Emerson SI-PROFIBUS

Unidrive M SI-PROFIBUS User Guide 7
Issue Number: 3
Safety
information
Introduction
Mechanical
installation
Electrical
installation
Getting
started
Parameters GSD Files Cyclic data
Non-cyclic
data
Control and
status words
Diagnostics
PROFIdrive
profile (V4)
Advanced
features
Legacy
features
Glossary of
terms
Index
2 Introduction
2.1 What is PROFIBUS-DP?
PROFIBUS-DP (Decentralized Peripheral) is a networking system which falls into the
generic category of fieldbus. Fieldbuses are generally defined as industrial networking
systems that are intended to replace traditional wiring systems. Figure 2-1 shows the
traditional cabling requirements to transfer signals between 2 slaves and a master.
Figure 2-1 Traditional cable layout
Table 2.1 details how the wiring is used to communicate data between the master and
the slaves. Each signal that is communicated requires one signal wire giving a total of
66 signal wires plus a 0V return.
Table 2.1 Traditional wiring details
A fieldbus topology such as PROFIBUS-DP allows the same configuration to be
realized using only two signal wires plus a shield. This method of communication saves
significantly on the amount of cabling required and can improve overall system reliability
as the number of interconnections is greatly reduced.
Hardwired master
Slave Number
1
Slave Number
2
Analog 1 Analog 2
Digital 1ADigital 1B
Digital 2A Digital 2B
Digital 1A Digital 1B Digital 2A Digital 2B
Analog 1 Analog 2
Number of
signals
Type Source / Destination Description
16
digital Inputs slave 1 to master status signals
digital outputs
master to slave 1
control signals
1 analog output control signal
16
digital inputs slave 2 to master status signals
digital outputs
master to slave 2
control signals
1 analog output control signal