FEBRUARY 1998
IC456A-R3
IC456A-R4
IC456C-R3
IC456C-R4
RS-232↔RS-422
Interface Converter
232
422
A
T
DSR CTS DA
T
PWR
RR
A
T
DSR CTS DA
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
CUSTOMER
SUPPORT
INFORMATION
RS-232↔RS-422 INTERFACE CONVERTER
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.
2
RS-232↔RS-422 INTERFACE CONVERTER
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.
3
RS-232↔RS-422 INTERFACE CONVERTER
Contents
Chapter
Page
1.Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
3. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3.1 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3.2 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4. Ground Strap and Interface Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4
RS-232↔RS-422 INTERFACE CONVERTER
1. Specifications
64,000 bps, max.
Speed —
Connectors —
Indicators —
RS-232 port: DB25 female; RS-422 port: DB37 female
7 LEDs show status of RS-232 and RS-422 signals and indicate power ON.
RS-232 Port: DSR, CTS, DATA;
RS-422 Port: DSR, CTS, DATA
Controls —
RS-232 port: DTE/DCE DIP shunts;
RS-422 port: DTE/DCE DIP shunts;
DIP switch to enable receiver termination
Environment — Storage Temperature: -4 to +158°F (-20 to +70°C);
Operating Temperature: 32 to 122°F (0 to 50°C)
Power —
Size —
115 VAC Supply: 10%, 100 mA
230 VAC Supply: 10%, 50 mA
Standalone: 2.3"H x 8"W x 11.9"D (5.8 x 20.3 x 30.2 cm);
Rackmount: 1.2"H x 7.5"W x 11.4"D (3.1 x 19.1 x 29 cm)
Weight —
Standalone: 2 lb. (1 kg);
Rackmount: 10 oz. (283.5 g)
5
RS-232↔RS-422 INTERFACE CONVERTER
2. Introduction
The RS-232↔RS-422 Interface Converter provides bi-directional synchronous or asynchronous
conversion of all commonly used RS-232 and RS-422 signals. The unit is designed to operate with one
port configured as Data Terminal Equipment (DTE) and the other port as Data Communications
Equipment (DCE). Operation is not recommended with both ports configured either DCE or both DTE,
when operating in synchronous mode.
The unit has two user-selectable configurations: one for connecting RS-422 modem equipment to RS-232
terminal equipment (DCE to DTE) and one for connecting RS-232 modem equipment to RS-422
terminal equipment (DCE to DTE). Both configurations allow bi-directional data transfer. Typical
applications are shown in Figure 2-1.
Things to consider when operating the converter:
DIP-SHUNT SETTINGS:
RS-232
DTE
RS-422
DCE
INTERFACE
CONVERTER
MODEM
ELIMINATOR
(RS-232)
SYNC
RS-422
COMPUTER
SYNC
RS-232
COMPUTER
DIP-SHUNT SETTINGS:
RS-422
RS-232
DTE
DCE
RS-422
MODEM
INTERFACE
CONVERTER
RS-232
TERMINAL
DIP-SHUNT SETTINGS:
RS-232
DTE
RS-422
DCE
RS-232
MODEM
INTERFACE
CONVERTER
RS-422
TERMINAL
4-WIRE CABLE
DIP-SHUNT
SETTINGS:
6 (R-)
T-
RS-232
DCE
RS-422
DTE
24 (R+)
4 (T-)
T+
R-
22 (T+)
R+
INTERFACE
CONVERTER
PC
INDUSTRIAL
CONTROLLER
Figure 2-1. Various Applications Showing DCE/DTE Settings.
6
RS-232↔RS-422 INTERFACE CONVERTER
1. The Converter does not require special handshaking signals in order to operate.
2. The Converter should always be configured the opposite of the equipment it’s connected to if
straight-through cabling is used. For example, if you are connecting a modem (a DCE device) to the
Converter, configure the Converter’s port connected to the modem as DTE.
3. Some industrial controllers include RTS+, RTS-, CTS+, and CTS-. If necessary, in most cases, these
can be jumpered together.
4. According to EIA specifications, RS-422 signals are A and B, where mark = B>A in voltage and space
+ A>B in voltage. Many manufacturers label their leads as + and -. In most cases, +=B and -=A is the
scheme the Converter uses. However, some manufacturers have reversed this scheme. Consult the
manufacturer of your RS-422 equipment if you have problems.
Models
There are three models of the RS-232↔RS-422 Interface Converter.
• IC456A-R3 — a standalone unit for 115-VAC operation.
• IC456AE-R3 — a standalone unit for 230-VAC operation.
• IC456C-R3 — a printed circuit card for rack-mounted units.
The same RS-232↔RS-422 printed circuit card is used for both 115- and 230-VAC applications. An
Interface Converter Rack (RM060) is available through your sales representative. This is a 19-inch rack
capable of holding up to eight printed-circuit cards. The rack has its own power supply which is switch
selectable between 115- and 230-VAC operation.
If you ordered the IC456A-R4 or IC456C-R4, you should have received cables with your RS-232↔RS-422
Interface Converter.
7
RS-232↔RS-422 INTERFACE CONVERTER
3. Installation
To connect the Converter to your devices, follow these steps:
1. Attach the cable from the RS-422 device to the 37-pin female receptacle on the rear panel of the
Converter.
2. Attach the cable from the RS-232 device to the 25-pin female receptacle on the rear panel of the
Converter.
3. Plug the 4-pin power cord into the receptacle on the rear panel of the case. However, don’t plug the
power module into an AC outlet at this time. You can power up only after you have configured the
Converter’s DTE/DCE DIP shunts (Section 3.1).
3.1 Configuration
The Converter’s RS-232 and RS-422 ports must each be set for DCE or DTE operation. Configuration is
accomplished through DIP shunts located inside the unit on the printed circuit board (see Figures 3-1
and 3-2). One configuration is for connecting RS-422 DCE to RS-232 DTE. The second configuration is
for connecting RS-232 DCE to RS-422 DTE. Refer to Table 3-1 for the DTE/DCE settings appropriate to
your application.
Table 3-1. DTE/DCE DIP Shunt Settings.
RS-422 Port
put a DIP shunt
RS-232 Port
to appear
as
to appear
as
put a DIP shunt
in
in
DTE
XW1A
XW2A
XW3A
DTE
XW4A
XW5A
DCE
XW1B
XW2B
XW3B
DCE
XW4B
XW5B
8
RS-232↔RS-422 INTERFACE CONVERTER
RACK POWER
CONNECTOR
AC POWER
CONNECTOR
RS-422
CONNECTOR
RS-232
CONNECTOR
XW1A XW2A
XW3A XW4A XW4B XW5A
DIP SHUNTS
XW5B
XW1B XW2B XW3B
DIP SHUNTS
S1
CR8 CR5 CR6
CR10
CR9 CR4 CR7
DSR CTS DATA
DSR CTS DATA
POWER
RS-422
INDICATORS
RS-232
INDICATORS
Figure 3-1. Board Layout Showing Component Locations.
(Dashed Lines show DTE/DCE DIP Shunt Locations.)
9
RS-232↔RS-422 INTERFACE CONVERTER
RS-422 INTERFACE
SET TO DCE
DSR
CR8 RS-422 TO RS-232 DTR/DSR
P1
DTE
DTE
DCE
DCE
DCE
CTS
CR5 RS-422 TO RS-232 RTS/CTS
CR6 RS-422 TO RS-232 DATA
XW1A
XW2A
XW1B
XW2B
XW3B
DATA
DTE
DTE
DCE
DTE
DB37 PIN
FEMALE
J1
XW3A
XW4A
XW4B
XW5A
POWER
DSR
CR10
CR9 RS-232 TO RS-422 DTR/DSR
CTS
CR4 RS-232 TO RS-422 RTS/CTS
CR7 RS-232 TO RS-422 DATA
OFF <-> ON
S1
DB25 PIN
FEMALE
DCE
J2
DATA
XW5B
RS-232 INTERFACE
SET TO DTE
Figure 3-2. Sample DIP-Shunt Setting.
Figure 3-2 shows the DIP-shunt settings used for an application like the one illustrated in
Figure 3-3a.
NOTE
The filled-in rectangles in Figure 3-2 indicate the jumpers that contain a DIP-shunt.
CAUTION
Never set both ports the same: the clocks will not operate correctly. If two DTEs are
connected through the Converter, a modem eliminator is required in order to avoid
setting both ports the same. If two DCEs are connected together, a cross-over cable is
required.
10
RS-232↔RS-422 INTERFACE CONVERTER
Figures 3-3a and 3-3b show some typical synchronous applications.
DIP SHUNT SETTINGS
RS-232
DTE
RS-422
DCE
INTERFACE
CONVERTER
RS-232 MODEM
OR MODEM
ELIMINATOR
RS-232
TERMINAL
DIP SHUNT SETTINGS
RS-232
DCE
RS-422
DTE
INTERFACE
CONVERTER
RS-232 MODEM
OR MODEM
ELIMINATOR
PC
Figure 3-3. Synchronous Applications.
Applications involving asynchronous devices are also possible. Figure 3-4 illustrates a popular
asynchronous setup, while Figure 3-5 shows the cabling involved.
DIP-SHUNT
SETTINGS:
22 (T+)
4 (T-)
R+
R-
DCE
DTE
24 (R+)
6 (R-)
T+
DB25
STRAIGHT
CABLE
RS-232/RS-422
INTERFACE
CONVERTER
T-
RS-422
DEVICE
PC OR OTHER
DTE DEVICE
19 (FRAME
GND)
GND
(GROUND
OPTIONAL)
Figure 3-4. RS-422 Asynchronous Application.
11
RS-232↔RS-422 INTERFACE CONVERTER
THE RECEIVER TERMINATION SWITCH
This switch is marked S1 on the printed circuit-board diagram in Figures 3-1 and 3-2. This switch serves
to terminate the receiver with pull-up and pull-down resistors in order to designate the receiver state and
enable the Converter’s anti-streaming function. Setting the switch to the ON position closes the switch,
setting the switch to OFF opens the switch.
3.2 LEDs
The RS-232↔RS-422 Interface Converter is equipped with seven LEDs located on the front panel that
indicate the status of INPUT signals.
The three LEDs on the right side of the front panel show conditions on the RS-232 interface: DSR
(Data Set Ready), CTS (Clear To Send), and Data.
The three LEDs on the left side of the panel show the same conditions on the RS-422 interface: DSR
(Data Set Ready), CTS (Clear To Send), and Data.
The LED labeled PWR, located in the center of the front panel, indicates when power is applied to
the unit.
Figures 3-5 and 3-6 illustrate signal flow in both the DTE and DCE configurations.
NOTE
Some LEDs may be lit when no input signal is present. This is not a malfunction, but a
floating state condition at the input that causes the output of that driver to indicate a
positive voltage condition.
12
RS-232↔RS-422 INTERFACE CONVERTER
RS-232 RS-422 Signal Flow Diagram
↔
(Arrows indicate the direction of signal flow.)
RS-232
(Port is DTE)
RS-422
(Port is DCE)
SW1 A
CR6
(RS-422 DATA LED)
(RS-232 DATA LED)
4
Send Data A (-)
TD
2
3
22 Send Data B (+)
Receive Data A (-)
24 Receive Data B (+)
Request to Send A (-)
25 Request to Send B (+)
Clear to Send A (-)
SW1 B
CR7
6
RD
CR5
CR4
CR9
(RS-422 CTS LED)
(RS-232 CTS LED)
(RS-232 DSR LED)
7
4
5
6
RTS
CTS
9
27 Clear to Send B (+)
11 Data Mode A (-)
29 Data Mode B (+)
DSR
CD
13 Receiver Ready A (-)
31 Receiver Ready B (+)
8
5
Send Timing A (-)
TXC 15
RXC 17
23 Send Timing B (+)
8
Receive Timing A (-)
26 Receive Timing B (+)
12 Terminal Ready A (-)
CR8
(RS-422 DSR LED)
20
DTR
Terminal Ready B (+)
30
17 Terminal Timing A (-)
35
ETXC 24
Terminal Timing B (+)
Chassis
GND
Chassis or Frame
1
7
1
GND
GND
Optional Jumper
*
19 Signal GND
20 Receive Common
Signal
GND
37
Transmit Common
* Note: The optional jumper is removed (factory default
Figure 3-5. Signal Flow Diagram A.
13
RS-232↔RS-422 INTERFACE CONVERTER
RS-232 RS-422 Signal Flow Diagram
↔
(Arrows indicate the direction of signal flow.)
RS-232
(Port is DCE)
RS-422
(Port is DTE)
CR7
(RS-232 DATA LED)
(RS-422 DATA LED)
4
Send Data A (-)
TD
2
3
22 Send Data B (+)
Receive Data A (-)
24 Receive Data B (+)
Request to Send A (-)
25 Request to Send B (+)
Clear to Send A (-)
SW1 B
SW1 A
CR6
6
RD
CR4
CR5
(RS-232 CTS LED)
(RS-422 CTS LED)
7
4
5
6
RTS
CTS
9
27 Clear to Send B (+)
CR8
(RS-422 DSR LED)
11 Data Mode A (-)
29 Data Mode B (+)
DSR
CD
13 Receiver Ready A (-)
31 Receiver Ready B (+)
8
5
Send Timing A (-)
TXC 15
RXC 17
23 Send Timing B (+)
8
Receive Timing A (-)
26 Receive Timing B (+)
12 Terminal Ready A (-)
CR9
(RS-232 DSR LED)
20
DTR
Terminal Ready B (+)
30
17 Terminal Timing A (-)
35
ETXC 24
Terminal Timing B (+)
Chassis
GND
Chassis or Frame
1
1
7
GND
GND
Optional Jumper
*
19 Signal GND
20 Receive Common
Signal
GND
37
Transmit Common
* Note: The optional jumper is removed (factory default
Figure 3-6. Signal Flow Diagram B.
14
RS-232↔RS-422 INTERFACE CONVERTER
4. Ground Strap and Interface Pinouts
Signal grounds (Pins 19, 20, and 37 on the RS-422 interface and Pin 7 on the RS-232 interface) are
connected together, but not connected to chassis ground (Pin 1). However, for applications requiring all
grounds to be at a common reference point, these pins can be connected to chassis ground by installing
a jumper strap across W6 located at the rear of the printed-circuit board between J1 and P1 (refer to
Figures 4-1 and 4-2).
PROTECTIVE GROUND
1
2
14
SECONDARY TRANSMITTED DATA
TRANSMITTED DATA
DCE TRANSMITTER SIGNAL ELEMENT TIMING 15
3 RECEIVED DATA
SECONDARY RECEIVED DATA
16
17
18
19
20
21
22
23
24
25
4 REQUEST TO SEND
RECEIVER SIGNAL ELEMENT TIMING
5 CLEAR TO SEND
DATA SET READY
6
7
8
SECONDARY REQUEST TO SEND
DATA TERMINAL READY
SIGNAL GROUND/COMMON RETURN
RECEIVED LINE SIGNAL DETECTOR
+ VOLTAGE
SIGNAL QUALITY DETECTOR
9
RING INDICATOR
-VOLTAGE
10
11
12
13
DATA SIGNAL RATE SELECTOR
DTE TRANSMITTER SIGNAL ELEMENT TIMING
SECONDARY RECEIVED LINE SIGNAL
DETECTOR
SECONDARY CLEAR TO SEND
Figure 4-1. The RS-232 Interface.
1
2
3
4
5
6
7
8
9
SHIELD
RECEIVE COMMON
20
21
22
23
24
25
26
27
28
29
30
31
SIGNALING RATE INDICATOR
(+B) SEND DATA
(+B) SEND TIMING
SEND DATA (-A)
SEND TIMING (-A)
RECEIVE DATA (-A)
REQUEST TO SEND (-A)
RECEIVE TIMING (-A)
CLEAR TO SEND (-A)
(+B) RECEIVE DATA
(+B) REQUEST TO SEND
(+B) RECEIVE TIMING
(+B) CLEAR TO SEND
TERMINAL IN SERVICE
(+B) DATA MODE
10 LOCAL LOOPBACK
DATA MODE (-A)
11
12
13
14
15
16
17
18
19
(+B) TERMINAL READY
(+B) RECEIVER READY
TERMINAL READY (-A)
RECEIVER READY (-A)
REMOTE LOOPBACK
INCOMING CALL
SELECT FREQUENCY
TERMINAL TIMING (-A)
TEST MODE
SELECT STANDBY 32
SIGNAL QUALITY 33
NEW SIGNAL
(+B) TERMINAL TIMING
STANDBY/INDICATOR
SEND COMMON
34
35
36
37
SIGNAL GROUND
Figure 4-2. The RS-422 Interface.
15
© Copyright 1998. Black Box Corporation. All rights reserved.
1000 Park Drive Lawrence, PA 15055-1018 724-746-5500
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•
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Fax 724-746-0746
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