RS232 to RS422 - RS485
Interface Converter

The Model 365 multimode interface converter allows operation in compliance with RS-485 or RS-422 equipment, and RS-232.

Model 365 - RS-232 to RS-422/RS-485 Interface Converter
  • User Selectable RS-422 or RS-485
  • User Selectable 2 or 4 Wire RS-485
  • DataSpyŽ LCD Display
  • Intelligent Control of RS-485 Transmitter and Receiver
  • DTE/DCE Compatible
  • Data Rates Up to 115.2 KBPS

Product Description

The Model 365 multimode interface converter allows operation in compliance with RS-485 or RS-422 equipment, and RS-232. When operating as RS-485 the Model 365 has an "intelligent" mode which provides control of the RS-485 line. Operating as an RS-232 to RS-422 interface converter, the Model 365 converts full duplex data, TD and RD, between RS-232 and RS-422. As an RS-232 to RS-485 converter the Model 365 can be configured as a 2 wire or a 4 wire converter. For RS-485 half duplex protocol, the Model 365 can be configured to control its data flow in one of two ways. The first is via the use of RTS, pin 4, of the RS-232 port. The second is to turn it on when TD data is applied to the RS-232 port.

The Model 365 includes Telebyte's unique DataSpy LCD display, which provides the user with status information regarding the operation of the device. The LCD is useful during the installation and checkout and whenever there are suspected problems. The graphic display presents the user with live status of the transmit and receive data signals, TD and RD, and control signals, CTS, RTS, DSR, DCD, and DTR.

Model 365 Specifications  
  • Interface: RS-232: Conforms to RS-232 and CCITT V.24. Pins 2 and 3, Transmit and 
  • Receive data, switch selectable. Pins 4, RTS, tied to Pin 5, CTS. Pins 6 (DSR), 8 (DCD) and Pin 20, (DTR) are connected together RS-485: Conforms to RS-485 RS-422: Conforms to RS-422
  • Connectors: RS-232: DB25 male RS-485/RS-422: 5 position terminal block
  • Indicators: LCD for TD, RD, CTS, RTS, DCD, DTR, DSR
  • Switches: DTE/DCE switch selectable for reversing TD and RD; 5 position dip switch: set RS-485 2 or 4 wire, RS-422 and termination
  • Data Rate: 0 to 115.2 KBPS
  • MTBF: 596,000 Hours (68 Years)
  • Power: 115VAC @ 60Hz (220VAC/50Hz optional)
  • Size: 2" x 4.1"L x 0.8"H
  • Environment: 0° to 50° C, 0% to 95% RH

Model 365 Application Notes


Data processing equipment in the office, on the factory floor and across the campus may come in a variety of 'flavors,' embracing terminals, badge readers, alarm equipment and all types of manufacturing and laboratory instruments. The serial EIA-232 interface is perhaps the most widespread interface found on different data devices. It is perhaps the most universally found debarkation point for bringing data into and out of these devices. Data communication connections between such equipment in the premises environment can often be accomplished by merely connecting interfaces together by a cable.

One problem arises though. While the EIA-232 interface is the most widespread interface, it is not ubiquitous. There are other interfaces, notably RS-422 and RS-485. The need often arises to interconnect data devices having different interfaces. Usually this need is to interconnect a device having the popular EIA-232 interface with a device having something else like RS-422.

Interface conversion is a straightforward task. However, when you have a heterogeneous environment with different types of equipment having different types of interfaces the whole management problem begins to get 'messy.' The network manager would like to have one interface converter type around to use in these situations and use it for whatever type of conversion is needed. The Model 365 is a neat solution to maintaining control and avoiding a mess.

The Model 365 allows conversion between EIA-232 and either RS-422 or RS-485 in just 1 box. The user simply selects either RS-422 or RS-485 for the conversion. Furthermore, the user can select either 2 or 4 wire RS-485. The universality of this converter goes even further. If RS-485 half duplex is desired for conversion the Model 365 can be configured to control data flow in either of two ways. It can use RTS of the EIA-232 interface or it can turn on when TD is applied to the EIA-232 interface.

The Model 365 can even give you further flexibility in configuring your premises data communications network. It may be that you have procured or inherited all data devices with the same interface and that this interface is the widespread EIA-232 interface - what else? You put these inherited devices aside in some storage area. However, some time later you (and the emphasis is on 'you') decide that you need to interconnect these types of devices in an RS-485 type 'polling' network. You realize that your inherited devices do not have the RS-485 interface demanded. But, you also realize that the Model 365 placed at each of your data devices gives it an RS-485 interface and allows you to implement the network you want and without having to go out and buy expensive data equipment with the needed interface built-in.

This is exactly the situation in the illustration. Here we have a minicomputer on the left, a plotter in the center and two terminals on the right. They were all inherited by a laboratory manager in a well-known company. Each of these devices only came with the EIA-232 interface. After some period of time the laboratory manager decided that for his installation a network was needed where a minicomputer would control a plotter and communicate with two terminals and that the control and communication would be effected by a polling protocol. RS-485 networking was perfect for this situation. However, the laboratory manager did not have data devices with the RS-485 interface. He also did not want 'to bust' his annual budget by going out and procuring new devices that had this interface. Instead he went to his storage area and pulled out the inherited devices with the EIA-232 interfaces. He then went and purchased a Model 365 to attach to each data device and gave it an RS-485 port - an inexpensive solution to his networking needs.


Model Description Product Info
365M Multimode RS-422/RS-485 to RS-232 Interface Converter - Male Connector see manual  
365M-220 Multimode RS-422/RS-485 to RS-232 Interface Converter - Male Connector - 220 Volts see manual  
365F Multimode RS-422/RS-485 to RS-232 Interface Converter - Female Connector see manual  
365F-220 Multimode RS-422/RS-485 to RS-232 Interface Converter - Female Connector - 220 Volts see manual  


301-924-7400 EXT 25

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