WAGO -I/O-SYSTEM 750 Technical Description, Installation And Configuration page 111

Error code 4 "Physical error internal bus"
Fault Argument
WAGO-I/O-SYSTEM 750
PROFINET IO
Fault Description
- Internal bus data transmission
error or interruption of the
internal bus at the buscoupler.
n* Interruption of the internal bus
behind the nth I/O module with
process data.
PROFINET IO 750-340
LED Indication
Remedy
Turn off the supply voltage of the
node. Plug one I/O module with
process data behind the coupler
and observe the error argument
that is indicated after power on. If
no error argument is indicated by
the I/O LED, replace the
buscoupler. Otherwise identify the
faulty I/O module. Turn off the
power supply. Plug the end
module in the middle of the node.
Turn on the power supply again.
- If the LED keeps blinking, turn
off the power supply and plug the
end module in the middle of the
first half of the node (towards the
coupler).
If the LED does not blink, turn off
the power supply and plug the end
module in the middle of the second
half of the node (away from the
coupler).
Turn the power supply on again.
Repeat this procedure (while
halving the step size) until the
faulty I/O module is detected.
Replace the faulty I/O module.
If there is only one I/O module left
and the LED blinks, then either
this module or the coupler is
defective. Replace the faulty
component.
Turn off the supply voltage of the
node, replace the (n+1)th I/O
module with process data and turn
on the supply voltage again.
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