Jsy Mk 354 Modbus Register 286: Active Energy L3
Technical documentation for Modbus register 286 on Jsy Mk 354. Data type: U DWORD. Includes Python and YAML configuration examples.
January 16, 2026
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1 min read
Technical Definition
The register Active Energy L3 at address 286 is used to monitor active energy l3 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 Active Energy L3 (Address: 286)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=286, 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: "Active Energy L3"
address: 286
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: Active Energy L3 (kWh): Accumulated real power consumed on phase L3. Measures work done.
Troubleshooting: Zero/low value indicates no consumption or a fault in the meter/wiring for L3. Verify load operation.