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Esp32 Jk Pb Modbus Example Modbus Register 4644: Name cell voltage 19

Technical documentation for Modbus register 4644 on Esp32 Jk Pb Modbus Example. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register name cell voltage 19 at address 4644 is used to monitor name cell voltage 19 on the Esp32 Jk Pb Modbus Example.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • Unit: V
  • Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read name cell voltage 19 (Address: 4644)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4644, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "name cell voltage 19"
  address: 4644
  value_type: U_WORD
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Jk Pb Modbus Example]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device


💡 Engineer's Insight

Analysis: Voltage of cell 19 in Volts (V). Key indicator for overall battery pack integrity.

Troubleshooting: A zero reading implies a severe problem with cell 19, such as complete failure or a disconnect.