Diagnostics Using Leds - Siemens SIMATIC IM 151/CPU Manual

4.4

Diagnostics Using LEDs

LEDs
The RUN, STOP, ON, BF, SF and FRCE LEDs display important information on
the states of the IM 151/CPU to the user.
The IM 151/CPU has the following 6 LEDs:
"SF" LED (System Fault) for indicating the presence of a fault in the ET 200S
"BF" LED (Bus Fault) for indicating faults on the PROFIBUS-DP
"ON" LED for indicating that the ET 200S is connected to a power supply
"FRCE" LED comes on if a force request is active.
"RUN" LED for indicating that the CPU component of the IM 151/CPU is in RUN
mode
"STOP" LED for indicating that the CPU component of the IM 151/CPU is in
STOP mode
The meaning of the LEDs for CPU functionality is described in detail in Section 5.2.
"ON" LED Is Off
If the "ON" LED is off, either no supply voltage or insufficient supply voltage is
being applied to the electronic components/sensors of the ET 200S. The cause is
likely to be a defective fuse or inadequate or nonexistent system voltage.
ET 200S Interface Module IM 151/CPU
A5E00058783-01
Commissioning and Diagnostics
4-9