eTower Installation Manual Revision 0
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Fig 5.1 Pin Configuration for standard RJ45 plug
6.3
CAN Bus Control – Detailed Description
CAN is a widely used communication protocol in systems with many devices that must
report their status or send commands to other devices on the same network. The eTower
BMS can transmit messages and commands in CAN protocol to provide information to, but
more importantly to control, external devices. CAN allows great versatility and provides a
simple installation because there are only two wires required in this form of
communication, namely CAN High and CAN Low. In order for an inverter or charge
controller to be controlled by CAN it must first of all be equipped with a CAN interface as
well as a suitable method of connecting the CAN wires. Further to this the eTower BMS
must be programmed with a CAN messaging profile that is developed for the inverter or
charge controller being used. This profile must be specifically developed for each inverter
model or model range. To date Freedom Won has developed CAN profiles for a wide range
of inverters – see the Freedom Won Inverter Interfacing Guide for more information.
Freedom Won welcomes any requests to produce BMS CAN profiles for other inverters that
are CAN equipped for BMS interface.
The CAN interface can provide the following functionality to compatible devices:
i.
Charge Current Limit of all Lite’s connected
ii.
Discharge Current Limit of all Lite’s connected
iii.
Actual State of Charge (minimum of all lights connected)
iv.
Actual Battery Temperature (highest of all lights connected)
v.
Actual Voltage
vi.
Actual Current (total of all Lite’s connected)
vii.
Maximum real time charge voltage setpoint
viii.
Battery Name
ix.
Highest Cell Voltage of all Lite’s connected
x.
Lowest Cell Voltage of all Lite’s connected.
xi.
Firmware Version
xii.
Ah capacity of all batteries connected
