Jsy Mk 354 Modbus Register 326: Forward Reactive Energy L2

Technical Definition

The register Forward Reactive Energy L2 at address 326 is used to monitor forward reactive energy l2 on the Jsy Mk 354.

• Protocol: Modbus RTU
• Data Type: U DWORD
• Unit: kWh
• 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 Forward Reactive Energy L2 (Address: 326)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=326, 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: "Forward Reactive Energy L2"
  address: 326
  value_type: U_DWORD
  unit_of_measurement: "kWh"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Jsy Mk 354]

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

💡 Engineer's Insight

Analysis: Measures forward reactive energy (kVARh) consumed by Phase L2. Related to inductive/capacitive loads on this phase.

Troubleshooting: Zero if purely resistive load or no reactive power demand on L2. Check load type and phase wiring.