Model 8381 - RS-422 Opto Isolator DIN Rail Mounted
Reference Manual


Table of Contents

1.0 Description
2.0 Operating Mode
3.0 Connection
4.0 Parameter Selection
5.0 Specifications
6.0 Help
Warranty



1.0 Description

The Model 8381 RS-422 Opto Isolator, provides several benefits when applications call for connecting RS-422 interfaced peripheral equipment. These are regenerating/extending cable distance of RS-422 networks and opto isolation between ports.

Packaged in a sturdy, compact, plastic housing these DIN Rail mountable products easily "snap-on" to industry standard DIN rails. Complete optical isolation between both RS-422 sides is guaranteed thanks to the use of opto couplers.

1-1 RS-422 4 Wire Link Extension

The Model 8381allows for the extension of RS-422 links to a maximum limit of 3,000 feet/1 Km at a data rate of 115.2 KBPS.


1-2 RS-422 (4 wire) Interface

The RS-422 standard, established by the EIA (Electrical Industries Association) in the USA, concerns the electrical characteristics of a digital signal transmission system, full duplex, over a four wire bus, two twisted pairs. The RS-422 interface is very popular in industrial environments due to its common mode noise rejection and its high speed.

NOTE : The choice of cables for RS-422 operation is important. Only Twisted-Pair 120 ohms Impedance cable is suitable. Use of other cables with different impedance or poorly twisted will cause signal distortion and loss of data. The choice of cable will effect the distance and the data transfer rate.

2.0 Operating Mode

2-1 RS-422 Optical Isolator Design


The Model 8381 - Optical Isolator has an internal opto coupler system providing optical isolation between the two interfaces (RS-422). Each RS-422 interface module carries its own (independent) common signal with separate ground references.

2-2 RS-422 4 Wire Cable Requirements

The principle of a RS-422 connection is based on the use of Transmit and Receive pairs. Each line needs a termination load at its receive end. The Model 8381 is effectively located at the ends of the connection and should be terminated with 120 Ohms.

3.0 Connection

3-1 Connection - Functional


3-2 Connection - Physical


NOTE : Connection of T- and T+ (I/O A) is to a screw terminal block which is located on the side of the unit. A screwdriver is needed to insert the wire into its position.

4.0 Parameter Selection

Dip Switches

The Model 8381 incorporates a micro-controller. Many of the parameters controlling the micro are established via dip switches. These settings are marked mandatory and should not be changed. Other switches that are user selectable are appropriately marked by an X.

4-1 Dip-Switch S1


10 : Mandatory
10 : Mandatory
001 : Mandatory
0 :
1 :
Common not connected to Earth (I/O B)
Common connected to Earth by 100 Ohms

4-2 Dip-Switch S2, I/O B


0 : Mandatory
01 : Mandatory
0 :
1 :
No PULL-UP on Receive - (R -)
PULL-UP on Receive - (R -)
0 :
1 :
No PULL-DOWN on Receive + (R +)
PULL-DOWN on Receive + (R +)
00 :
11 :
Terminal Loads not connected
Terminal Loads connected
0 :
1 :
Common not connected to Loads
Load Mid-point towards common

4-3 Dip-Switch S3

Dip switch S3 should be set as follows:


4-4 Dip-Switch S4, I/O A RS-422 4-wire


0 :
1 :
No PULL-UP on Receive - (I/O A)
PULL-UP on Receive - (I/O A)
0 :
1 :
No PULL-DOWN on Receive + (I/O A)
PULL-DOWN on Receive + (I/O A)
00 :
11 :
Terminal Loads not connected (I/O A)
Terminal Loads connected (I/O A)
0 :
1 :
Load Mid-point not connected to signal ground (I/O A)
Load Mid-point connected to signal ground (I/O A)
0 :
1 :
Common not connected to Loads (I/O A)
Load Mid-point towards common
0 :
1 :
I/O A common not connected to Earth (I/O A)
I/O A common connected to Earth by 100 Ohms (I/O A)
0 :
1 :
I/O A common not connected to Earth (I/O A)
I/O A common connected to Earth (I/O A)

4-5 Factory Default Settings, With Terminal Loads (dark area shows switch position)





4-6 I/O B RS-422 4 wires (Functional switch operation)


4-7 I/O A RS-422 4 wires (Functional switch operation)


5.0 Specifications

Interfaces : RS-422, 4 Wires
Signal Type : Conforms to RS-422 (EIA)
Transmission : Serial asynchronous
Operating Mode : Full Duplex
Code and character format : Transparent up to 115.2 KBPS
Isolation : Optical via Opto Couplers
Dimensions : 3.1" x 1.57" x 3.35" (79 x 40 x 85mm)
Mounting : Snaps onto DIN rails -
EN 50 045
EN 50 022 European standards
EN 50 035
Power Supply : 115 Vac, 60 Hz Standard
Consumption : 2.5 W Max
Environment : Operating Temperature 0 to 70C, Storage Temperature -20 to 70 C, Humidity 10% at 90% No condensation.
Approvals: CE marked

6.0 Help

If any assistance is required please visit our  Technical Support Center.
 

Warranty

Telebyte warrants the equipment to be free from defects in material and workmanship, under normal and proper use and in its unmodified condition, for 12 months, starting on the date it is delivered for use. TELEBYTE's sole obligation under this warranty shall be to furnish parts and labor for the repair or replacement of products found by TELEBYTE to be defective in material or workmanship during the warranty period. Warranty repairs will be performed at the point of manufacture. Equipment approved for return for warranty service shall be returned F.O.B. TELEBYTE factory and will be redelivered by TELEBYTE freight prepaid, except for non- continental U.S.A. locations. These deliveries will be sent COD freight and import/export charges.

THE ABOVE WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, STATUTORY OR OTHERWISE, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TELEBYTE SHALL NOT BE LIABLE FOR ANY DAMAGES SUSTAINED BY RESELLER OR ANY OTHER PARTY ARISING FROM OR RELATING TO ANY EQUIPMENT FAILURE, INCLUDING, BUT NOT LIMITED TO CONSEQUENTIAL DAMAGES NOR SHALL TELEBYTE HAVE ANY LIABILITY FOR DELAYS IN REPLACEMENT OR REPAIR OF EQUIPMENT.

Out of warranty equipment may be returned to the Greenlawn, NY customer service facility prepaid as described above. Return shipping charges will be billed to the customer. The repaired unit will have a 90 day warranty. In those cases where "NO TROUBLE" is found, a reduced charge will be billed to cover handling, testing and packaging.

Whether in or out of warranty a Return Material Authorization number (RMA) is necessary
and can be obtained by visiting our Technical Support Center. Reference RMA number on the outside container.

Document No. 0315-0253/Rev. A

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