TPU2000/2000R Modbus/Modbus Plus/ Modbus TCP/IP Automation Guide
360
TELEBYTE 245 Converter
DEVICE
3 Receive Data
2 Transmit Data
2 Transmit Data
3 Receive Data
7 Ground
5 Ground
4 Request To Send
7 Request To Send
5 Clear To Send
8 Clear To Send
25 pin D shell
Female Connector
9 pin D shell
Female Connector
Cable “A”- RS 232 Cable for Connection from a NODE (DTE OR DCE) and the
TELEBYTE converter configured correctly (DTE DEVICE AND
TELEBYTE SWITCH IN DCE MODE --OR-- DCE DEVICE AND
TELEBYTE SWITCH IN DTE MODE). DATA CONTROL RTS/CTS
HANDSHAKING EMPLOYED.
Figure 2 – RS 232 Cable Pinout With Handshaking Incorporated (See Figure 1 For Dipswitch
Settings)
TELEBYTE 245 Converter
DEVICE
3 Receive Data
2 Transmit Data
2 Transmit Data
3 Receive Data
7 Ground
5 Ground
25 pin D shell
Female Connector
9 pin D shell
Female Connector
Cable “A”- RS 232 Cable for Connection from a NODE (DTE OR DCE) and the
TELEBYTE converter configured correctly (DTE DEVICE AND
TELEBYTE SWITCH IN DCE MODE --OR-- DCE DEVICE AND
TELEBYTE SWITCH IN DTE MODE). NO HANDSHAKING
Data Control via the Transmitted Data (TD) line.
Figure 3 – RS 232 Cable Connections When No Handshaking Is Used. (See Figure 1 For
Dipswitch Setting)
Power Requirements
The TELEBYTE converter is available using a variety of power supply options. The converter is supplied with a
power converter, which attaches to which attaches to the device. For current options, please consult the
TELEBYTE website.
RS485 Configuration And Cabling
The TELEBYTE converter supports RS 422, 4 Wire RS 485 and 2 Wire RS 485 connectivity. The ABB line of
protective relays supports 2 Wire RS 485 connectivity. The dipswitch settings in Figure 1 are given only for the
RS 485 two wire options. If additional configuration information is desired for RS 485 4 wire or RS 422
configuration please consult the TELEBYTE website.
The attractive feature of the TELEBYTE converter is the isolation of the RS 232 and RS 485/422 ports from
external power supplies. This feature is important especially in utility applications where external noise is an
issue.
RS 485 cabling is usually the source of most communication issues. Several issues must be remembered when
installing such a cable:
1. In attachment to ABB relays in a Utility installation, one must remember to use a cable with 3 wires and a
shield. Refer to Figures 4 through 7 for ABB recommended cables.