Description of the device
2.5 LED display
Optical link module
16 Operating Instructions, 01/2020, C79000-G8976-C270-06
2.5.4 LED "CH2"/"CH3" - optical
Mode "bus with fiber-optic link monitoring and "redundant optical ring"
- Off Transmission rate not yet detected - "System" LED flashes
red
• There is no transmitting bus node
• Send and receive FO cable swapped over
• No partner module connected or partner module is not
turned on
• Connected partner module fault
Does not signal
Transmission rate has been detected - "System" LED lit
green
• If the "redundant optical ring" mode is set, the optical
channel operates as a standby channel. There is no prob-
lem in the OLM or on the fiber-optic cable.
• If one of the modes "bus with fiber-optic link monitoring
..." is set, no PROFIBUS frames are received on the opti-
cal channel. There is no problem in the OLM or on the fi-
ber-optic cable.
Yellow Lit PROFIBUS frames are being received on the optical chan-
Does not signal
Yellow Flashing Transmission rate has been detected - "System" LED lit
green or flashes red/green
• There is no transmitting bus node (fiber-optic cable link is
okay)
Does not signal
Red Lit
• Send and receive FO cable swapped over
• No partner module connected or partner module is not
turned on
• Connected partner module fault
• Transmission time exceeded by the connected partner
module
• Interrupted FO cable
• FO cable section to partner module longer than allowed
• Fiber-optic cable connector has a loose contact
• FO cable fiber is loose in the FO cable plug
• If the channel LED of the two OLMs involved continues to
be lit red even after eliminating a FO cable problem in the
redundant optical ring, check that the setting of the HSA
parameter as described in the section "Ring topology
(Page 59)" is correct
Signals