Issue
Re-addressing I/A Series BACnet controllers on an existing BACnet MS/TP installation
Environment
I/A Series R2 BACnet integration to I/A Series Micronet BACnet Controllers
Cause
There are gaps in BACnet MS/TP addressing which needs to be fixed. Gaps in addressing add delays in communications. Addressing should begin with node 0 (zero) and progress through all nodes, without any gaps, for each separate MS/TP
network.
Refer to the I/A Series MicroNet BACnet Wiring, Networking, and Best Practices Guide (F-27360-7).
Resolution
The procedure to change the addresses of the MNB controllers involves the following steps.
- Changing the physical DIP switch address on the MNB controllers.
- Making sure the MAC Address of the BACnet shadow device object in the I/A Series R2 UNC reflects the change.
- Changing the Max Master property in each MNB controller using WorkPlace Pro. Alternatively, you can change the Max Master property using the WorkPlace Commissioning Tool.
1. Changing the physical DIP switch address on the MNB controllers
- Have a piece of paper ready to note down the physical DIP switch address before and after the change.
- DIP switch addressing should be sequential starting from ‘0’ with no gaps in between. However, the physical location of the device does not matter. For example, if we have 30 MNB controllers on the BACnet MS/TP network, the addresses should be from 0 to 29 but they do not have to be in order physically. As an example, the first MS/TP device could have an address of '0' while the second MS/TP device on the wire can have an address of '10'. The MNB-1000 should be address ‘0’ if it is the first MS/TP device. If the first MS/TP device is an UNC, the UNC should be address '0' (set in WorkPlace Pro).
- Use Table–2.3 to calculate the DIP switch value for physical addressing. Take, for example, that the address must be set to 16. To do so, you would set switch number 5 (value=16) to ON. If the address is to be set to 43, instead, you would set switches 1, 2, 4, and 6 to ON (value=1+2+8+32=43).
- The controller should reset itself about 10 seconds after the change and the new address will be in effect.
2. Check / change the MAC Address of the BACnet shadow device object in the UNC using WorkPlace Pro.
- After changing the physical DIP switch of the device, we will need to make sure that they change has been reflected in the corresponding BACnet shadow object device in the UNC.
- Using WorkPlace Pro, open the UNC station.
- Go to the Properties of the MNB shadow device object and go to the ‘Config’ tab.
- Make sure that the 'MAC Address' field is showing the new address (in HEX) of the controller.
3. Changing the Max Master property in each MNB controller using WorkPlace Pro.
- Each MNB controller under a particular BACnet MS/TP trunk needs to have their ‘Max Master’ setting changed. Set ‘Max Master’ to 1 or 2 higher than the highest address on the MS/TP network. If the highest addressed device is DIP switch value 50, set the Max Master to 51 or 52.
- In WorkPlace Pro, open the UNC station.
- Go to the Properties of the MNB shadow device object and go to the ‘Engineering’ tab.
- Change the ‘maxMaster’ to a value that is 2 higher than the highest addresses device. Click ‘Apply’.
