Physical Connection; Introduction - Siemens 7SR12 Argus Manual

2. Physical Connection

2.1 Introduction

The relay provides one "Front" USB communication interface (Com2) located on the fascia and one RS485 (Com1)
located on the "Rear" as standard.
A detailed description of the ports is given below.
COM1-RS485: This port can be used for IEC60870-5-103, MODBUS-RTU or DNP3 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.
COM2-USB: This port is used for IEC60870-5-103 (default setting) communication with the Reydisp
software.
An ASCII protocol is also available through this port, the main use of this protocol is to
allow the Relay firmware to be updated via the front connection.
MODBUS-RTU or the optional DNP3 protocols are also available.
COM3-LAN: When the Ethernet module is fitted, in addition to IEC61850 a LAN connection is provided
to allow the Reydisp software to connect to the Relay via the network. This port only
supports the IEC60870-5-103 protocol.
Any or all serial ports can be mapped to the IEC60870-5-103, DNP3 or MODBUS-RTU protocol at any one time,
protocols available will depend upon relay model. The optional ethernet port uses IEC 61850 protocol and can also
provide an IEC 60870-5-103 protocol connection to Reydisp. Any port not required can be disabled by setting its
protocol to OFF.
When connecting to Reydisp Evolution software the protocol for the relevant port should be set to IEC60870-5-103.
© 2017 Siemens Protection Devices Limited
Chapter 4 - 7SR120 · Data Communications Definitions
Chapter 4 - Page 7 of 84