Modbus Registers

These registers are available for Modbus RTU and Modbus TCP. The cFos Power Brain Controller supports the Modbus functions

03 read multiple holding registers
06 write single holding register
16 write multiple holding registers

We distinguish four devices:
2 S0 meters, 1 charging station and 1 attached (Modbus) meter, which are distinguished by the Modbus slave ID and (for Modbus TCP) the TCP port.

Note: Write access to the Modbus registers causes writing to the flash memory of the cFos Power Brain and should therefore not take place regularly. The following registers are not saved permanently and can therefore be changed regularly: charging_cur_limit, fixed_current, charging_enable, disconnect_cp, relay_select, relay2. All other registers are written to flash when they are changed, so the number of write operations should be limited!

Default Slave IDs

EVSE	Slave Id 1	TCP port 4701
S0 Meter 1	Slave Id 2	TCP port 4702
S0 Meter 2	Slave Id 3	TCP port 4703
pinned counter	Slave Id 1	TCP port 4701 (via Wallbox Register)

Depending on which device it is and whether, for example, a meter is attached to the EVSE, the following registers apply:

Registers (r = read-only, w = write-only, rw = read/write)

Registers for S0 Meters and the EVSE

Name	Address	Registers	Description
vendor_id	8000	2 r	Unique vendor id, 0xcf05
product_id	8002	1 r	Product id, 1
device_id	8003	1 r	Device id inside the product, 0x100
product_version	8004	2 r	Product version, major.minor
product_build	8005	1 r	Product build number
mapping_version	8006	1 r	major.minor version of this register mapping
padding_1	8007	1 r	Reserved
serial_no	8008	8 r	Serial number string
name	8016	16 r	Product name, "cFos Power Brain Controller"
slave_id	8040	1 rw	Modbus slave ID

Registers for S0 Meters

Name	Address	Registers	Description
input	8041	1 r	Reserved
pulsesperkwh	8042	2 rw	Impulses per kWh for input S0
phases	8044	1 rw	Bitmask of simulated phases, bit 0 = L1, bit 1 = L2, bit 2 = L3
voltage_l1	8045	1 rw	Nominal Voltage L1 [V]
voltage_l2	8046	1 rw	Nominal Voltage L2 [V]
voltage_l3	8047	1 rw	Nominal Voltage L3 [V]
pulses	8050	4 rw	Absolute number of pulses on S0 input
timeperpulse	8054	2 r	Time between last two pulses on S0 input [ms]
level	8056	1 r	Current input level of S0 input 0 = current flows, 1 = current does not flow
meter_flags	8057	1 r	bit 0: 1=has individual phases
energy	8058	4 rw	Active import [Wh]
power	8062	2 r	Active power [W]
current_l1	8064	2 r	Present current L1 [0.1 A]
current_l2	8066	2 r	Present current L2 [0.1 A]
current_l3	8068	2 r	Present current L3 [0.1 A]
reset_pulses	8070	1 w	Reset pulse counter [1]
reset_energy	8071	1 w	Reset energy [1]

Register for pinned counters

Registers 8057 to 8068 are available (see S0 counter)

Registers for the EVSE

Default values after reboot:

Name	Address	Registers	Description
def_fixed_current	8080	1 rw	Default value cable_current [0.1 A] ^(*)
def_charg_cur_limit	8081	1 rw	Default charging current limit [0.1 A] 6-63 ^(*)
def_charging_enable	8082	1 rw	Default charging enabled [0/1] ^(*)
^(*) This value will be set accordingly after a reboot.
fail_safe_duration	8083	2 rw	Number of seconds without reading/writing before charging_cur_limit and charging_enable are restored. Default value is 300 (5 minutes)
fail_safe_current	8085	1 rw	Power during inactivity, 0 = disable charging
disconnect_cp	8086	1 rw	Write: Number of seconds of switch-off CP, Read: Seconds remaining
relay_select	8087	1 rw	Write: 0=3-phase contactor, 1=1-phase contactor, for wallboxes that support this (at least controller Rev. F)
relay2	8088	1 rw	Write: 0=relay 2 off, 1=relay 2 on (only if relay 1 is off), for wallboxes that support this (at least controller Rev. F)
cable_current	8090	1 r	PP: Cable max current [0.1 A], 0: no cable
fixed_current	8091	1 rw	Overwrite cable_current [0.1 A]
charge_pilot_state	8092	1 r	CP: 0 = A (waiting), 1 = B (vehicle detected), 2 = C (charging), 3 = D (charging with ventilation), 4 = E (no power), 5 = F (error)
charging_cur_limit	8093	1 rw	Charging current limit [0.1 A] 6-63A, may be limited due to model limitations (e.g. for cFos Power Brain Wallbox 11kW, it's limited to 16A)
charging_enable	8094	1 rw	Charging enabled [0/1] 0 = disable, 1 = enable
charging_current	8095	1 r	Charging current [0.1 A] 6-63
last_rfid	8096	15 r	Last seen rfid (hex-string)
detected_rfids	8111	1 r	Number of RFID inputs
has_meter	8112	1 r	1, if a counter is attached (then registers 8057-8068 are readable), otherwise 0
s0_inputs	8113	1 r	Bit 0=State S0 input 1, bit 1=State S0 input 2
count_restart	8120	2 rw	Number of restarts of the hardware

Documentation