referenced earlier. Note that the alarm will not be cleared if the alarm condition is still present.
Only BMS Faults are cleared using this point. BMS Warnings are not cleared.
Commanding the Nuvation Energy BMS stack/string to connect/disconnect is accomplished through
the
BSetOperation
point. This point accepts the enumerated values for these connect/disconnect
operations. Additional connection logic (such as separate pre-charge circuitry) is managed
automatically by the BMS when it is configured for such an operation.
7.1.4.2. External Nuvation Energy BMS Monitoring Over MESA Interface
An external data logger may want to access a variety of data from the BMS. In general, a data logger
will not actively manage Nuvation Energy BMS; normally, it will not initiate actions such as connecting
a battery stack to the DC voltage bus or clearing faults. A data logger should connect to one of the
read-only Modbus connections (if available) to allow the writable Modbus connection to be available
for separate external control functions. The following table contains the MESA data points exposed by
the BMS that could be collected for logging purposes.
Table 12. MESA Points Read by External Data Logger
Model
Block
Point Name
Address
Scale
Factor
Purpose
801
Fixed
SoC
40081
Yes
BMS State of Charge
801
Fixed
DERHb
40086
No
BMS Heartbeat counter incremented every second
802
Fixed
Evt1
40101
No
Bit field of all faults/warnings of a BMS
802
Fixed
Vol
40105
Yes
External DC voltage of the battery system
802
Fixed
MaxBatACha
40106
Yes
Charge current limit calculated by BMS
802
Fixed
MaxBatADischa
40107
Yes
Discharge current limit calculated by BMS
802
Fixed
BSetOperation
40110
No
BMS requested connection state of all stacks/strings
803
Fixed
BConStrCt
40118
No
Number of stacks/strings with contactor closed
803
Fixed
BMaxCellVol
40119
Yes
Maximum cell voltage measured
803
Fixed
BMaxCellVolLoc
40120
No
Module/String location of maximum cell voltage
803
Fixed
BMinCellVol
40121
Yes
Minimum cell voltage measured
803
Fixed
BMinCellVolLoc
40122
No
Module/String location of minimum cell voltage
803
Fixed
BMaxModTmp
40123
Yes
Maximum module temperature
803
Fixed
BMaxModTmpLoc
40124
No
Module/String location for maximum module
temperature
803
Fixed
BMinModTmp
40125
Yes
Minimum module temperature
803
Fixed
BMaxModTmpLoc
40126
No
Module/String location for minimum module
temperature
803
Fixed
BTotDCCur
40127
Yes
Total DC current of the battery system
803
Fixed
BMaxStrCur
40128
Yes
Largest DC current reported by a stack/string
803
Fixed
BMinStrCur
40129
Yes
Smallest DC current reported by a stack/string
803
Repeat
StrSoC
40135 +Index
No
State of charge for a stack/string
803
Repeat
StrSoH
40136 +Index
Yes
State of health for a stack/string
803
Repeat
StrCur
40137 +Index
Yes
Current of a stack/string
803
Repeat
StrMaxCellVol
40138 +Index
Yes
Maximum cell voltage of a stack/string
803
Repeat
StrMinCellVol
40139 +Index
Yes
Minimum cell voltage of a stack/string
Nuvation Energy High-Voltage BMS - Product Manual
Document ID: NE-PM-003
67
Rev 1.2, 2021-03-03
Curie Update 1