Profibus Dp Communication - Siemens SINUMERIK 840Di Manual

PROFIBUS DP Communication

7.1 General
PROFIBUS DP
PROFIBUS DP with
Motion Control
extension
 Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition
PROFIBUS DP is an international, open field bus standard laid down in the Eu-
ropean field bus standard EN 50170 Part 2. PROFIBUS DP is optimized for fast,
time-critical data communication on the field level.
The components communicating on PROFIBUS DP are subdivided into master
and slave components.
1. Master (active node)
Components operating on the bus as master determine the data exchange
on the bus and are therefore also designated active nodes.
Masters divide into two classes:
S
DP master, class 1 (DPMC1):
This is the designation for central master devices exchanging informa-
tion with the slaves within defined message cycles.
Examples: SIMATIC S5, SIMATIC S7, etc.
S
DP master, class 2 (DPMC2):
These are devices for configuring, starting up, operating and watching
during running bus operation.
Examples: Programming devices, operator control and monitoring de-
vices
2. Slaves (passive nodes)
These devices may only receive messages, acknowledge them and transfer
message to the master on its request.
Examples: Drives, I/O modules.
Communication between SINUMERIK 840Di (NC and PLC), as the master, and
the slave components on PROFIBUS DP is based on PROFIBUS DP with the
MotionControl extension.
The MotionControl extension is characterized by:
S
Configurable equidistant DP cycle
S
Synchronization of the DP slaves by the DP master using a GlobalControl
message frame in every DP clock
S
Automatic maintenance of the equidistant clock by the DP slaves during a
short communication failure.
References: /PPA/ PROFIDrive Profile Drive Technology Version 3,
Draft V1.4.2, 01. September 00
7
7-203