Mitsubishi Q12PRHCPU - 6.2.6 PROFIBUS-DP

6
REDUNDANT SYSTEM NETWORKS
6.2 Redundant System Network Overview
6.2.6 PROFIBUS-DP
6 - 42
1
OVERVIEW
2
SYSTEM CONFIGURATION
3
TRACKING CABLE
4
PROCEDURE FOR STARTING UP A REDUNDANT SYSTEM
5
REDUNDANT SYSTEM FUNCTIONS
6
REDUNDANT SYSTEM NETWORKS
7
PROGRAMMING CAUTIONS
8
TROUBLESHOOTING
6.2.6 PROFIBUS-DP
(1) Communication overview of the PROFIBUS-DP
In redundant system, when the PROFIBUS-DP master module detects a fault or
communication failure with DP-Slaves, the standby system master module is switched
to new control system master module and inherits the PROFIBUS communications.
(2) Operation at system switching
The PROFIBUS-DP master modules switch each system on the following cases.
• When the PROFIBUS-DP master module detects a fault
• When a communication failure with DP-Slaves is detected
Diagram 6.33 Operation of the PROFIBUS-DP Master Module at System Switching
Tracking cable
Control system
DP - Slave
DP - Slave
Standby system
Bus terminator Bus terminator
Tracking cable
New standby
system
DP - Slave
DP - Slave
New control
system
Control
system
Standby
system
Bus terminator Bus terminator
System switching
An error has
been detected
Station No. 0
Station No. 0
Station No. 1
Station No. 1
Station No. 1
Station No. 0
Continues
communications