Diagnostics; Behavior In The Event Of An Error - WAGO -I/O-SYSTEM 750 Manual

110 Diagnostics

9 Diagnostics
9.1

Behavior in the Event of an Error

The F I/O module detects internal and external errors. Internal errors are
detected by continuous self testing. Depending on the configuration, external
errors are detected and diagnosed by testing the external circuits to the extent
possible. When detecting an external error, a diagnostic message is output to the
safe PLC. The diagnostic messages for external errors are described in the
section "Diagnostics" > ... > "Diagnosis of Errors".
In the event of an error, all digital inputs and power outputs of the F I/O module
are passivated by outputting the substitute values (failsafe values) instead of
actual process values. For the digital inputs, the substitute values "0" for the
process image are transferred to the safe PLC. The digital power outputs are
switched off.
The external errors can be eliminated by maintenance personnel and must then
be acknowledged by the operator triggering an acknowledgement (operator
acknowledgement).
Both internal and external errors can be evoked by strong EMC events. If an
internal error is diagnosed, the F I/O module switches off for safety. In this case,
acknowledgement by the operator remains ineffective.
To check whether the cause of an internal error was a temporary EMC event and
thus caused the safety-oriented shutdown, switching the entire fieldbus node off
and then on again can be performed in an attempt to activate the F I/O module
again.
If shutdowns occur frequently due to internal errors, the F I/O module should be
replaced.
In this case, return the defective F I/O module to WAGO Kontakttechnik GmbH &
Co. KG for fault analysis.
Manual
Version 1.4.2, valid from HW/SW Version 01/02
750-667/000-003 4FDI/4FDO 24V/2A PROFIsafe V2 iPar
WAGO-I/O-SYSTEM 750