Pack Modbus Register 28: Friendly name pack Cell Voltage 14

Technical Definition

The register friendly name pack Cell Voltage 14 at address 28 is used to monitor friendly name pack cell voltage 14 on the Pack.

• 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 friendly_name pack Cell Voltage 14 (Address: 28)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=28, 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: "friendly_name pack Cell Voltage 14"
  address: 28
  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[Pack]

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

💡 Engineer's Insight

Analysis: Voltage of Cell 14 within the battery pack, typically measured in Volts (V). Supports overall pack health assessment and charge management.

Troubleshooting: Check for: cell damage, loose terminal, wiring fault, or a malfunctioning measurement component.