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3.2 Inputs and outputs

Version 3.7 by Admin on 2025/01/28 14:43

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Inputs and outputs

Discrete inputs

The BMS Mini device has 4 discrete inputs of the "dry contact" type. For each discrete input, its assignment and inversion flag are set.

Assignments of discrete inputs are configured in the "Signals → Input discrete signals → Assignments" section:

1733743676787-110.png

The device supports the following discrete inputs assignments:

  • No input – input is not used;
  • Battery cover – a signal from the battery cover;
  • Charger connected – a signal indicating that charger is connected;
  • Power up/down request – a request to power down the device;
  • Inhibit charging – a command to open the charging contactor;
  • Inhibit discharging – a command to open the discharging contactor;
  • Insulation status – a signal from an insulation monitoring device;
  • Charge request – a request to close the charging contactor;
  • Precharge request – a request to close the precharging contactor;
  • Discharge request – a request to close the discharging contactor.

Inversion flags for discrete inputs are configured in the "Signals → Input discrete signals → Inversion" section:

1733743676791-123.png

Current sensor

The BMS Mini device has an ability to measure battery current by an external Hall-Effect current sensor.

Current sensor settings are configured in the "Signals → Current sensor" section:

1733743676792-692.png

The device supports the following current sensor settings:

  • Nominal current – rated current of the sensor according to the datasheet, А;
  • Sensitivity – sensitivity of the current sensor according to the datasheet, V / Inominal.;
  • Invert – invert the sign of the sensor value;
  • Calibrate – a flag to calibrate the current sensor when the device is started;
  • Calibration time – calibration time of the current sensor, millisecond;
  • Recalibrate current sensor – a command to calibrate the current sensor manually;
  • Multiply charging current (experimental) – an experimental flag for scaling the charging current by given multiplier;
  • Multiplier for charging current – charging current multiplier;
  • Auxiliary line – additional analog line:
    • Not connected;
    • Current sensor reference line;
    • AUX current sensor signal (in series) - a second output of a dual-range sensor (DHAB series) is connected to the auxiliary line;
    • AUX current sensor signal (parallel) - a second current sensor is connected to the auxiliary line, installed parallel to the main one;
  • Nominal current (AUX) – rated current of the auxiliary sensor according to the datasheet, А;
  • Sensitivity (AUX) – sensitivity of the auxiliary current sensor according to the datasheet, V / Inominal.;
  • Threshold (AUX) – a threshold current value at which the device uses the readings of the main current sensor (the "AUX current sensor signal (in series)" mode is activated);
  • Invert (AUX) – invert the sign of auxiliary current sensor value;
  • Multiply AUX charging current (experimental) – an experimental flag for scaling the auxiliary charging current by given multiplier;
  • Multiplier for AUX charging current – auxiliary charging current multiplier.

Shunt sensor (CAN bus)

The BMS Mini device has an ability to measure battery current via shunt sensor, connected to CAN bus.

Shunt sensor settings are configured in the "Signals → Shunt sensor (CAN bus)" section:

1733743676793-251.png

The device supports the following shunt sensor settings:

  • Enable – a flag to start interaction with the BMS Current Sensor (if interaction is enabled then BMS doesn’t use Hall-Effect current sensor which settings are described in the section "Signals → Current sensor");
  • Node ID – an address of BMS Current Sensor in CANopen network;
  • Invert – a flag to invert current values;
  • Receive timeout – a timeout for receiving messages from BMS Current Sensor (if no data is being received from the current sensor during this time, the “Shunt offline” flag is set), millisecond;
  • Mean value threshold – TM level, A (if module of instantaneous current (II) which is received from the shunt sensor is between TM and T0, the BMS will use mean value of current IM; if II is greater than TM, the BMS will use instantaneous value of current II);
  • Zero threshold – T0 level, A (if module of instantaneous current (II) which is received from the shunt sensor is lower than T0, the BMS will assume that current flowing through the battery is zero);

Temperature sensor

Temperature sensors settings are configured in the "Signals → Temperature sensors" section:

1733743676794-795.png

In this section:

  • Type – a type of temperature sensors.

Output discrete signals

The BMS Mini device has four +5V digital outputs. For each discrete output, its assignment and inversion flag are set.

Assignments of discrete outputs are configured in the "Signals → Output discrete signals → Assignments" section:

1733743676795-962.png

The device supports the following digital output assignments:

  • No output – output is not used.
  • Cooler – a command to turn on a cooler;
  • Heater – a command to turn on a heater;
  • Allow charging – a signal for a charger to start charging;
  • Precharging – a signal to charge the capacitive load;
  • Power down ACK – an acknowledgement of BMS power down. Acknowledgement is outputted when the charge and discharge contactors have been opened on power down request;
  • Power up – an indication of BMS power status.

Inversion flags for discrete outputs are configured in the "Signals → Output discrete signals → Inversion" section:

1733743676796-673.png

MOSFETs

The BMS Mini device has four MOSFET switches to drive contactors. For each switch, its assignment and inversion flag are set.

Assignments of MOSFETs are configured in the "Signals → MOSFETs → Assignments" section:

1733743676797-285.png

The device supports the following switch assignments:

  • No output – switch is not used;
  • Charging – charging contactor;
  • Discharging – discharging contactor;
  • Heater – heater contactor;
  • Allow charging – a signal for a charger to start charging;
  • Precharging – precharge contactor;
  • Cooler – cooler contactor;
  • Discharging (AUX) – auxiliary discharging contactor;
  • Main contactor – main contactor;
  • Charging/Discharging – charging/discharging contactor;
  • Power up – power up contactor.

Inversion flags for switches are configured in the “Signals → MOSFETs → Inversion” section:

1733743676798-103.png

Feedback flags for contactors are configured in the “Signals → MOSFETs → Contactors feedback” section:

1733743676799-349.png

Wire resistance compensation

Warning!
This section applies only to BMS Mini S v1.0 and BMS Mini v2.0 (devices without X9 header).

The BMS Mini is powered directly from the battery. This causes the voltages of th fisrt and the last cells to be measured with an error, the magnitude of which is proportional to the current drawn by the BMS and the resistance of the wires connecting these cells to the BMS. To compensate for the cell voltage measurement error, the BMS Mini provides a wire resistance setting.

Setting the resistance of the wires connecting the first and last cells of the battery with the BMS is performed in the “Signals → Wire resistance compensation” section:

1733743676800-295.png

In this section:

  • Wire resistance (Cell 0) – resistance of the wire connecting the “minus” of the first cell with the BMS Mini’s “ground”;
  • Wire resistance (Cell X) – resistance of the wire connecting the “plus” of the last cell with the BMS Mini power supply “plus”.