Application 2 : Standard Operation With High Availability - Siemens S7-300 Installation And Operating Manual

Digital modules
8.3 SM 326; DI 24 x DC 24V
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.
Figure 8-8
84
Wiring scheme of the SM 326; DI 24 x DC 24V for application 2 – one sensor single-
channel connection
Installation and Operating Manual, 01/2010, A5E00085586-10
Fail-safe signal modules