34
System Malfunctions
– continued –
Danger
The terminal strip of the equipment is live during operation.
This presents the danger of electric shock.
Cut off power supply before mounting or removing the terminal strips or the housing cover.
The sources of malfunctions occurring in CAN bus systems operating with several busbased stations
must be analysed systematically since faulty components or incorrect settings can give rise to
nega tive interactions with intact bus devices in the CAN bus system. These unwanted interactions
can cause error messages in fully functional bus devices, which will make fault detection even more
difficult.
We recommend the following systematic fault finding procedure:
Systematic malfunction analysis
Step 1 (Start)
Detach terminal strips
in all sensing units of
bus devices.
Level electrode
Conductivity electrode
Pressure sensor
Temperature sensor etc.
Step 3
Apply mains voltage
to bus devices
of the system, e. g.
NRS...
and
NRG...
Step 2
Plug in terminal strip
of the sensing unit
of one system, e. g.
NRS...
and
NRG... (sensor)
.
System O.K.
Detach terminal strips
between bus devices
of the system, e. g.
NRS...
and
NRG...
System
Malfunction
Use faultfinding list
to identify the fault(s).
Cut off power supply
to the equipment.
Check
Use faultfinding
list to correct
fault(s)!
Final test:
have all faults
been eliminated?
Check next system
