cFos · EV charger
Power Brain Controller / Wallbox Modbus register map
Default configuration
- Protocol
- Modbus TCP
- Port
- 4701
- Unit ID
- 1
- Addressing
- 0-based
- Byte order
- Big endian
- Word order
- High word first
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 8040 | 1 | Modbus slave ID Slave ID the controller answers on, factory default 1. | UInt16 | - | 1 | RW |
| 8057 | 1 | Meter flags Bit 0 = the attached counter has individual phases. | UInt16 | - | 1 | R |
| 8062 | 2 | Active power Active power of the attached counter. | UInt32 | W | 1 | R |
| 8064 | 2 | Current L1 | UInt32 | A | 0.1 | R |
| 8066 | 2 | Current L2 | UInt32 | A | 0.1 | R |
| 8068 | 2 | Current L3 | UInt32 | A | 0.1 | R |
| 8080 | 1 | Default fixed current Value the cable current returns to after a restart. | UInt16 | A | 0.1 | RW |
| 8081 | 1 | Default charging current limit Value the charging current limit returns to after a restart; 6-63 A. | UInt16 | A | 0.1 | RW |
| 8082 | 1 | Default charging enabled 0 = charging disabled, 1 = charging enabled after a restart. | UInt16 | - | 1 | RW |
| 8083 | 2 | Failsafe duration Seconds without a Modbus read or write before the failsafe current is applied; 0 deactivates, default 300. | UInt32 | s | 1 | RW |
| 8085 | 1 | Failsafe current Current applied during inactivity; 0 disables charging. | UInt16 | A | 0.1 | RW |
| 8086 | 1 | Disconnect CP Write: seconds until the control pilot is switched off. Read: seconds remaining. | UInt16 | s | 1 | RW |
| 8087 | 1 | Relay select 0 = 3-phase contactor, 1 = 1-phase contactor, for wallboxes that support phase switching (controller revision F or newer). | UInt16 | - | 1 | RW |
| 8088 | 1 | Relay 2 0 = relay 2 off, 1 = relay 2 on (only while relay 1 is off), for wallboxes that support it. | UInt16 | - | 1 | RW |
| 8090 | 1 | Cable current Maximum cable current from the control pilot proximity pin; 0 = no cable. | UInt16 | A | 0.1 | R |
| 8091 | 1 | Fixed current Overrides the cable current from the proximity pin. | UInt16 | A | 0.1 | RW |
| 8092 | 1 | Charge pilot state 0 = A (waiting), 1 = B (vehicle detected), 2 = C (charging), 3 = D (charging with ventilation), 4 = E (no current), 5 = F (error), 9 = DC sensor error; other values are errors. | UInt16 | - | 1 | R |
| 8093 | 1 | Charging current limit Charging current limit, 6-63 A; may be capped by the model (a Power Brain 11 kW stops at 16 A). | UInt16 | A | 0.1 | RW |
| 8094 | 1 | Charging enabled 0 = charging disabled, 1 = charging enabled. | UInt16 | - | 1 | RW |
| 8095 | 1 | Charging current measured | UInt16 | A | 0.1 | R |
| 8096 | 15 | Last RFID Hex string of the last RFID card that was read. | Ascii | - | 1 | R |
| 8111 | 1 | Detected RFID inputs | UInt16 | - | 1 | R |
| 8112 | 1 | Has meter 1 when a counter is attached, so that 8057-8068 deliver values. | UInt16 | - | 1 | R |
| 8113 | 1 | S0 inputs Bit 0 = S0 input 1 state, bit 1 = S0 input 2 state, bit 8 = switching between 1 and 3 phases is permitted while plugged in, bit 9 = bit 10 is valid, bit 10 = second relay present, bit 11 = relay 2 is controlled externally (8088). | UInt16 | - | 1 | R |
| 8120 | 2 | Restart counter | UInt32 | - | 1 | RW |
| 8122 | 1 | Controller temperature Only for the cFos Power Brain Controller and the Wallbox Booster, controller revision 3.0 and newer. | UInt16 | °C | 1 | R |
Notes
Source: cFos eMobility, "Modbus Registers" for the cFos Power Brain Controller (https://www.cfos-emobility.de/en/cfos-power-brain/modbus-registers.htm and the PDF "cFos-Modbus", revision of 2024). The controller is the Modbus server on TCP port 4701 (not 502) with slave ID 1, and supports function codes 03, 06 and 16 on holding registers. A second S0 meter answers on slave ID 2 / TCP port 4702 and a third on 3 / 4703, so those registers are not part of this map. The 64-bit import-energy counter at 8058 (four registers) and the 64-bit pulse counter at 8050 are omitted because the app has no 64-bit integer data type; power and the per-phase currents give the same information in 32-bit form. The register summary in the German PDF and the English web page differ in the layout of the identification block (8000-8040), so only the slave ID register, which both render identically, is listed from that block. Writing registers other than charging_cur_limit/fixed_current/charging_enable/disconnect_cp/relay_select/relay2 is stored to flash, so keep write cycles low.