Chapter 4 - 7SR45 Data Communications Definitions
© 2018 Siemens Protection Devices Limited
Chapter 4 Page 4 of 20
Section 2:
Physical Connection
2.1
Introduction
The relay provides one “Front” USB communication interface located on the fascia and one RS485
located on the “Rear” as standard.
A detailed description of the ports are given below.
RS485:
This port can be used for IEC60870-5-103 and MODBUS-RTU communications
to a substation SCADA or integrated control system or for engineer remote
access. This port can also be used for connection to Reydisp software.
USB:
This port is used for IEC60870-5-103 (default setting) communication with the
Reydisp software.
Any or all serial ports can be mapped to the IEC60870-5-103 or MODBUS-RTU protocol at any one
time, protocols available will depend upon relay model.
When connecting to Reydisp Evolution software the protocol for the relevant port should be set to
IEC60870-5-103.
2.2
USB Interface
The USB communication port is connected using a standard USB cable with a type B connection to
the relay and type A to the PC.
The PC will require a suitable USB driver to be installed; this will be carried out automatically when the
Reydisp software is installed. When the Reydisp software is running with the USB cable connected to
a device an additional connection is shown. Connections to these devices are not shown when they
are not connected.
The USB communication interface on the relay and its associated settings are located in the Data
communications menu. When connecting to Reydisp using this connection the default settings can be
used without the need to first change any settings.
Access to the communication settings for the USB port is only available from the relay front fascia via
the key pad setting menu COMMUNICATIONS MENU.
Setting
Name
Range/Options
Default
Setting Notes
USB
Protocol
OFF
IEC60870-5-103
MODBUS-RTU
IEC60870-5-103
Reydisp software
requires IEC60870-5-
103
USB
Stn
Addr
0 to 254 for IEC60870-5-103
1 to 247 for Modbus RTU
1
An address within the
range of the relevant
protocol must be given
to identify the relay.
Each relay in a network
must have a unique
address.
USB Mode Local
Local or Remote
Remote
Local or Remote