Siemens S7-300 - Application 2: Standard Operation with High Availability

Digital modules
8.3 SM 326; DI 24 x DC 24V
Fail-safe signal modules
84 Installation and Operating Manual, 01/2010, A5E00085586-10
8.3.4 Application 2 : Standard operation with high availability
Introduction
Below are the wiring scheme and the parameter assignment of SM 326; DI 24 x DC 24V for
application 2: standard mode with high availability
Diagnostic messages, possible causes of the problem and their corrective measures are
found in tables in the chapter "Diagnostic messages of SM 326; DI 24 x DC 24V (Page 99)".
Wiring scheme of application 2 with single-channel connection of one sensor
One sensor is connected via one channel to two digital modules for each process signal. The
sensors must be connected to an external sensor supply.
/
0
',
/
0
',
0
/
9V
9V
60
',['&9
60
',['&9
Figure 8-8 Wiring scheme of the SM 326; DI 24 x DC 24V for application 2 – one sensor single-
channel connection