RS232-RS485 DB9 Converter - RMC/9R

Power supply
Self-powered via DB9
Power consumption
1 W
Serial transmission data rate
0 - 250 kbps (automatic)
RS232 connector
D-sub (DB9)

RMC/9R is a RS232-RS485 DB9 converter that converts from RS232 serial standard (with a DB9 connector) to RS485 (with a 3-pin Mini XLR connector).

This industrial adapter is self-powered via the RS232 D-sub connector. It can be used to enable communication between a PC or industrial equipment and an RS485 serial bus, connecting from a DB9 connector with screw terminals to a 3-pin Mini XLR connector.

It is completely protocol-transparent, so it can be used with any proprietary protocol that operates over RS232. Data direction is completely automatic.

The device is fully Plug & Play and requires no drivers or DIP switches. The RS232-RS485 DB9 converter operates in half-duplex mode and automatically detects data direction and baud rates up to 250 kbps, making it easy to install in any new or existing system.

Technical specifications

Main features

Power supplySelf-powered via DB9
Power consumption1 W
Serial transmission data rate0 - 250 kbps (automatic)
RS232 connectorD-sub (DB9)

RS232

Communication typeFull duplex
RX input voltage1.5 V low input threshold - 1.8 V high input threshold (± 25 V max)
TX output voltage± 5 V (± 5.4 V max)
ESD performance RX / TX± 15 kV (Human Body Model) - ± 8 kV IEC61000-4-2 contact discharge

RS485

Communication typeHalf Duplex on balanced line
Data directionAutomatic
Maximum bus voltage± 42 V DC
Common mode range± 25 V DC
ESD protection± 15 kV (Human Body Model) - ± 8 kV IEC 61000-4-2 contact
Surge protectionIntegrated TVS: ± 3 kV IEC 61000-4-5 (surge) - ± 4 kV IEC 61000-4-4 (EFT)
Slew rateLimited, to have an error-free transmission

Mechanical features

Dimensions48 mm x 31 mm x 25 mm

Working conditions

Degree of protectionIP20
Operating temperature-20 °C to +50 °C
Storage temperature-40 °C to +80 °C

RMC/9R is a RS232-RS485 DB9 converter that converts from RS232 serial standard (with a DB9 connector) to RS485 (with a 3-pin Mini XLR connector). This industrial adapter is self-powered via the D-sub connector. It can be used to enable communication between a PC or industrial equipment and an RS485 serial bus, connecting a DB9 connector with screw terminals to a 3-pin Mini XLR connector.

The device is fully Plug & Play and requires no drivers or DIP switches. The RS232 serial port operates in full-duplex mode, while the RS485 serial port operates in half-duplex mode, with automatic data direction. The RS232-RS485 DB9 converter automatically detects baud rates up to 250 kbps, so it can be easily installed in any new or existing system.

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Use cases

The very compact size of this converter allows it to be installed in tight spaces where there is physically no room for a traditional DIN-rail converter. Another scenario in which this RS232-RS485 DB9 converter may be necessary is when a machine has only a DB9 (or, more precisely, D-sub) port and can communicate only through that port. This converter can be secured to the machine on the D-sub side with screws for maximum communication reliability.

If it is necessary to isolate the communication to protect the computer from minor or moderate interference, an isolated converter such as IMC/9R is recommended; however, it must be powered externally with a DC power supply ranging from 5 V to 12 V DC. This converter can be powered by 5 V to 12 V DC via a standard jack and can be connected, for example, to a USB port or using a custom power cable.

In industrial environments, communication interference is common, and it is good practice to protect devices that communicate externally.

Protocol

The RMC/9R RS232-RS485 DB9 converter is completely protocol-independent. This means that the converter is transparent to the communication and can be used with any proprietary protocol.

This is possible because the converter operates at the logic level rather than at the protocol level. Therefore, this RS232-RS485 DB9 converter can be used with any computer or machine that communicates via a DB9 port using the RS232 serial standard.

Data direction is completely automatic.

Versatility

The RS232-RS485 DB9 converter is also available with RTS data direction or with different connectors. RSC/9R converter, for example, is functionally identical to RMC/9R, but data direction is controlled by software (RTS, Request To Send). IMC/9R and ISC/9R feature an RS485 interface isolated up to 50 V, should this be required for added protection, with automatic data direction or RTS, respectively.

The DFP/9S and DFP/9A industrial serial converters have a synthetic optical fiber output with a screw-type connector to electrically isolate the equipment. All combinations of serial standards, optical fiber, and power supply are available in the catalog, while special requests (such as higher baud rates) can be made via the contact form.

Request information about RMC/9R

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