112 Diagnostics
WAGO-I/O-SYSTEM 750
753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
Manual
Version 1.0.0, valid from HW/SW Version 01/01
9.3.1
Channel Errors
In case of channel error, the corresponding bit in the channel status byte is set to
the value “bad” (0). Depending on the set analog value data format (see Section
“Functions” > “Analog Value Data Format”), the specific substitute value or
parameterized substitute value for the faulty passivated input channel in the
process image is transferred to the safe PLC.
The channel status LED of the respective input channel and group error LED
illuminate continuously in red. A diagnostic message corresponding to the error is
reported (see Section “Error Diagnostics”).
With two-channel pre-evaluation, the channel status of the second channel is
also set to the value “bad” (0).
Note the process image and channel status for module-wide passivation!
When passivation is module-wide, all channel status bits in the channel status
byte are set to “bad” (0). The substitute values are also transmitted to the safe
PLC for the error-free input channels.
Note the behavior of consecutive channel errors!
If another channel error is added in the same input channel after a channel error
without acknowledging the first channel error in the meantime, the first channel
error is kept. In such case, the diagnostics and safe substitute value of the first
channel error continue to be displayed!