6. Connectors Pinout¶
This section describes the pinout of all connectors on the foxBMS Master Unit.
6.1. Overview of the Connectors on the foxBMS Master Unit¶
foxBMS uses only Molex Micro-Fit 3.0 type connectors, except for USB. A comprehensive set of connectors and crimps is supplied with foxBMS to start connecting immediately. In case crimps or housings are missing, they are commonly available at major distributors.
Molex Micro-Fit 3.0 Crimps Part Number: 46235-0001 (Farnell 2284551)
Molex Micro-Fit 3.0 Connectors:
|Pin Count||Molex Housing Part Number||Farnell Order Number|
6.2. Supply (X201 on BMS-Master Board)¶
|1||SUPPLY_EXT2||Input||12 - 24V|
|2||SUPPLY_EXT2||Input||12 - 24V|
|4||SUPPLY_EXT0||Input||12 - 24V|
GND_EXT0: Microcontroller supply and insulation monitoring devices supply
GND_EXT2: Contactor supply and interlock supply
6.3. CAN0 (X801 on BMS-Master Board)¶
Ground of CAN0 is shared with supply ground
GND_EXT0. CAN0 is isolated from the MCU0 via the isolated CAN transceiver TJA1052. The CAN transceiver may be put into standby mode by MCU0.
6.4. CAN1 (X801 on BMS-Extension Board)¶
CAN1 has to be supplied externally (
SUPPLY_EXT1) with 12 - 24V. CAN1 is isolated from the MCU0 via the isolated CAN transceiver TJA1052. The CAN transceiver may be put into standby mode by MCU0.
6.5. Insulation Monitor (Bender ISOMETER) (X701 on BMS-Master Board)¶
|1||BENDER_NEGATIVE_SUPPLY||Output||Supply to insulation monitoring device|
|2||SUPPLY_EXT0||Output||Supply to insulation monitoring device|
|3||BENDER_OK_EXT||Input||Status signal of insulation monitoring device|
|4||BENDER_PWM_EXT||Input||Insulation monitoring device diagnostic signal|
This interface is intended to be used with a Bender insulation monitoring device. Bender ISOMETER IR155-3203/-3204/-3210 are supported. The Bender ISOMETER is supplied and may be switched on or off (lowside) by the foxBMS Master Unit. By factory, the foxBMS Master Unit is configured to operate with the Bender ISOMETER IR155-3204/-3210. In order to operate with the Bender ISOMETER IR155-3203, Jumper R705 must be removed on BMS-Master Board. For more details, check the schematic of the BMS-Master Board in section Design Resources.
6.6. Contactors (X1201 - X1206 on BMS-Master Board and X1201 - X1203 on BMS-Extension Board)¶
|1||GND_EXT0||–||Contactor auxiliary contact|
|2||CONTACTOR_X_FEEDBACK_EXT||–||Contactor auxiliary contact|
|3||CONTACTOR_X_COIL_POS||Output||Positive contactor coil supply|
|4||CONTACTORS_COMMON_NEG||Output||Negative contactor coil supply|
All contactor connectors share one common ground. This common ground is switched lowside by the interlock circuit. Opening the interlock loop deactivates the contactor supply and opens all contactors. A contactor auxiliary contact may be read by connecting the auxiliary contact to the corresponding pins of the contactor connector.
Freewheeling diodes are not populated on the PCB, since some contactors like the Gigavac GX16 have built-in diodes and should not be used with additional external freewheeling diodes in parallel. If the used contactors do not have built-in freewheeling diodes, freewheeling diodes must be added to protect the contactor control circuitry. The load current is limited by the optically isolated power switch AQV25G2S (6A continuous load). Every contactor connector is fused with an onboard slow blow fuse type Schurter UMT-250 630mA (3403.0164.xx).
6.7. Interlock (X901 on BMS-Master Board)¶
The interlock circuit has a built-in current source, adjusted to 10mA constant current. In fault conditions, all contactors are opened by opening the interlock circuit. If the interlock circuit is externally opened, the contactor supply is deactivated immediately. This circuit has no effect on the foxBMS supply or communication interfaces.
6.8. Daisy Chain - Primary and Secondary (X1601 on BMS-Master Board)¶
|2||OUT+ (Secondary BMS-Slave Board)|
|3||OUT- (Secondary BMS-Slave Board)|
|6||OUT+ (Primary BMS-Slave Board)|
|7||OUT- (Primary BMS-Slave Board)|
|1||OUT+ (Secondary BMS-Slave Board forward)|
|3||OUT+ (Secondary BMS-Slave Board reverse)|
|6||OUT+ (Primary BMS-Slave Board forward)|
|8||OUT+ (Primary BMS-Slave Board reverse)|
|9||OUT- (Secondary BMS-Slave Board forward)|
|11||OUT- (Secondary BMS-Slave Board forward)|
|14||OUT- (Primary BMS-Slave Board forward)|
|16||OUT- (Primary BMS-Slave Board reverse)|
Please note that this connector pin out is only valid when the BMS-Interface Board uses the LTC6820 interfacing IC.
6.9. RS485 (X1301 on BMS-Extension Board)¶
The RS485 interface uses the ESD rugged transceiver LT1785. Moreover, the interface is galvanically isolated. An external supply has to be provided (12 - 24V).
6.10. Isolated GPIO (X1901 on BMS-Extension Board)¶
The BMS-Extension Board provides 4 isolated general purpose inputs and 4 isolated general purpose outputs. The GPIOs are isolated by an ADUM3402 (i.e., ESD rugged version of the ADUM1402). The inputs are equipped with 10kOhm pull down resistors and are intended for a maximum input voltage of 5V. The output voltage is also 5V. An external supply is not needed.
6.11. Isolated Normally Open Contacts - isoNOC (X2001 on BMS-Extension Board)¶
The BMS-Extension Board features 6 isolated normally open contacts. The load current of each channel is limited by the optically isolated power switch AQV25G2S. The channels are not fused, however freewheeling diodes type GF1B are installed on board.
6.12. Analog Inputs (X1701 on BMS-Master Board)¶
On the BMS-Extension Board 4 nonisolated analog inputs to MCU0 are available. For applications using NTCs as temperature sensors, also a reference voltage of 2.5V is provided. The maximum input voltage is limited to 3.3V and is Zener protected. For further information on the input circuit, please refer to the foxBMS Master-Unit and to the foxBMS Design Resources.