The following table lists the Modbus Holding Registers.

For each point, the “Multiplier” column indicates the value by which the register data are multiplied. Since all data are sent in integer format, floating point numbers are multiplied by a constant (1, 10, or 100) to maintain decimal information. For example, registers with two decimal places of resolution are multiplied by 100 (5.67 is sent as 567) while registers with one decimal place of resolution are multiplied by 10 (8.2 is sent as 82). To convert a register to the correct value, simply divide the register value by the “Multiplier” value.

When writing a value to a Holding Register, you must multiply the desired value by the constant in the “Multiplier’. For example, to change the “Float Voltage Set Point’ to 132 volts, you would need to write 1320 to Holding Register “40001’ (132 × 10 = 1320). The “10’ is the multiplier constant listed in “Multiplier’ column for Holding Register “40001’.

The “Valid Range’ column lists the possible values that can be successfully written to the associated Holding Register. This is the true value and does not include the multiplier correction. Attempting to write values outside of this range will result in a Modbus error returned as an Exception Response.

The valid range for many of these points depends on ATevo battery charger model (Vdc – Adc rating). To determine valid ranges of these set points, refer to user supplement (JA5124-02).

Modbus Holding Registers
Address Name/Description Multiplier (format) Valid Range
40001 Float Voltage Set Point (Vdc) 10 (XXX.X) see JA5124-02
40002 Equalize Voltage Set Point (Vdc) 10 (XXX.X) see JA5124-02
40003 Equalize Timer Set Point (hours) 1 (XX) 1 <= XX <= 99
40004 Current Limit Set Point (Adc) 10 (XXX.X) see JA5124-02
40005 High Voltage DC Alarm Set Point (Vdc) 10 (XXX.X) see JA5124-02
40006 Low Voltage DC Alarm Set Point (Vdc) 10 (XXX.X) see JA5124-02
40007 High Level Detect Set Point (Vdc) 10 (XXX.X) see JA5124-02
40008 Low Level Detect Set Point (Vdc) 10 (XXX.X) see JA5124-02
40009 End of Discharge Set Point (Vdc) 10 (XXX.X) see JA5124-02
40010 AC Ripple Alarm Set Point (mV) 1 (XXX) 50 < XXX < 250 (in 5mV steps)
40011 Positive Ground Fault Set Point (kOhms) 1 (XX) 10K <= XX <= 40K (in 1 kOhm steps)
40012 Negative Ground Fault Set Point (kOhms) 1 (XX) 10K <= XX <= 40K (in 1kOhm steps)
40013 Battery Type (chemistry) 1 (X) 0 – lead acid, 1 – NiCd
40014 Charger Mode Setting 1 (X) 0 – shutdown, 1 – battery open test, 2 – float, 3 – timed equalize
40015 Ground Fault Critical Setpoint (kOhms) 1 (XX) 1 <= X <= 50
40016 Vgnd Imbalance Warning Setpoint (Vdc) 1 (XX) see JA5124-02
40017 Vgnd Imbalance Critical Setpoint (Vdc) 1 (XX) see JA5124-02
40018 Battery Overtemp Setpoint (°C) 10 (XX.X) 30 <= XX <= 60
40019 Battery Open Test Frequency (days) 1 (XXX) 1 <= X <= 180
40020 Battery Open Test Duration (minutes) 1 (X) 1 <= X <= 8
40021 Battery Open Test Setpoint (Vdc) 1 (XXX) see JA5124-02
40022 Date/Time Low
(seconds since January 1, 2000)
1 (XXXXX) lower 16-bits
40023 Date/Time High
(seconds since January 1, 2000)
1 (XXXXX) upper 16-bits
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Last modified: 25 October 2023