RS-422 Connections

APPENDIX B: RS-422 CONNECTIONS

Serial Server DB-9 Pin-outs in RS-422 Mode

 

 

 

 

RS-422

 

 

DB9M

Signal Name

Direction

RS-422

Pin

Receive Data A (−)

In

RXDA (−)

1

Receive Data B (+)

In

RXDB (+)

2

Transmit Data B (+)

Out

TXDB (+)

3

Transmit Data A (−)

Out

TXDA (−)

4

Signal Ground

---

GND

5

Clear to Send A (−)

In

CTSA (−)

6

Clear to Send B (+)

In

CTSB (+)

7

Request to Send B (+)

Out

RTSB (+)

8

Request to Send A (−)

Out

RTSA (−)

9

Figure 66. RS-422 Connections in a DB-9 Connector

Manual Documentation Number: ESP901-902-3704

Appendix B

75

RS-422 Connections

Serial Server pin-out

 

 

RS-422

in RS-422 mode

 

 

Device

RS-422 Signal Names

DB-9

Connections

Signal

 

 

Pin#

 

 

Receive A (-)

RXDA(-)

1

 

TDA(-)

Receive B (+)

RXDB(+)

2

 

TDB(+)

Transmit B (+)

TXDB(+)

3

 

RDB(+)

Transmit A (-)

TXDA(-)

4

 

RDA(-)

Ground

GND

5

 

GND

 

Clear to Send A (-)

CTSA(-)

6

 

RTSA(-)

Clear to Send B (+)

CTSB(+)

7

 

RTSB(+)

Ready to Send B (+)

RTSB(+)

8

 

CTSB(+)

Ready to Send A (-)

RTSA(-)

9

 

CTSA(-)

Figure 67. RS-422 Connections with Flow Control

In the RS-422 mode, TXD lines are outputs and RXD lines are inputs. Connect the Serial Server TXDB(+) line to the RXDB(+) line of the serial device, and the Serial Server TXDA(-) to the RXDA(-) of the serial device.

If Flow Control is set for RTS/CTS, connect the Serial Server RTSB(+) to CTSB(+) of the serial device and the Serial Server RTSA(-) line to the CTSA(-) of the serial device. Connect from the Serial Server CTSB(+) line to the RTSB(+) of the serial device and from the Serial Server CTSA(-) line to the RTSB(+) line of the serial device.

If connecting to Receive Only RS-422 devices, connect from the Serial Server TXDB(+) and TXDA(-) lines to the receive pairs on all serial devices.

Ground is signal ground and provides a common mode reference for the RS-422 Receiver and Transmitters.

Note:

The RS-422 mode can be used for full duplex 4-wire RS-485 operation provided that the serial server is acting as a sole master connecting to all the slave devices, and all slave devices share the Receive signal lines to the master. Set Flow Control for none, and omit connections to RTS/CTS line pairs.

76

Appendix B

Manual Documentation Number: ESP901-902-3704

B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104

www.bb-elec.com

B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104

www.bb-elec.com

B&B Electronics Ltd – Westlink Commercial Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445

www.bb-europe.com

B&B Electronics Ltd – Westlink Commercial Pk – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445

www.bb-europe.com

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B&B Electronics ESP901E, ESP902E manual Appendix B RS-422 Connections, Serial Server DB-9 Pin-outs in RS-422 Mode

ESP902E, ESP902, ESP901E specifications

B&B Electronics offers a series of industrial-grade Ethernet serial servers known as the ESP901E, ESP902, and ESP902E. These devices are specifically designed to connect serial devices to an Ethernet network seamlessly, enabling effective communication and data transfer across various applications.

The ESP901E is engineered for single serial port applications, providing an easy and effective way to connect a serial device to a network. It supports various serial communication protocols, including RS-232, RS-422, and RS-485, making it versatile for a range of devices. One of its standout features is the ability to support 10/100 Mbps Ethernet connectivity, ensuring a reliable and high-speed network connection. Additionally, the ESP901E supports various network protocols, including TCP/IP and UDP, allowing users to integrate the device easily into their existing network infrastructure.

Moving to the ESP902, this model provides dual serial port capabilities, making it ideal for applications requiring the connection of multiple devices. Like the ESP901E, it supports common serial interfaces and offers the same 10/100 Mbps Ethernet connectivity. This flexibility enables it to cater to more complex systems where multiple serial devices need to be integrated into a single network environment. Furthermore, the ESP902 is equipped with features such as automatic baud rate detection, making configuration straightforward and reducing installation time.

The ESP902E enhances the capabilities of the ESP902 with additional features such as enhanced security protocols. It includes support for SSL and SSH, ensuring secure data transmission across the network. This added security layer is crucial for applications that handle sensitive information or require secure communication channels. The ESP902E maintains the user-friendly nature of its predecessors while integrating more advanced features suitable for modern industrial applications.

All three models boast rugged designs suitable for harsh environments, making them perfect for industrial applications without compromising performance. With an extensive operating temperature range and robust housing, these devices can withstand the rigors of factory floors and outdoor installations.

Overall, the ESP901E, ESP902, and ESP902E from B&B Electronics collectively serve to bridge the gap between serial communications and Ethernet networks, supporting various industrial applications while ensuring seamless integration, versatility, and security. Whether for simple single-port connections or more complex multi-port setups, these devices are designed to meet diverse connectivity needs with efficiency and reliability.