Siemens S5-135U/155U - Manual (Page 300)

7-10
System Manual
C79000-G8576-C199-06
7.2.1 Indicators and Controls
IM 301:
Fault LEDs
When the CPU is restarted, the red LED 1 and/or LED 2 lights up if the
internal supply voltage (5 V DC) or external load voltage (24 V DC) fails.
The IM 310 has no indicators or controls.
Fault
Fault
50
34 18
33 17
1
50 33 17
34
18
1
50
34 18
33
17
1
50 33
17
34
18
1
IM 301 IM 310
Fault
Centralized
Connection
Distributed
Connection
Figure 7-7 Front Plate of the IM 301 and IM 310
Interface Modules