Siemens SIMATIC NET Operating Instructions Manual page 14

Description of the device
2.5 LED display
LED color LED status
Red Flashing
Red/green Flashing
14
Meaning
Transmission rate not yet detected because:
There is no transmitting bus node
•
There is no connection to a partner module that is trans-
•
mitting frames
Send and receive FO cable swapped over
•
Transmission rate does not correspond to the PROFIBUS
•
standard
There is only one single active bus node connected that
•
is only transmitting tokens to itself. After activating a sec-
ond bus node, the display must change (token frames
alone are not enough to set the transmission rate).
The connected RS-485 segment is only terminated at one
•
end
No connection to the master
•
– FO cable interrupted
– Problem on the RS-485 interface (bus short-circuit)
Transmission rate detected but:
The slot time of the network could not yet be detected
•
(network parameter HSA set too low, there is no transmit-
ting bus node)
One optical channel is set to the "redundant optical ring"
•
mode but the second one is not (this mode must always
be set on both optical channels)
The slot time of the network is set too low
•
Operating Instructions, 01/2020, C79000-G8976-C270-06
Signaling contact
Does not signal
Does not signal
Optical link module