Black Box S-COS/2 User manual

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]
© Copyright 1993. Black Box Corporation. All rights reserved.

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CUSTOMER
SUPPORT
INFORMATION
NOVEMBER 1993
SW281A
Serial Code Operated Switch
S-COS/2
MODE 1
DISABLE
MODE 2
S-COS/2
AB
SWITCH TIME
MODE
COS A B

SERIAL CODE OPERATED SWITCH S-COS/2
1
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
Any trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.

SERIAL CODE OPERATED SWITCH S-COS/2
2
INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement)
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 aparato 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.
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 equipo 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.

SERIAL CODE OPERATED SWITCH S-COS/2
3
Contents
Chapter Page
1. Specifications................................................................................................................................................4
2. Introduction .................................................................................................................................................5
3. Installation....................................................................................................................................................6
3.1 General...........................................................................................................................................6
3.2 Switch Settings ...............................................................................................................................6
3.3 Jumpers ........................................................................................................................................11
3.4 Installation Procedure.................................................................................................................11
4. Operation ...................................................................................................................................................12
4.1 Modes of Operation ....................................................................................................................12
4.2 Manual Override .........................................................................................................................13
4.3 Switch SW3 Arming Code Settings.............................................................................................13

SERIAL CODE OPERATED SWITCH S-COS/2
4
1. Specifications
Interface — RS232/V.24, full duplex, asynchronous
Connectors — (3) DB25 female
Coding — 5 to 8 bit, asynchronous
Controls — External — (2) toggle switches (modes and manual override)
Internal — Baud rate and format
DTE/DCE configuration switch for each port
Auto Timeout
Arming Character
Indicators — (3) LEDs: Channel A, Channel B, and SWITCH TIME MODE
Addressing — Two-digit code:
First digit is switch-selectable, initiates Switch Time Mode—factory
setting is EOT (Ctrl D, Hex 04)
Second digit assigns channel; Hex 31H-32H locks out the other
channel
No port is selected in the Switch Time mode
Data Rate — 75, 300, 600, 1200, 2400, 4800, 9600, 19,200 bps
Power — 115 VAC, 60Hz, 11 watts
Enclosure — High-impact plastic
Humidity — 15% to 95% noncondensing
Temperature — Operating — 32 to 122°F (0 to 50°C)
Storage — -4 to +158°F (-20 to +70°C)
Size — 2.25"H x 8.75"W x 11.25"D (5.7 cm x 22.2 x 28.6 )
Weight — 2.6 lb. (1.2 kg)
Circuits Supported
Pin Name Description
1 FG Chassis Ground, wired straight through
2 TD DTE/DCE switched for each channel
3 RD DTE/DCE switched selectable for each channel
4 RTS Switch-selected to be pulled up or tied to pin 5
5 CTS Switch-selected to be pulled up or tied to pin 4
6 DSR DTE/DCE switched for each channel
7 SG Signal return, wired straight through
8 DCD Received-line signal detector, switch-selected to be pulled up or not to be
pulled up
20 DTR DET/DCE switch selectable for each channel
Pins 6 and 20 (control in and control out) are switched by the S-COS/2.
Pin 4 or 8 can be selected for control in or control out.

SERIAL CODE OPERATED SWITCH S-COS/2
5
2. Introduction
The Code Operated Switch is an asynchronous RS-232C switch. Under code control, a master port can
select subordinate ports. The master device (a CPU or terminal) selects any of the other ports (printers,
modems, or terminals) by transmitting the proper arming and switching code.
Any of the subordinate devices can also make the communications link by transmitting their own
channel address codes 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 S-COS/2 to break all switched
connections—leads 2 (TD), 3 (RD), control in, and control out—between the master and subordinate
port. The unit then resumes Switch Time mode.
All signal grounds (pin 7) are tied together, as are all chassis grounds (pin 1). All of the ports have
DB25 female connectors. Switches for each port allow DTE or DCE configuration. There are also
switches to select baud rate and word format (parity, character length, and number of stop bits).
The computer selects which device to communicate with by transmitting the proper arming and
switching code.
Figure 1. Typical Application.
PC
SERIAL CODE
OPERATED
SWITCH PRINTER
MODEM

SERIAL CODE OPERATED SWITCH S-COS/2
6
3. Installation
3.1 General
Installation of the Code Operated Switch is a matter of connecting the MODEM and TERMINAL
connectors to the proper communications equipment using the RS-232 connectors.
All ports have DB25 female connectors normally configured as DCE. With internal DIP switches,
you can individually reconfigure each port for DTE operation if necessary.
The Master port is the only port to enable port selection.
3.2 Switch Settings
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
CAUTION
Be certain that power is disconnected from the unit while changing any DIP switch
settings.
Refer to Figure 2 on page 7 for the location of the internal switches.

SERIAL CODE OPERATED SWITCH S-COS/2
7
S1 — WORD FORMAT
The parameters set by this switch will be the same for the entire network.
Switch
Position Status Description
1 Open Even Parity
Closed Odd Parity
Position 2 Position 3
Closed Closed 5-Bit Word Length
Open Closed 6-Bit Word Length
Closed Open 7-Bit Word Length
Open Open 8-Bit Word Length
4 Open 2 Stop Bits
Closed 1 Stop Bit
5 Open Parity Disable
Closed Parity Enable
6 Always Open
7 Always Closed
8 Always Open
S2 — BAUD RATE
Close only one position to set the baud rate.
Position Closed Baud Rate
1 75 bps
2 300 bps
3 600 bps
4 1,200 bps
5 2,400 bps
6 4,800 bps
7 9,600 bps
8 19,200 bps

SERIAL CODE OPERATED SWITCH S-COS/2
8
Figure 2. Component Layout.
CHANNEL B MASTER CHANNEL A
S4A
S4B
S5A
S5B
S6A
S6B
S1
S2
S3
S7
OPEN OPEN OPEN OPEN
OPEN
OPEN
OPEN
OPEN
OPEN OPEN
AAB
B
CAS
SWT
12345678
12345678
87654321
1234
1234567812345678 1234567812345678 1234567812345678
J2
J1

SERIAL CODE OPERATED SWITCH S-COS/2
9
Figure 3. Port-Configuration Switches.
S3 — ARMING CHARACTER CODE
The S-COS/2 is set at the factory for an EOT (04) arming code. If you need to change the code, refer to
Section 4.3 for a listing of codes and the appropriate switch settings. The arming character must never
appear in the normal data unless the vertical 3-position toggle switch (MODE 1, DISABLE, MODE 2) is
set to DISABLE or
MODE 2.
S4A, S4B, S5A, S5B, S6A, AND S6B — PORT CONFIGURATION
The port-configuration switches set the port configurations for the Master and Channel ports as follows:
• S4A and S4B are for the Channel A port
• S5A and S5B are for the Master port
• S6A and S6B are for the Channel B port
Refer to Figure 3 for a diagram of these switches.
Switch 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.
DTE AND DCE
When connecting two devices together with a straight-pinned cable, the devices must be opposites
(one DTE, one DCE). Thus the S-COS/2’s port must be configured to be the opposite of the
connecting device.
SWITCH A
CONTROL OUT
CONTROL IN
DATA OUT
DATA IN
+ V
7 SIG GND
1 FRAME GND
2 TXD
3 RXD
6 DSR
20 DTR
8 CD
4 RTS
5 CTS
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
RS-232 PORT
SWITCH B

SERIAL CODE OPERATED SWITCH S-COS/2
10
A DTE (Data Terminal Equipment) device outputs data on pin 2 and receives data in on pin 3. Its
control output pins are (4) RTS and (20) DTR. Its control input pins are (5) CTS, (6) DSR and (8)
DCD. Terminals, personal computers, and DEC™computers are all examples of DTE devices.
Typical Configuration for the S-COS/2 to Appear as DTE
Switch Positions Closed
A 5 and 8
B 2 and 3
A DCE (Data Communication Equipment) device is the opposite of DTE. It outputs data on pin 3 and
receives data in on pin 2. Its control output pins are 5 (CTS), 6 (DSR) and 8 (DCD). Modems, HP®
computers, and DG computers are all examples of DCE devices.
Typical Configuration for the S-COS/2 to Appear as DCE
Switch Positions Closed
A 6 and 7
B 1 and 4
S7 — MODE 2 TIMEOUT
This 4-position DIP selects the amount of timeout delay when the S-COS/2 is in Mode operation (see
Section 4.1 on page 11). Close only one position of this switch at a time.
When the value for delay time is expressed in hex words, you can convert the figure to real time by using
the following equation:
((1/Y) ×(X))/0.2 = T
Where:
Y = baud rate
X = word delay
T = time in seconds
Examples:
• A 100-hex-word delay at 9600 baud equals a 52-millisecond delay.
• A 100-hex-word delay at 4800 baud equals a 104-millisecond delay.
• A 50-hex-word delay at 9600 baud equals a 26-millisecond delay.
• A 50-hex-word delay at 4800 baud equals a 52-millisecond delay.
Timeout Delay when the S-COS/2 is in Mode Operation
Position Closed Timeout Period
1 5 hex words
2 25 hex words
3 50 hex words
4 100 hex words

SERIAL CODE OPERATED SWITCH S-COS/2
11
3.3 Jumpers
J1 — BREAKS
When jumper J1 is installed, the S-COS/2 will pass breaks. If jumper J1 is not installed, the S-COS/2 will
not pass breaks.
The S-COS/2 generates a break signal as follows: When the master or slave port UART receives a break,
the UART raises pin 14 to a logical 1 (this represents a framing error to the UART). The UART thinks it
has received a character with an invalid stop bit. The raising of the framing-error pin starts the
multivibrator timing circuit that sends a constant space signal for approximately 257 milliseconds to the
connected output port. This duration represents a break.
Once the break condition has occured, multiple breaks cannot be sent, because the framing-error pin
on the UART cannot be reset, and the UART does not know whether the next character received is valid
data or not. To reset the framing-error pin on the UART, put the S-COS/2 into Switch Time Mode (see
Section 4.1). Then reconnect the other port or power off and on.
Figure 4. J2 Jumper Settings.
J2 — MODE DEFAULT SETTING
Jumper J2 determines the default mode when the S-COS/2 is powered up or reset. See Figure 4 for the
available settings and results.
3.4 Installation Procedure
1. Remove the cover from the S-COS/2.
2. Set the switches for your application as described in Section 3.2.
3. Replace the cover of the S-COS/2.
4. Connect the serial devices to the terminals on the rear of the S-COS/2.
5. Plug the power cord into the AC wall outlet.
6. Apply power to the connected devices.
The S-COS/2 is now ready for operation.
POWER UP TO
SWITCH TIME MODE
POWER UP
TO PORT A
POWER UP
TO PORT B

SERIAL CODE OPERATED SWITCH S-COS/2
12
4. Operation
4.1 Modes of Operation
The S-COS/2 has three possible modes of operation: MODE 1 (text mode), DISABLED (manual
mode), and MODE 2 (transparent or graphics mode). These modes are selected by the two switches
on the front panel.
MODE 1 (TEXT MODE)
To operate in mode 1, the mode switch must be in the MODE 1 position and the manual switch must
be in the COS position. In this mode, switching a channel port to the master port is done using software
commands. The device connected to the master port sends an arming character to the S-COS/2.
The arming character is selected by SW3 (see Section 4.3 for the possible arming characters).
NOTE: The arming character must be a character that is not used in the text during normal operation
of the S-COS/2. Arming characters are not passed through the
S-COS/2.
When the S-COS/2 receives an arming character, it enters the Switch Time mode. In Switch Time mode,
the S-COS/2 can switch port A or port B to the master port. The master port must send hex code 31H
to connect to port A or hex code 32H to connect to port B.
NOTE: Any signal sent from the master port other than than hex codes 31H or 32H when the unit is in
Switch Time mode will not be passed by the S-COS/2.
When a channel port is connected to the master port, the S-COS/2 enters the channel-selected setting and
the channel port connected to the master port is shown on the corresponding front-panel LED. Circuits
TD, RD, DSR, and DTR are connected between the master port and the appropriate channel port. After
the channel has been selected, all codes (except the arming character) can be sent through the unit.
Only the master port can send an arming character to terminate the channel-selected setting and
bring the S-COS/2 back to the Switch Time mode. Turning the power off and on will also terminate
this mode (the S-COS/2 will power up according to the setting of jumper J2).
NOTE: Only the device connected to the master port can send arming charcters and hex codes 31H and
32H to select the desired channel ports. The mode 1 switching operations cannot be initiated by
the devices connected to ports A and B.
This mode of operation would normally be used when you are certain that no arming characters are
going to be sent to the S-COS/2 except for port selection.
Figure 5. The front panel of the Serial Code Operated Switch S-COS/2
MODE 1
DISABLE
MODE 2 A
AB
COS
B
SWITCH TIME
MODE

SERIAL CODE OPERATED SWITCH S-COS/2
13
DISABLED (MANUAL MODE)
When the mode switch is in the Disabled position, the master port of the S-COS/2 is connected
to the port selected by the manual switch (A or B). All characters will be passed at all times and
code operation is not possible.
MODE 2 (TRANSPARENT OR GRAPHICS)
To operate in mode 2, the mode switch must be in the MODE 2 position and the manual toggle switch
must be in the COS position. DIP switch 1, position 7 must be closed and position 8 must be open.
NOTE: Only the device connected to the master port can control the switching in this mode.
The first character sent from the device connected to the master port must be the arming character
(selected by Switch S3) followed immediately by the port letter (A or B) that is to be connected to the
master port. Once the channel port is switched to the master port, all characters will be passed—
including arming characters. Switching channel ports requires a period of time (selected by Switch S7)
to elapse after transmission has stopped before the S-COS/2 can be set to switch ports. To switch ports
after the timeout period, the master port must send the arming character immediately followed by the
channel port letter.
4.2 Manual Override
The switch in the center of the front panel is for manual override. When this switch is in the COS
position, code operation is possible as per the setting of the mode switch.
Set the manual override switch to position A and set the mode switch to the DISABLE position to have
the master port connected to port A. Set the manual override switch to position B and set the mode
switch to the DISABLE position to have the master port connected to port B. All characters will be
passed through the S-COS/2.
4.3 Switch SW3 Arming Code Settings
EOT is the factory-default arming character.
1 = Closed (ON); 0 = Open (OFF)
ARMING CHARACTER SWITCH POSITIONS
LSB MSB
ASCII CTRL HEX DECIMAL 1 2 3 4 5 6 7 8
NUL @ 00 0 11 1 1 1 1 11
SOH A 01 1 01 1 1 1 1 11
STX B 02 2 10 1 1 1 1 11
ETX C 03 3 00 1 1 1 1 11
EOT D 04 4 11 0 1 1 1 11
ENQ E 05 5 01 0 1 1 1 11
ACK F 06 6 10 0 1 1 1 11
BEL G 07 7 00 0 1 1 1 11
BS H 08 8 11 1 0 1 1 11

SERIAL CODE OPERATED SWITCH S-COS/2
14
ARMING CHARACTER SWITCH POSITIONS
LSB MSB
ASCII CTRL HEX DECIMAL 1 2 3 4 5 6 7 8
HT I 09 9 01 1 0 1 1 11
LF J 0A 10 1 0 1 0 1 1 1 1
VT K 0B 11 0 0 1 0 1 1 1 1
FF 0C 12 1 1 0 0 1 1 1 1
CR M 0D 3 01 0 0 1 1 11
SO N 0E 14 1 0 0 0 1 1 1 1
SI O 0F 15 0 0 0 0 1 1 1 1
DLE P 10 16 1 1 1 1 0 1 1 1
DC1 Q 11 17 0 1 1 1 0 1 1 1
DC2 R 12 18 1 0 1 1 0 1 1 1
DC3 S 13 19 0 0 1 1 0 1 1 1
DC4 T 14 20 1 1 0 1 0 1 1 1
NAK U 15 21 0 1 0 1 0 1 1 1
SYN V 16 22 1 0 0 1 0 1 1 1
ETB W 17 23 0 0 0 1 0 1 1 1
CAN X 18 24 1 1 1 0 0 1 1 1
EM Y 19 25 0 1 1 0 0 1 1 1
SUB Z 1A 26 1 0 1 0 0 1 1 1
ESC [ 1B 27 0 0 1 0 0 1 1 1
FS \ 1C 28 1 1 0 0 0 1 1 1
GS ] 1D 29 0 1 0 0 0 1 1 1
RS ^ 1E 30 1 0 0 0 0 1 1 1
US __ 1F 31 0 0 0 0 0 1 1 1
SPACE 20 32 1 1 1 1 1 0 1 1
!213301111011
"223410111011
#233500111011
$243611011011
%2537O1011011
&263810011011
'273900011011
(284011101011
)294101101011
.2A4210101011

SERIAL CODE OPERATED SWITCH S-COS/2
15
ARMING CHARACTER SWITCH POSITIONS
LSB MSB
ASCII CTRL HEX DECIMAL 1 2 3 4 5 6 7 8
+2B4300101011
,2C4411001011
-2D4501001011
.2E4610001011
/2F4700001011
0304811110011
1314901110011
2325010110011
3335100110011
4345211010011
5355301010011
6365410010011
7375500010011
8385611100011
9395701100011
:3A5810100011
;3B5900100011
<3C6011000011
=3D6101000011
> 3E 2 10 0 0 0 0 11
?3F6300000011
@406411111101
A416501111101
B426610111101
C436700111101
D446811011101
E456901011101
F467010011101
G477100011101
H487211101101
I497301101101
J4A7410101101
K4B7500101101
L 4C 6 11 0 0 1 1 01

SERIAL CODE OPERATED SWITCH S-COS/2
16
ARMING CHARACTER SWITCH POSITIONS
LSB MSB
ASCII CTRL HEX DECIMAL 1 2 3 4 5 6 7 8
M4D7701001101
N4E7810001101
O4F7900001101
P508011110101
Q518101110101
R528210110101
S538300110101
T548411010101
U558501010101
V568610010101
W578700010101
X588811100101
Y598901100101
Z5A9010100101
[ 5B 1 00 1 0 0 1 01
5C 92 1 1 0 0 0 1 0 1
]5D9301000101
5E 94 10 0 0 0 1 01
<- 5F 95 0 0 0 0 0 1 0 1
-609611111001
a 61 7 01 1 1 1 0 01
b629810111001
1639900111001
d 64 100 11 0 1 1 0 01
e 65 101 01 0 1 1 0 01
f 66 102 10 0 1 1 0 01
g 67 103 00 0 1 1 0 01
h 68 104 11 1 0 1 0 01
i 69 105 01 1 0 1 0 01
j 6A 106 10 1 0 1 0 01
k 6B 107 00 1 0 1 0 01
l 6C 108 11 0 0 1 0 01
m 6D 109 01 0 0 1 0 01
n 6E 110 10 0 0 1 0 01

SERIAL CODE OPERATED SWITCH S-COS/2
17
ARMING CHARACTER SWITCH POSITIONS
LSB MSB
ASCII CTRL HEX DECIMAL 1 2 3 4 5 6 7 8
0 6F 111 00 0 0 1 0 01
p 70 112 11 1 1 0 0 01
q 71 113 01 1 1 0 0 01
r 72 114 10 1 1 0 0 01
s 73 115 00 1 1 0 0 01
t741611010001
u 75 117 01 0 1 0 0 01
v 76 118 10 0 1 0 0 01
w 77 119 00 0 1 0 0 01
x 78 120 11 1 0 0 0 01
y 79 121 01 1 0 0 0 01
z 7A 122 10 1 0 0 0 01
7B 123 0 0 1 0 0 0 0 1
-- 7C 124 11 0 0 0 0 01
7D 125 01 0 0 0 0 01
7E 126 1 0 0 0 0 0 0 1
DEL 7F 127 0 0 0 0 0 0 0 1