1.0 General Description

The Model 265, Opto-Isolated RS-232 to RS-422 Interface Converter, provides total isolation between RS-232 based equipment and RS-422 equipment. The Model 265 comes equipped with a DTE/DCE switch and TD and RD LED's to verify operation.

2.0 Specifications

2.1 Interface : Conforms to EIA RS-232 and RS-422 specifications.

2.2 Connectors
2.2.1 RS-232 : DB25M
2.2.2 RS-422 : 5 position terminal block and RJ-11

2.3 Data Rate : 0.3 to 19.2 KBPS

2.4 Switches : DTE/DCE switch for reversing TD & RD.

2.5 Indicators : TD and RD LED's

2.7 Operating Distance : The following table gives maximum distance as a function of baud rate (using 24 AWG wire).

2.8 Power : 115VAC @ 60 Hz (220 VAC @ 50 Hz optional)

2.9 Size : 2" W x 4.75" L x 0.875" H (50.8mm x 88.9mm x 22.2mm)

2.10 Environment : 0° to 50° C, 5% to 95% relative humidity

2.11 Block Diagram

3.0 Installation

3.1 RS-232 Interface : The digital interface for the Model 265 is a male DB25 connector.

3.2 RS-422 Interface
3.2.1 Terminal Block - The Model 265 is supplied with a 5 position terminal block marked T+, T-, R+, R-, and G. The Model 265 has built in surge suppression that is discharged to the ground connection on the 5 position terminal block, G. When connecting the G terminal to earth ground, the connection between the 265 and earth ground should be less than 6 feet and connected using 14 gauge wire.
3.2.2 Phone Plug - The Model 265 is equipped with a standard RJ-11 modular phone connector, only the 4 middle pins are used. The designation of the wires is shown below:

4.0 Operation

The Model 265 will perform full duplex conversion of the TD and RD signals. The RS-422 equipment is connected to the 265 through the 5 position terminal block marked G, R-, R+, T-, and T+. The R+ and R- are the receiver inputs into the 265 and T+ and T- are the transmitter outputs. When con-necting the 265 to other RS-422 equipment, the T+ and T- should be one twisted pair while R+ and R- should be an-other. The G connection is connected to Pin 1, Frame Ground, on the RS-232 port.

5.0 Troubleshooting

The following is a list of possible problems that may arise during the installation and solutions to these problems:

1. The data being received is garbled?
a) The DTE/DCE switch is not set properly (see Section 3).
b) The equipment that the Model 265 is connected to does not have the communication parameters set the same.
c) T+ and T- are reversed going to R+ and R-. On the Model 265 look at the RD LED, if it is ON continuously then the leads are reversed.
d) One of the four wires is broken.
e) Wires are not paired properly : T+ and T- should be one twisted pair and R+ and R- are the other pair.

2. No data is being received.
a) Customer equipment not connected to the 265.
b) The DTE/DCE switch is not set properly (see Section 3).
c) One or more wires between the modems are open.
d) Link connection exceeds maximum specified distance.
Operation of the Model 265 can be verified if one of the de-vices to which the modem is attached is capable of operating in a full duplex mode (such as a terminal or a PC using communications package such as Procomm). Connect the 265 to the terminal through the RS-232 connector and make the following loopback connections at the analog interface.

If the modem is functioning correctly, any data entered on the keyboard will appear on the terminals screen.

6.0 RS-232 Pin Number Assignments

7.0 Power

7.1 RS-232
Power for the RS-232 side of the Model 265 is derived from the RS-232 equipment connected to it. The Model 265 will derive the necessary power from the incoming data line or any one of the control signals; RTS, CTS, DSR, DCD, or DTR.

7.2 RS-422
The RS-422 side is powered by a small, wall mounted trans-former that supplies 9 VAC @ 500 mA. Note : The transformer must be connected to the Model 265, through the 3.5mm connector located on the side of the unit, before plugging the transformer into the wall.

8.0 Help

Assistance can be obtained by visiting 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. Assistance can be obtained by visiting our Technical Support Center.

Document No. 0315-0237/Rev. A

Model	Product Info
265