Communication; Introduction - Siemens Sm@rt DAS User Manual

Chapter 4
Communications

Introduction

The Sm@rt DAS controller uses MODBUS TCP/IP as its
communication protocol. A computer or SCADA system can
connect to the controller via Ethernet either directly into the
controller (Figure 4.1) for a brief period to change settings or
through a router for more permanent connections.
The DAS controller acts as a slave when interfacing with a
Building Management System or other supervisory system.
Table 4.2 shows the MODBUS system codes if integration is
needed to upstream devices.
In order to permanently connect the Sm@rt DAS to an
upstream system, the second RJ45 port of the gateway can be
used. An Ethernet switch will need to be placed between the
controller and gateway (Figure 4.2, 4.3) if several external
connections are needed.
Figure 4.2: Example of network switch
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Figure 4.1: Ethernet port
Ethernet
Gateway
Sm@rt DAS
Controller
Figure 4.3: Interface with network switch if included
To upstream
SCADA system
Network
Switch