4.
Corrective action
4.1
LED indications
Figure 10:
LEDs on FO coupler
[BA] Bus active (yellow)
[U]
L
Operation (green)
[F]
Fault channel 1/2 (multicolour) – ring coupler only
Table 4:
Summary of functions
Function
Co-
lour
LED
LED flackert:
Data from RS485 channel are transmitted via the optical interface.
yellow
BA
LED is illuminated:
Power supply (24 V DC) for FO coupler is available
Internal operating voltage (5 V) is available.
green
U
L
Ring topology only:
This fault LED can be used to check the FO connections. Ein Profibus Master ist hierzu
nicht erforderlich
F
LED is illuminated in red:
Channel 1 receives no signal.
red
LED is illuminated in yellow:
Channel 2 receives no signal.
yellow
LED is illuminated in orange:
Both channels do not receive any signal.
oran-
ge
LED is not illuminated:
Input cables to the two adjacent FO couplers are in perfect condition.
–
Information
If the fault LED [F] is illuminated (red, yellow or orange), the indication is sent at the
same time via display and Profibus DP:
Wrn FOC
.
Wrn FOC
indication can be read
via fieldbus interface in the process representation input (byte 19). For an overview
and a detailed description of all input data, refer to Manual (Device integration field-
bus) AC 01.2/ACExC 01.2. Limitation: The
Wrn FO cable budget
and
Wrn FOC
connection
indications represented in byte 20 are not generated for explosion-proof
version with FO cables.
4.2
Troubleshooting
LEDs on the FO couplers provide important information for troubleshooting. The
following tables of this chapter provide basic steps for troubleshooting and elimination
via these LEDs.
12
Corrective action
