

RS-422 CODE-OPERATED SWITCHES
9
Arming Characters Arming Character Switch Positions
LSB MSB
ASCII CTRL Hex Decimal 1 2 3 4 5 6 7 8
DLE P 10 16 C C C C O C C C
DC1 Q 11 17 O C C C O C C C
DC2 R 12 18 C O C C O C C C
DC3 S 13 19 O O C C O C C C
DC4 T 14 20 C C O C O C C C
NAK U 15 21 O C O C O C C C
SYN V 16 22 C O O C O C C C
ETB W 17 23 O O O C O C C C
CAN X 18 24 C C C O O C C C
EM Y 19 25 O C C O O C C C
SUB Z 1A 26 C O C O O C C C
ESC [ 1B 27 O O C O O C C C
FS \ 1C 28 C C O O O C C C
GS ] 1D 29 O C O O O C C C
RS ^ 1E 30 C O O O O C C C
US _ 1F 31 O O O O O C C C
SPACE 20 32 C C C C C O C C
!2133OCCCCOCC
"2234COCCCOCC
#2335OOCCCOCC
$2436CCOCCOCC
%2537OCOCCOCC
&2638COOCCOCC
'2739OOOCCOCC
(2840CCCOCOCC
)2941OCCOCOCC
.2A42COCOCOCC
+2B43OOCOCOCC
,2C44CCOOCOCC
-2D45OCOOCOCC
.2E46COOOCOCC
/2F47OOOOCOCC
03048CCCCOOCC
13149OCCCOOCC
23250COCCOOCC
33351OOCCOOCC
43452CCOCOOCC
53553OCOCOOCC
63654COOCOOCC
73755OOOCOOCC
83856CCCOOOCC
93957OCCOOOCC
:3A58COCOOOCC
;3B59OOCOOOCC

RS-422 CODE-OPERATED SWITCHES
10
Arming Characters Arming Character Switch Positions
LSB MSB
ASCII CTRL Hex Decimal 1 2 3 4 5 6 7 8
<3C60CCOOOOCC
=3D61OCOOOOCC
>3E62COOOOOCC
?3F63OOOOOOCC
@4064CCCCCCOC
A4165OCCCCCOC
B4266COCCCCOC
C4367OOCCCCOC
D4468CCOCCCOC
E4569OCOCCCOC
F4670COOCCCOC
G4771OOOCCCOC
H4872CCCOCCOC
I4973OCCOCCOC
J4A74COCOCCOC
K4B75OOCOCCOC
L4C76CCOOCCOC
M4D77OCOOCCOC
N4E78COOOCCOC
O4F79OOOOCCOC
P5080CCCCOCOC
Q5181OCCCOCOC
R5282COCCOCOC
S5383OOCCOCOC
T5484CCOCOCOC
U5585OCOCOCOC
V5686COOCOCOC
W5787OOOCOCOC
X5888CCCOOCOC
Y5989OCCOOCOC
Z5A90COCOOCOC
[5B91OOCOOCOC
5C 92 C C O O O C O C
]5D93OCOOOCOC
5E94 COOOOCOC
¨5F95OOOOOCOC
-6096CCCCCOOC
a6197OCCCCOOC
b6298COCCCOOC
c6399OOCCCOOC
d 64 100 C C O C C O O C
e 65 101 O C O C C O O C
f 66 102 C O O C C O O C
g 67 103 O O O C C O O C