Operating Instructions
IS1 PROFIBUS 3.00 E
- Technical alterations reserved -
33
PROFIBUS DP interface for IS1+
2.10.2.5
Updating the I/O data to the user program
In the AS, there is a third memory area for the application I/O data. This application memory area must be
updated cyclically with the memory area of the active CPU by using the user program.
The memory area for the inactive CPU output data must not be updated cyclically.
However, note that during a redundancy switching, the control command for activation and the current output
data in the same DP cycle of the hitherto inactive CPU must be transmitted.
Example 1:
Non-redundant automation system with redundant IS1+ field station
IS1+
Field station
CPU
left
CPÚ
right
I/O-Module
PROFIBUS
DP
I/O-Data
(RAM)
I/O-Data
(RAM)
Application (User program)
Logic for Redundancy
Switching
Automation system
I/O-Data (RAM)
Application
I/O-Data (RAM)
CPU left
I/O-Data (RAM)
CPU right
PROFIBUS DP Master Module