20
Causes
Malfunctions occur if CAN bus components have been mounted or configured incorrectly or if elec-
tronic component parts are defective, or in the event of excessive heat in the equipment or electrical
interference in the supply system.
Further malfunctions are:
n
Faulty communication in CAN bus system
n
24 V PSU in control unit overloaded.
System Malfunctions
Note
Before carrying out the systematic fault finding procedure please check:
Wiring:
Is the wiring in accordance with the wiring diagrams?
Is the polarity correct throughout the whole bus line?
Is the bus line of each of the end nodes provided with a 120 Ω terminating resistor?
Configuration of temperature transmitter TRV 5-40
Is the transmitter correctly adjusted as device 1, 2, 3 or 4?
Node ID:
Are the node IDs set correctly?
Do not use a node ID twice!
Baud rate:
Is the cable length appropriate for the baud rate?
Is the baud rate setting identical for all devices?
Danger
The terminal strips of the control unit TRS 5-40 are live during operation.
This presents the risk of severe cases of electric shock!
Always
cut off power supply
before mounting, removing or connecting the terminal
strips!
An alarm is raised if the CAN bus is interrupted during operation.
