122 Diagnostics
WAGO-I/O-System 750
750-370 PROFINET IO Fieldbus Coupler
Manual
Version 2.0.0
Table 57: Blink Code Table for the I/O LED Signaling, Error Code 3
Error code 3: “Protocol error, internal bus”
Error
Argument
Error Description Solution
-
Internal data bus
communication is
faulty, defective
module cannot be
identified.
- Are passive power supply modules (750-613) located in the
node? -
1. Check that these modules are supplied correctly with
power.
2. Determine this by the state of the associated status LEDs.
- Are all modules connected correctly or are there any
750-613 Modules in the node? -
1. Determine the faulty I/O module by turning off the power
supply.
2. Plug the end module into the middle of the node.
3. Turn the power supply on again.
4. - LED continues to flash? -
Turn off the power supply and plug the end module into
the middle of the first half of the node (toward the
fieldbus coupler).
- LED not flashing? -
Turn off the power and plug the end module into the
middle of the second half of the node (away from the
fieldbus coupler).
5. Turn the power supply on again.
6. Repeat the procedure described in step 4 while halving
the step size until the faulty I/O module is detected.
7. Replace the faulty I/O module.
8. If there is only one I/O module on the fieldbus coupler
and the LED is flashing, either the I/O module or fieldbus
coupler is defective. Replace the I/O module with a
pretested, properly functioning I/O module. If the LED
no longer flashes, the replaced I/O module was faulty.
Replace this I/O module.
9. If the LED continues to flash, the fieldbus coupler is
faulty. Replace the fieldbus coupler.