In revision 49 of this document, Registers 2716 and 2717 were added as noted below:
Add register 2716 for frequent setpoint updates, to be used instead of 2700 or 2703
Add register 2717 to modify the ESS grid metering point
These are specified in the field list as:
|com.victronenergy.hub4|AC grid setpoint (volatile, in memory)|2716|int32|
|com.victronenergy.settings|Grid metering|2717|uint16|
However, a 32bit signed integer takes TWO modbus addresses, overwriting 2717 as well as 2716.
So 2717 should not be used for the Grid metering flag, as this will get corrupted by AC grid setpoint writes.
I would also like to question the use of different UID’s in this table. UID’s were used in RTU Modbus (serial coms) in order to differentiate between the same registers in different remote unis. In a single register map on a single server (the Cerbo) using different UID’s for accessing different parts of the same map is probably inappropriate particularly as the UID’s assigned seem to vary with installation. I’ve found several different UID’s documented for accessing the Hub4 or Multiplus registers 37 thru 41, none of which coincide with the UID allocated by my Cerbo when testing this.
Whilst enabling all the UID’s will be required for backwards compatibility, allowing access for UID 1 or 100 to the entire register set would make life a lot simpler. In a system with multiple Cerbos, the Modbus map of each Cerbo is differentiated by the IP address, so they can all use the same UID.