Terminal Server
Cable Guide
Including All PortServer and Digi One Products
90000253_A
Digi International Inc. 2001. All Rights Reserved
The Digi logo is a trademark of Digi International Inc. All other brand and product names are the trademarks of their respective holders.
Information in this document is subject to change without notice and does not represent a commitment on the part of Digi International.
Digi provides this document “as is,” without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of fitness or merchantability for a particular purpose. Digi may make improvements and/or changes in this manual or in the product(s) and/or the program(s) described in this manual at any time.
This product could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein; these changes may be incorporated in new editions of the publication.
90000253_A
Contents
Chapter 1
EIA-232 Asynchronous Interface
General EIA-232 Cable Information.................................................................... 1-2
Physical Cable Characteristics ....................................................................... 1-2
Grounding Requirements ............................................................................... 1-2
Environmental Requirements ......................................................................... 1-2
Data Rate Information .................................................................................... 1-2
Data Rate vs. Cable Length ............................................................................ 1-2
Transmission Errors ....................................................................................... 1-3
Chapter 2
EIA-232: DB 25 to DB25
Digi DB-25 Connector Pin Assignments ............................................................. 2-2
DB-25 Software Handshaking (XON/XOFF) Cable ........................................... 2-2
DB-25 4-Wire Hardware Handshaking (DTR) Cable.......................................... 2-3
DB-25 Hardware Handshaking (RTS/CTS) Cable .............................................. 2-3
DB-25 Fully-Wired Terminal/Printer Cable ........................................................ 2-4
DB-25 Modem Cable ........................................................................................... 2-4
Chapter 3
EIA-232: RJ to DB-25
Digi RJ-45 Connector Pin Assignments .............................................................. 3-2
RJ Connector Types ............................................................................................. 3-3
Digi RJ-45 to DB-25/DB-9 Cable Adapters ........................................................ 3-4
RJ-11 Software Handshaking (XON/XOFF) Cable............................................. 3-5
RJ-45 8-Pin Plug Hardware Handshaking (DTR) Cable ..................................... 3-6
RJ-45 8-Pin Plug Hardware Handshaking (RTS/CTS) Cable ............................. 3-7
RJ-45 8-Wire ALTPIN Terminal/Printer Cable................................................... 3-8
RJ-45 Fully-Wired Terminal/Printer Cable ......................................................... 3-9
RJ-45 8-Pin to Modem (ALTPIN option).......................................................... 3-10
RJ-45 10-Pin Plug to DB-25 Modem Cable ...................................................... 3-11
i
ii
Chapter 4
EIA-422 Asynchronous Interface
General EIA-422 Cable Information.................................................................... 4-2
Physical Cable Characteristics ....................................................................... 4-2
EIA-422 Interface Signaling .......................................................................... 4-2
EIA-422 Grounding Requirements ................................................................ 4-2
Digi EIA-422 Connector Wiring.......................................................................... 4-3
EIA-422 Software Handshaking (XON/XOFF) Cable ........................................ 4-4
EIA-422 Hardware Handshaking (Ready/Busy) Cable ....................................... 4-5
EIA-422 DTE to DCE (Modem) Cable ............................................................... 4-6
Chapter 1
EIA-232 Asynchronous Interface
EIA-232 Asynchronous Interface
1-1
General EIA-232 Cable Information
Use this information to determine the proper EIA-232 cable requirements for your application.
Physical Cable Characteristics
EIA-232 serial interface cables should be shielded, low capacitance cables, designed specifically for serial data transmission.
Grounding Requirements
EIA-232 interface cables should have the shield grounded at both ends of the cable. Digi recommends Chassis Ground, available on the shell of Digi's DB-25 connectors, and pin 4 of a 10pin RJ-45 connector.
Environmental Requirements
While good shielding provides reasonable protection against "noise" (electromagnetic interference, or EMI), cables should still be routed away from noise sources wherever possible. Avoid laying cables in close proximity to transformers, generators, motors, fluorescent lights, etc.
Data Rate Information
The maximum data rate that can be used for EIA-232 connections is primarily determined by the quality and length of the interconnecting cable. The quality of the cable (for transmission purposes) is generally determined by the capacitance per foot rating of the cable.
The following table gives the recommended maximum cable length for a given data rate. Longer cables may be implemented at your discretion. Note that not all Digi products support all of the data rates listed below.
Data Rate vs. Cable Length
Data Rate (bps) Maximum Cable Length
57,600 or less
115,200
230,400
460,800
100 feet
80 feet
40 feet
20 feet
921,600 10 feet
Notes:
The maximum length is the amount of cable that is connected to a Digi supplied interconnect device, such as Quad or Octa cables and boxes.
The maximum length is based on a cable rated at:
12.3 pF/foot, conductor to conductor
22.4 pF/foot conductor to shield
In situations where low-capacitance cable is unavailable, or very long cable runs are required,
"short-haul" modems can be used to increase the effective range of the EIA-232 interface. Shorthaul modems are similar to standard modems, except that they are connected directly to each other via a cable instead of going through a telephone circuit.
Note: Use only externally-powered short-haul modems with Digi products.
1-2
General EIA-232 Cable Information
Transmission Errors
If transmission errors occur, follow this procedure to determine the cause of the problem:
1. Reduce the baud rate.
2. Reduce the cable length.
3. Use a cable with a lower capacitance per foot rating.
EIA-232 Asynchronous Interface
1-3
1-4
General EIA-232 Cable Information
Chapter 2
EIA-232: DB 25 to DB25
EIA-232: DB 25 to DB25
2-1
Digi DB-25 Connector Pin Assignments
Signal
GND
TxD
RxD
RTS
CTS
DSR
SG
DCD
DTR
RI
Description
Chassis Ground
Transmitted Data
Received Data
Request to Send
Clear to Send
Data Set Ready
Signal Ground
Data Carrier Detect
Data Terminal Ready
Ring Indicator
DTE Use
N/A
Output
Input
Output
Input
Input reference
Input
Output
Input
Pin #
8
20
22
6
7
4
5
Shell
2
3
DB-25 Software Handshaking (XON/XOFF) Cable
The following three-wire cable is often sufficient for a terminal, printer, or other DTE device configured for software flow control.
Simple Terminal/Printer Cable
DB-25 Male
(Peripheral)
DB-25 Female
(Digi End)
Signal
TxD
RxD
SG
GND
2
3
7 shell
Pin
connected to connected to connected to connected to (via shield)
Pin
3
2
7 shell
Signal
RxD
TxD
SG
GND
This cable is a three-wire null modem cable. Transmitted Data on one end of the cable is connected to Received Data at the other end, and vice versa. The male DB-25 end can be plugged directly into most serial terminals and printers without any adapters. The female DB-25 end plugs directly into any Digi DB-25 serial port."
2-2
Digi DB-25 Connector Pin Assignments
DB-25 4-Wire Hardware Handshaking (DTR) Cable
The following four-wire cable is often sufficient for an older terminal, printer, or other DTE device configured for DTR (hardware) flow control. However, some terminals and printers may use a signal other than DTR for flow control. In addition, some terminals and printers may have other cable requirements. Consult your terminal or printer manual for this information. For more universal compatibility, use a full-wired DB-25 terminal/printer cable.
Terminal/Printer Cable with DTR Handshaking
DB-25 Female
(Digi End)
DB-25 Male
(Peripheral)
Signal
TxD
RxD
CTS
SG
GND
Pin
5
7
2
3
Shell jumpered connected to connected to connected to connected to connected (via shield) to
4+5
Pin
3
2
20
7
Shell
RTS+CTS
Signal
RxD
TxD
DTR
SG
GND
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
DB-25 Hardware Handshaking (RTS/CTS) Cable
The following cable is often sufficient for a terminal, printer, or other DTE device configured for
RTS/CTS (hardware) flow control. However, some terminals and printers may have other cable requirements. Consult your terminal or printer manual for this information. For more universal compatibility, use a fully-wired DB-25 terminal/printer cable.
Terminal/Printer Cable with RTS/CTS Handshaking
DB-25 Female
(Digi End)
Signal
TxD
RxD
2
Pin
3 connected to connected to
3
Pin
2
DB-25 Male
(Peripheral)
Signal
RxD
TxD
CTS
SG
5
7 connected to connected to
4 RTS
20 DTR
7 SG
GND Shell connected (via shield) to Shell GND
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
EIA-232: DB 25 to DB25
2-3
DB-25 Fully-Wired Terminal/Printer Cable
The following cable wiring supports most serial terminals or printers with either software or hardware handshaking. This cable is valid with any Digi DB-25 serial port.
Terminal/Printer Cable for Software (XON/XOFF) or Hardware (DTR) Handshaking
DB-25
(Digi End)
DB-25 Male
(Terminal/Printer)
Signal
RTS
GND
TxD
RxD
SG
CTS
DTR
DCD+DSR
3
7
5
20
8+6
Pin
4
Shell
2 connected to connected to connected to connected to connected to connected to connected to connected to
2
7
20
8+6
4
Pin
5
Shell
3
Signal
CTS
GND
RxD
TxD
SG
DTR
DCD+DSR
RTS
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
DB-25 Modem Cable
To connect a DB-25 equipped asynchronous adapter to a modem, use a standard "straight-through" cable. A straight-through cable has a DB-25 female connector at the Digi end, and a DB-25 male connector at the modem end. All 25 pins are connected, 1 to 1, 2 to 2, 3 to 3, etc. Use shielded cable, and connect pin 1 of each connector to the cable shield.
2-4
DB-25 Fully-Wired Terminal/Printer Cable
Chapter 3
EIA-232: RJ to DB-25
EIA-232: RJ to DB-25
3-1
Digi RJ-45 Connector Pin Assignments
10-pin RJ-45 plugs may be difficult to obtain in the retail market; therefore, most Digi device driver software incorporates an optional feature called ALTPIN, which swaps the logical functions of DSR
(Data Set Ready) with DCD (Data Carrier Detect).
When ALTPIN is enabled, DCD becomes available on pin 1 of an 8-pin RJ-45 connector (equivalent to pin 2 of a 10-pin connector).
Signal Description
TxD
RxD
SG
CTS
RI
DSR (DCD*)
RTS
GND
DTR
DCD (DSR*)
*When ALTPIN is in effect.
Ring Indicator
Data Set Ready (Data Carrier Detect*)
Request to Send
Chassis Ground
Transmitted Data
Received Data
Signal Ground
Clear to Send
Data Terminal Ready
Data Carrier Detect (Data Set Ready*)
DTE Use
Input
Input
Output
N/A
Output
Input reference
Input
Output
Input
Pin #
7
8
5
6
3
4
1
2
9
10
3-2
Digi RJ-45 Connector Pin Assignments
RJ Connector Types
The following table shows the relationship of various RJ plugs to the Digi RJ-45 10-pin jack. The
Digi 10-pin jack can accept any of the listed plug types. The wiring of each plug type corresponds to support of specific capabilities such as software handshaking, hardware handshaking, and the Digi
ALTPIN feature.
RJ-45
8-Pin
Plug
RJ-11
6-Pin
Plug
RJ-11
4-Pin
Plug
7
8
9
10
5
6
3
4
1
2
Digi
10-Pin
Jack
Signal Name
TxD
RxD
SG
CTS
RI
DSR (DCD*)
RTS
GND
DTR
DCD (DSR*)
*When ALTPIN is in effect.
9
10
7
8
5
6
3
4
1
2
RJ-45
10-Pin
Plug
6
7
4
5
8
1
2
3
3
4
1
2
5
6
1
2
3
4
EIA-232: RJ to DB-25
3-3
Digi RJ-45 to DB-25/DB-9 Cable Adapters
RJ-45 to DB-25/DB-9 cable adapters can be purchased from Digi. These adapters consist of a 10-pin
RJ-45 plug connected via a two- or four-foot cable to a DB-25 or DB-9 connector. The adapters are fully-wired and provide modem control.
Part numbers for RJ-45 to DB-25 Cable Adapters:
Cable RJ45 to DB25M ( Male) DTE 24"
Cable RJ45 to DB25F (Female) DTE 24"
Cable RJ45 to DB25M ( Male) DTE 48"
Cable RJ45 to DB25M ( Male) DCE 48"
Cable RJ45 to DB25F (Female) DTE 48"
Part numbers for RJ-45 to DB-9 Cable Adapters:
76000129
76000198
76000195
76000238
76000199
Cable RJ45 to DB9M ( Male) DTE 24"
Cable RJ45 to DB9F (Female) DTE 24"
Cable RJ45 to DB9M ( Male) DTE 48"
Cable RJ45 to DB9M ( Male) DCE 48"
Cable RJ45 to DB9F (Female) DTE 48"
76000239
76000200
76000240
76000264
76000201
3-4
Digi RJ-45 to DB-25/DB-9 Cable Adapters
RJ-11 Software Handshaking (XON/XOFF) Cable
The following 3-wire cable is often sufficient for a terminal, printer or other DTE device configured for software flow control.
Simple Software Handshaking Terminal/Printer Cable (RJ-11)
RJ-11 (Digi End)
Pin Signal
TxD
RxD
2
3
SG
GND
4
1 connected to connected to connected to connected (via shield) to
3
2
DB-25 Male (Peripheral)
Pin Signal
RxD
TxD
7
1 (or shell)
SG
GND
This cable is a 3-wire null modem cable. Transmitted Data on one end of the cable is connected to
Received Data at the other end, and vice versa.
The RJ-11 plug fits into the center of the RJ-45 jack. The male DB-25 end can be plugged directly into most serial terminals and printers without any adapters.
An RJ-45 8-pin connector uses the same wiring with the center pins only-pins 3, 4, 5, and 6. See the section titled RJ Connector Types for a comparison of various RJ connector types that work with the
Digi 10-pin RJ-45 jack.
EIA-232: RJ to DB-25
3-5
RJ-45 8-Pin Plug Hardware Handshaking (DTR) Cable
Using an 8-pin plug, the following cable wiring is often sufficient for a terminal, printer, or other
DTE device configured for DTR (hardware) flow control. However, some terminals and printers may use a signal other than DTR for flow control. In addition, some terminals and printers may have other cable requirements. Consult your terminal or printer manual for this information. For more universal compatibility, use the RJ-45 10-wire terminal/printer cable or a Digi RJ-45 to DB-25 adapter.
Terminal/Printer Cable with DTR Handshaking
RJ-45 (Digi End)
Pin Signal
TxD
RxD
CTS
SG
GND
4
5
7
6
3 jumpered connected to connected to connected to connected to connected (via shield) to
4+5
DB-25 Male (Peripheral)
Pin
3
2
20
7
1 (or shell)
RTS+CTS
Signal
RxD
TxD
DTR
SG
GND
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
3-6
RJ-45 8-Pin Plug Hardware Handshaking (DTR) Cable
RJ-45 8-Pin Plug Hardware Handshaking (RTS/CTS) Cable
Using an 8-pin plug, the following cable wiring is often sufficient for a terminal, printer, or other
DTE device configured for RTS/CTS (hardware) flow control. However, some terminals and printers may have other cable requirements. Consult your terminal or printer manual for this information. For more universal compatibility, use theRJ-45 10-wire terminal/printer cable or a Digi
RJ-45 to DB-25 adapter.
Terminal/Printer Cable with DTR Handshaking
RJ-45 (Digi End)
Signal Pin
GND
TxD
RxD
SG
CTS
3
4
5
6
7 connected (via shield) to connected to connected to connected to connected to
DB-25 Male (Peripheral)
Pin
20
5
1 (or shell)
7
4
3
2
8
Signal
DTR
CTS
GND
RxD
TxD
SG
RTS
DCD
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
EIA-232: RJ to DB-25
3-7
RJ-45 8-Wire ALTPIN Terminal/Printer Cable
Using an 8-pin RJ-45 plug, the following cable wiring supports most serial terminals or printers with either software or hardware handshaking using the Digi ALTPIN option.
Most terminals and printers use Request to Send/Clear to Send (RTS/CTS) for hardware handshaking. The cable shown supports this method.
ALTPIN Terminal/Printer Cable for Software (XON/XOFF) or Hardware (RTS/CTS) Handshaking
RJ-45 8-pin
(Digi End)
DB-25 Male
(Terminal/Printer)
Signal
DCD*
RTS
GND
TxD
RxD
SG
5
6
3
4
1
Pin
2 connected to connected to connected (via shield) to connected to connected to connected to
2
7
Pin
20
5
Shell
3
Signal
DTR
CTS
GND
RxD
TxD
SG
CTS
DTR
7
8 connected to connected to
4
6+8
RTS
DSR+
DCD
* ALTPIN must be turned on for pin 1 to be DCD. When ALTPIN is enabled, DCD becomes available on pin 1 of an 8-pin RJ-45 connector (equivalent to pin 2 of a 10-pin connector).
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
3-8
RJ-45 8-Wire ALTPIN Terminal/Printer Cable
RJ-45 Fully-Wired Terminal/Printer Cable
Using a 10-pin RJ-45 plug, the following cable wiring supports most serial terminals or printers with either software or hardware handshaking. This cable is valid with any Digi RJ-45 serial port.
Most terminals and printers use Request to Send/Clear to Send (RTS/CTS) for hardware handshaking. The cable shown supports this method.
Terminal/Printer Cable for Software (XON/XOFF) or Hardware (RTS/CTS) Handshaking
RJ-45 10-pin
(Digi End)
Signal Pin
DSR+DCD* 2+10
RTS
GND
TxD
RxD
SG
CTS
5
6
3
4
7
8 connected to connected to connected (via shield) to connected to connected to connected to connected to
DB-25 Male
(Terminal/Printer)
7
4
3
2
Pin
20
5
Shell
RxD
TxD
SG
RTS
Signal
DTR
CTS
GND
DTR 9 connected to 6+8 DSR+DCD
* ALTPIN must be turned off for DCD to be on pin 10.
Important: Some terminal or printer manufacturers may use different methods of flow control.
Consult your documentation for specific wiring requirements.
EIA-232: RJ to DB-25
3-9
RJ-45 8-Pin to Modem (ALTPIN option)
The following table shows how to build an 8-wire modem cable using an 8-pin RJ-45 plug. This cable supports the Digi ALTPIN option when plugged into a Digi RJ-45 serial port.
8-Wire Modem Cable Supporting ALTPIN Option
DB-25 Male
(Modem End)
RJ-45
(Digi End)
Signal Pin
DCD 1
RTS
GND
RxD
TxD
SG
CTS
DTR
6
7
8
4
5
2
3 connected to connected to connected (via shield) to connected to connected to connected to connected to connected to
7
5
3
2
20
Pin
8
4
1 (or shell)
RxD
TxD
SG
CTS
DTR
Signal
DCD
RTS
GND
When ALTPIN is enabled, DCD becomes available on pin 1 of an 8-pin RJ-45 connector (equivalent to pin 2 of a 10-pin connector).
Note: ALTPIN is not supported for the PortServer product under Windows NT. Use a full 10-wire modem cable in this case.
3-10
RJ-45 8-Pin to Modem (ALTPIN option)
RJ-45 10-Pin Plug to DB-25 Modem Cable
The simplest way to connect a modem to a Digi RJ-45 jack is to use a Digi RJ-45 to DB-25 Cable
Adapter. The following table shows how to apply the adapter wiring scheme to custom modem cables.
RJ-45 to DB-25 Modem Cable (10 Wire)
DB-25 Male
(Modem End)
SG
CTS
DTR
DCD
RTS
GND
TxD
RxD
RJ-45
(Digi End)
Signal
RI
DSR
1
2
Pin
7
8
9
10
5
6
3
4 connected to connected to connected to connected (via shield) to connected to connected to connected to connected to connected to connected to
7
5
2
3
Pin
22
6
4
1 (or shell)
20
8
SG
CTS
DTR
DCD
Signal
RI
DSR
RTS
GND
TxD
RxD
EIA-232: RJ to DB-25
3-11
3-12
RJ-45 10-Pin Plug to DB-25 Modem Cable
Chapter 4
EIA-422 Asynchronous Interface
EIA-422 Asynchronous Interface
4-1
General EIA-422 Cable Information
This section applies to Digi products equipped with EIA-422 asynchronous interfaces.
Physical Cable Characteristics
EIA-422 interface cables should be shielded twisted-pair cables. Each signal requires two leads (one twisted pair of wires) to complete a balanced voltage digital circuit. The shield should be connected to the Chassis Ground of the devices at both ends of the interface cable.
EIA-422 Interface Signaling
The EIA-422 interface provides four signals: Transmitted Data (TxD), Received Data (RxD),
Request To Send (RTS) and Clear To Send (CTS). The functions of these signals are identical to their EIA-232 counterparts.
EIA-422 Grounding Requirements
EIA-422 interface cables must provide a ground path between the devices to be connected. This ensures the integrity of data transfers and control signals. This should be connected to the Chassis
Ground of each device. Digi recommends using the cable shield for this purpose.
4-2
General EIA-422 Cable Information
Digi EIA-422 Connector Wiring
A terminal, a serial printer, or a serial port for another computer usually functions as a DTE device.
The Digi adapter is also a DTE device. To connect a DTE device to another DTE device a null modem cable or adapter must be used.
Two wires (one twisted pair) are required for each signal, a positive lead ("+"), and a negative lead
("-"). The "+" leads at one end of the cable must be connected to the "+" leads at the other end, and the "-" leads at one end must be connected to the "-" leads at the other end.
Incorrect wiring could result in damage to the connected devices. The following table shows the pin configurations for the EIA-422 versions of Digi DB-9 and DB-25 connectors.
Signal
TxD+
TxD-
RxD+
RxD-
RTS+
RTS-
CTS+
CTS-
GND
Description
Transmitted Data (+)
Transmitted Data (-)
Received Data (+)
Received Data (-)
Request To Send (+)
Request To Send (-)
Clear To Send (+)
Clear To Send (-)
Chassis Ground
DB-9 Pin
3
4
7
2
8
9
6
5
Shell
DB-25 Pin
16
4
19
5
2
14
3
13
Shell
EIA-422 Asynchronous Interface
4-3
EIA-422 Software Handshaking (XON/XOFF) Cable
Use the chart below as a guide for EIA-422 wiring. Pin numbers have been omitted because they vary from product to product. For Digi pin numbers, see the section titled Digi EIA-422 Connector
Wiring. For peripheral device pin numbers, see the documentation for your peripheral device.
RxD
DTE (Digi End)
Signal
TxD
-
+
-
Lead
+
GND
RTS
Jumpered, connect:
RTS(+) to CTS(+);
RTS(-) to CTS(-)
CTS
Connected to
Connected to
Connected to
Connected to
Connected to
-
+
-
Lead
+
DTE (Peripheral)
Signal
RxD
TxD
GND
Jumpered, connect:
RTS(+) to CTS(+);
RTS(-) to CTS(-)
RTS
CTS
4-4
EIA-422 Software Handshaking (XON/XOFF) Cable
EIA-422 Hardware Handshaking (Ready/Busy) Cable
Use the following table as a guide for EIA-422 wiring. Pin numbers have been omitted because they vary from product to product. For Digi pin numbers, see the section titled Digi EIA-422 Connector
Wiring. For peripheral device pin numbers, see the documentation for your peripheral device.
DTE (Digi End)
Signal
TxD
-
Lead
+
RxD
RTS
CTS
-
+
-
+
-
+
GND
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
-
+
-
+
-
+
DTE (Peripheral)
-
Lead
+
Signal
RxD
TxD
CTS
RTS
GND
EIA-422 Asynchronous Interface
4-5
EIA-422 DTE to DCE (Modem) Cable
Use the chart below as a guide for EIA-422 modem wiring. Pin numbers have been omitted because they vary from product to product. For Digi pin numbers, see the section titled Digi EIA-422
Connector Wiring. For modem pin numbers, see your modem's documentation.
DTE (Digi End)
Signal Lead
TxD +
RxD
RTS
CTS
-
-
+
-
+
-
+
GND
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
Connected to
-
-
+
-
+
-
+
DCE (Modem)
Lead Signal
+ TxD
RxD
RTS
CTS
GND
4-6
EIA-422 DTE to DCE (Modem) Cable
