MultiMon MM8 - How to Wire Up and Configure the CANbus Network

MultiMon MM8 - How to Wire Up and Configure the CANbus Network

MultiMon MM8 uses CANbus to communicate to the WatchMonPlus (WM5) Supervisor.  

CANbus is a twisted pair wiring used to connect the devices wired from the WatchMonPlus (WM5) to the first MM8, then onto the second MM8  and so on, to form a chain.  

The last MM8 in the chain requires a 120 Ohm resister between CAN high and CAN low to indicate one end of the chain.  The other end of the chain could be the WatchMonPlus (WM5)  if there is no CAN link to an Inverter / Charger present or the Inverter / Charger itself.   

If using an Inverter / Charger, this is normally inbuilt into the device.  Where the WatchMonPlus (WM5) is one end of the chain it too requires a 120 Ohm resister between CAN high and CAN low. It is common to adopt the typical CAT5 or CAT6 Ethernet network cable and adopt 1 pair.

Uniquely identifying the devices for CANbus

The Hardware - Cellmon page and Hardware - Integration page need to be setup to 

Hardware Setup - CellMon Screen

The following should be configured within the Master Supervisor (i.e. WM5) as follows: 

- Has Satellite:           On        Enabled to specify the entire range of satellites

- First Cell ID:               1         Typically the lowest cell voltage in series

- Last Cell ID:              14         Number of cells in series monitored by the local supervisor

-  Entire Range First      1         Identical to the first cell 

- Entire Range Last:    28        Last number in the entire range of cells, typically the total number of                                                          cell monitored 

- Dif Nominal               On       Enable for multiple parallel strings, but off for high voltage systems in                                                        series 

- Nominal Series         14        Outline the typical number when more than one parallel string

On the MultiMon MM8 should be configured as follows: 

- Has Satellite:    Off 

- First Cell ID:      15      next number in sequence (i.e. if after the WM5 supervisor which has 1-14,                                             it would be 15) 

- Last Cell ID:      28       incremental number above the first ID for the number of cells monitored (i.e.                                               if first is 15 for 14 cells will be 28)

- Entire Range First    N/A      Calculated 

- Entire Range Last:    N/A      Calculated 

- Dif Nominal              Off

- Nominal Series         N/A      Calculated

Hardware Setup - Integration Screens

On the Master Supervisor (i.e. WM5) the following should be configured: 

- protocol : Project Coconut for solar inverters (or Native2 for EV projects) 

- base address is 0x500 , if multiple BMS supervisors exist on the same canbus network, the addresses must be different and not overlap

- group address is 0x520 this is the same for all devices that are part of the same BMS so that both the master and satellites can see each other 

- remote address is  0x0 and only relevant to communicate with a specific charger if a function of that canbus profile

The MultiMon MM8 should be configured as follows: 

- protocol :    MultiMon Satellite (or Reserved 37 for faster updates) 

- base address is 0x540 . If there are multiple each needs to be different (typically in increasing ranges of 0x20) and must not overlap (0x560, 0x580, etc). 

- group address is 0x520 this is the same for all devices that are part of the same BMS supervisor

- remote address is  0x0  not relevant for satellites