5
Creating Project Files—Modbus Master to Devices
28
Siemens Energy & Automation, Inc.
5 Creating Project Files—Modbus
Master to Devices
This chapter covers configuration of the DTU3005 for
Modbus master device communications with Siemens
devices. Once you have created a Modbus Master to
Devices project (see
Chapter 3
), follow the directions
in this chapter to configure the project file. Then see
Chapter 7
for directions on downloading the project to
the DTU3005.
5.1
Application Description
The Modbus Master to Devices application allows a
Modbus master (usually a SCADA system) to control
and monitor up to 32 SEAbus devices or Siemens pro-
tective relays. In this application, the DTU3005B acts
as a slave, and all communications with the Modbus
Master are initiated by the master device itself. The
DTU3005B converts Modbus requests received into
requests to access and control data on the Siemens
devices. Registers are assigned for each device in the
Holding Register range (40000 to 49999, where regis-
ter 40001 is the first to be used). The Modbus Master
accesses real-time data from the Siemens devices by
reading these registers, and sends commands by writ-
ing to these registers. Refer to
Figure 5.1
for a matrix
representation of these registers.
Figure 5.1
Modbus Master to Devices Project—Data Registers Matrix
