8
3.5.1 Default Instance Number
By default, the CIM 300 uses a pre-defined Device Object Instance
Number, which is 227XXX where XXX is the BACnet MAC address.
This gives an Instance Number range of 227000 to 227127.
See section
3.7 Selecting the BACnet MAC address
for more
information on MAC addresses.
Example:
The BACnet MAC address is set to 20 via the hexadecimal rotary
switches, so the Device Object Instance Number is 227020.
3.5.2 Custom Instance Number
To use the complete Instance Number range, set the new Instance
Number with the BACnet object Custom Device Object Instance
Number (AV, 0), and set SW3 to ON. This will immediately set the
new Device Object Instance Number.
See fig.
6
for DIP switch location.
Fig. 6
Device Object Instance Number
The default Present_Value of the Custom Device Object Instance
Number is 231.
Example:
The Present_Value of Custom Device Object Instance Number
(AV, 0) is 231, so the Device Object Instance Number is 231.
3.6 Selecting the Device Object Name
The property Device_Name is a character string that must be
unique inter-network-wide. By default, the name will be
constructed as "Grundfos - XXXXXX" where XXXXXX is the current
Device Object Instance Number as described in section
3.5 Selecting the Device Object Instance Number
.
Example:
The Device Object Instance Number is 227001, so the Device
Object Name is "Grundfos - 227001".
If a new name is selected, it will be stored in the device and
replace the default naming scheme.
3.7 Selecting the BACnet MAC address
To set the BACnet MAC address, use the two hexadecimal rotary
switches (SW6 and SW7).
The value must be within the range of 0 to 127. An illegal value will
result in a MAC address of 0.
Fig. 7
Setting the BACnet MAC address
For a complete overview of BACnet addresses, see section
12. BACnet MAC address
.
3.8 Termination resistor
A termination resistor for line termination is fitted on the CIM 300
and has a value of 120 Ω. It should be cut in if the CIM 300 is set as
the last station on the network.
The CIM 300 has two DIP switches (SW1 and SW2) for cutting the
termination resistor in and out. Figure
8
shows the DIP switches in
cut-out state.
Fig. 8
Cutting the termination resistor in and out
Default setting: Termination resistor cut-out.
3.9 Cable length
The maximum recommended cable length within a BACnet
MS/TP segment is 1200 metres (4000 ft) with 0.82 mm
2
(AWG 18)
cable.
The connection between the BACnet modules must be made by
use of a screened, twisted-pair cable with a characteristic
impedance between 100 and 130 Ω.
TM
04
1709
0908
Device Object Instance Number
SW3
Default ( BACnet MAC address)
OFF
Custom, set with object (AV, 0)
ON
Note
The Present_Value of Custom Device Object Instance
Number cannot be 4194303, as this is a reserved
value.
TM
04
1706
0908
Note
The BACnet MAC address must be set decimally from
0 to 127 and must be unique on the BACnet MS/TP
segment.
SW3
SW6
SW7
TM
04
1701
0908
Status
SW1
SW2
Cut-in
ON
ON
Cut-out
OFF
OFF
ON
OFF
OFF
ON
SW1 SW2
