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3.3 Input and output signals

Version 4.2 by Admin on 2024/11/21 15:14

3.3.1 Input signals

The BMS Main 2.x board has 4 digital inputs of the "dry contact" type. For each discrete input, its purpose and the inversion requirement are specified. The following discrete input assignment options are supported:

  • no signal;
  • signal from battery cover;
  • charger connected;
  • power up/down request;
  • inhibit charging;
  • inhibit discharging;
  • CH contactor feedback;
  • DCH contactor feedback;
  • Insulation status;
  • Charge request;
  • Precharge request;
  • Discharge request;
  • PCH contactor feedback;
  • CH/DCH contactor feedback;
  • Main contactor feedback.

If the "Signal from the battery cover" assignment is selected, the discrete input is used to monitor the state of the battery cover (see section Battery cover protection).

if the "Charger connected" assignment is selected, the discrete input is involved in the algorithms of charge and discharge control (see sections Charge control and Discharge control).

If the "Power up/down request" assignment is selected, the discrete input is involved in the algorithms of opening the charging and discharging relays and sending acknowledgment of power down to the external equipment (see sections Charge control and Discharge control).

If the “Inhibit charging” assignment is selected, the discrete input is used to open the charging relay.

If the “Inhibit discharging” assignment is selected, the discrete input is used to open the discharging relay.

If the “CH contactor feedback”, “DCH contactor feedback”, “PCH contactor feedback”, “CH/DCH contactor feedback” or “Main contactor feedback” assignment is selected, the discrete input is involved in monitoring the corresponding contactor’s feedback signal (see section Contactor feedback check).

If the “Charge request”, “Precharge request” or “Discharge request” assignment is selected, the discrete input is used to control opening the corresponding contactor (see sections Charge control and Discharge control).

If the “Insulation status” assignment is selected, the discrete input is used to monitor a signal from an external insulation monitoring device (see section Insulation monitoring).

BMS Main 2.x board has 4 analog inputs for connecting current, temperature and humidity sensors. Assignment of analog inputs must be selected as follows:

  • Analog Input #1– Current sensor;
  • Analog Input #2– No input / Current zero level (see note);
  • Analog Input #3 – No input / Temperature sensor / Current sensor (AUX) / Current zero level (AUX);
  • Analog Input #4 – No input / Humidity sensor / Current sensor (AUX) / Current zero level (AUX).

Important: the connection of an additional current sensor (AUX) is possible for special hardware revision of the BMS Main 2.x board. Using an additional current sensor is possible in the configuration when BMS Main serves two galvanically isolated cell series (see section Series balancing).

Warning: reassignment of analog inputs is unacceptable.

Note: The default setting for Analog input #2 is "No signal". If it is necessary to use a current sensor with an additional zero level signal, set the "Current zero level" assignment.

 To configure the input discrete and analog signals, select the menu "Signals → Input signals":

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Input signals section

The order of the numbering of the discrete and analog inputs corresponds to the order of the numbering on the board.

In this section:

  • Discrete inputs:
    • No input;
    • Battery cover – a signal from the battery cover trailer;
    • Charger connected – a signal from the charger connector;
    • Power up/down request – a signal from the external power monitor which is used for proper powering BMS up or down;
    • Inhibit charging – a command to open the charging relay;
    • Inhibit discharging – a command to open the discharging relay;
    • CH contactor feedback – a feedback signal from the charging contactor;
    • DCH contactor feedback – a feedback signal from the discharging contactor;
    • Insulation status – a signal from an external insulation monitoring device;
    • Charge request – a request for closing the charging contactor;
    • Precharge request – a request for closing the precharging contactor;
    • Discharge request – a request for closing the discharging contactor;
    • PCH contactor feedback – a feedback signal from the precharging contactor;
    • CH/DCH contactor feedback – a feedback signal from the charging/discharging contactor;
    • Main contactor feedback – a feedback signal from the main contactor.
  • Analog inputs:
    • No input;
    • Current sensor;
    • Current zero level;
    • Temperature sensor;
    • Humidity sensor;
    • Current sensor (AUX) – additional current sensor for measuring current in a series of cells;
    • Current zero level (AUX) – zero level bus for additional current sensor.

3.3.2

After selecting the assignment of the analog inputs, you need to configure the parameters of the sensors connected to the board.