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5 led indicators and troubleshooting, 1 led indicators – Siemens SIMATIC NET PROFIBUS User Manual

Page 421

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5.1 LED Indicators

25

5 LED Indicators and Troubleshooting

Version 1.0 8/00

5 LED Indicators and Troubleshooting

Fig. 14: LED indicators on the front plate

CH 1

System

PROFIBUS OLM

CH 2

CH 3

GND

Receive

Signal

Intensity

CH 2 CH 3

LED indicators

Possible causes

– The transmission rate has been recognized and the power supply is in order

– Power supply has failed (total failure*)
– Power supply connected incorrectly
– Module defective

Transmission rate has not yet been recognized
– No transmitting bus subscriber present
– No connection to a partner module sending frames
– Send and receive optical fibers have been transposed
– Transmission rate does not correspond to the PROFIBUS standard
– Only one active bus subscriber is connected, which is only sending tokens to

itself. The indicator must switch over after a second bus subscriber has been
activated (token frames on their own are not enough to set the transfer rate).

– The connected RS 485 segment is only terminated at one end.

Transmission rate recognized but
– the network slot time could not be determined (network parameter HSA is set

too low, no transmitting bus subscriber present)

– one optical port is set to ”Redundant optical ring“ mode, but not the second

(this operating mode must always be set at both optical ports)

– the slot time of the network configuration is too short

* failure of both power supply sources with redundant infeed

LED Indicator

System

lights green

not lit

flashes red

flashes red /green

Signaling contact

no signal

signal

no signal

no signal

5.1 LED Indicators