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9. Fault finding
9.1 LED status
Faults in a CIM/CIU 300 can be detected by observing the status of the two communication LEDs. See the table below.
9.2 BACnet faults
Fault (LED status)
Possible cause
Remedy
1. Both LEDs (LED1 and LED2) remain
off when the power supply is
connected, and 5 seconds have
passed.
a) The CIM 300 is defective.
Replace the CIM 300.
2. The LED for internal
communication (LED2) is flashing
red.
a) No internal communication
between the CIM/CIU 300 and the
Grundfos booster.
• Check the cable connection between the booster
and the CIU 300.
• Check that the individual conductors have been
fitted correctly.
• Check the power supply to the booster.
3. The LED for internal
communication (LED2) is constantly
red.
a) The CIU 300 does not support the
connected booster.
Contact the nearest Grundfos company.
4. The BACnet LED (LED1) is
constantly red.
a) Fault in the CIM 300 BACnet
configuration.
• Ensure that the BACnet MAC address has a valid
setting.
See section
3.7 Selecting the BACnet MAC address
.
• Ensure that the Device Object Instance Number is
within the allowed range.
See section
3.5 Selecting the Device Object Instance
Number
.
5. The BACnet LED (LED1) is flashing
red.
a) Fault in the BACnet communication
(cyclic redundancy check).
• Check the transmission speed
(switches SW4 and SW5).
See section
3.4 Setting the BACnet transmission
speed
.
• Check the cable connection between the CIM 300
and the BACnet network.
• Check the termination resistor settings (switches
SW1 and SW2).
See section
3.8 Termination resistor
.
Fault
Possible cause
Remedy
1. The CIM/CIU 300 does not
communicate on the BACnet MS/TP
network.
a) Configuration or wiring fault.
Ensure that the cable between the BACnet MS/TP
devices is connected correctly.
See section
3.3 Connecting to the BACnet network
.
Ensure that the BACnet MAC address and Device Object
Instance Number are configured correctly and are
unique on the network.
See section
3.7 Selecting the BACnet MAC address
and
3.5 Selecting the Device Object Instance Number
for
address selection.
Ensure that the transmission speed is configured
correctly.
See section
3.4 Setting the BACnet transmission speed
.
Ensure that each end of the BACnet MS/TP
trunk cable is terminated, if necessary.
See section
3.8 Termination resistor
for line termination
of the Grundfos CIM/CIU 300.
Ensure that the bus topology for
a BACnet MS/TP network is correct.
b) The CIM/CIU 300 is instructed to
not communicate on the BACnet
network via the
DeviceCommunicationControl
service.
Use the Device Communication Control service to
enable communication from the device.
2. The booster does not react to
control commands from the bus.
a) The booster is running in local
mode.
• Set the booster to bus control by setting the
Present_Value of BO, 0 to 1.
• Set bus control on the CU 351display (settings/
secondary functions/control source, and select
"controlled from bus").
3. There are only a few BACnet
objects available, and the GENIbus
LED flashes red.
a) There is no communication
between the CIM 300 and the
booster.
Ensure that the GENIbus cable between the CIM 300
and the booster is connected correctly.
Ensure that the booster is switched on and able to
communicate on GENIbus.
