
Introduction
III
INTRODUCTION
Until all types of devices are available with Profibus-PA systems will have to be of a hybrid nature
accepting both Profibus and conventional signals. A mixed traditional and Profibus environment is
inevitable during the transition to a Profibus technology. DC303 makes integration of Profibus and
conventional I/O easy. Discrete devices such as pressure switches, push buttons, on/off valves,
pumps and conveyors are integrated to the system over the Profibus-PA field-level network using
DC303. The DC303 remote I/O units can be distributed into the field where they are mounted close
to the conventional devices without the need to run the conventional wiring to the control room. The
DC303 is an integral part of SYSTEM302 but also it integrates into other systems supporting
Profibus.
The DC303 makes conventional analog and discrete inputs and outputs available using standard
Profibus-PA Function blocks making the system homogenous and control strategy configuration
easy as conventional I/O appears as if they were regular Profibus devices. Control loops are
implemented consistently regardless of I/O being conventional or Profibus based. Only a single
programming language has to be used.
The DC303 is a simple low-cost DIN-rail mounted unit. The DC303 is a single integrated easy to
use piece of equipment including power, control, networking and I/O under one compact device
requiring less panel space than other solutions.
Function block like Discrete Input and Discrete Output, as well FFB (Flexible Function Block)
enables the DC303 to perform logic and r control functions in the field integrating the control
strategy with other Profibus devices on the same network. Function blocks provide great flexibility in
control strategy. Conventional discrete I/O now works together with pure Profibus devices on the
same network and in the same loop. The DC303 is fully configured SYSTEM302 or any other
Profibus-PA configuration tool. Function blocks provide logic such as AND, OR, NAND etc. as well
as latches etc.
The DC303 may be installed close to the sensors and actuators, thereby eliminating long wire runs
and associated marshalling panels and cable trays for the conventional I/O, with subsequent
savings further reducing overall system cost. Use DC303 to make it possible to distribute I/O at
various locations in the field and connect them via Profibus-PA. DC303 is ideal to connect motor
control centers, variable speed drives, and electrical actuators and motor operated valves to
Profibus-PA.
Get the best result of the DC303 by carefully reading these instructions.
NOTE
In case of using Simatic PDM as the configuration and parameterization tool, Smar
recommends that the user does not apply the option "Download to Device". This function
can improperly configure the field device. Smar recommends that user make the use of the
option "Download to PG / PC" and then selecting the Device Menu, use the menus of the
transducer, function and display blocks acting specifically, according to each menu and
method for reading and writing.
WARNING
This manual applies to equipment with a serial number from 2000 onwards.
NOTE
For previous DC303 versions (with plastic cowling), pick up equivalent manual.