Siemens SIMATIC S5 ET 200U - Using Leds to Diagnose Problems

6-35
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
6.4 Using LEDs to Diagnose Problems
Figure 6-3 Fault LEDs on the ET 200U Interface Module
The following table explains the meanings of the fault LEDs:
Table 6-39 LED Fault Messages from ET 200U
LED Optical
Signal
Explanation
RUN Lit Normal operation (load voltage supply
available)
BUS–FAULT Lit
 No FMS link established
The following three fault messages are
valid only if a DP master is also con-
nected to the bus:
 Response time has run out and the ET
200U was not addressed.
 During system start–up or power up:
ET 200U not yet parameterized.
 No connection between bus and
ET 200U.
IM–FAULT Lit or flas-
hing
Fault in the I/O bus
(e.g. bus unit defective)
BUS–FAULT
und
IM–FAULT
Lit
Hardware fault in the ET 200U interface
module
BUS–FAULT
und
IM–FAULT
Flashing
The configured station address is not within
the permitted range (1 to 125)
ET 200U(DP Standard/FMS): Modes, Settings and Comm. Capabilities of IM 318–C