Modbus Client Xemex Modbus Register 20496: RMS Current CT3

Technical Definition

The register RMS Current CT3 at address 20496 is used to monitor rms current ct3 on the Modbus Client Xemex.

• Protocol: Modbus RTU
• Data Type: FP32
• Unit: A
• 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 RMS Current CT3 (Address: 20496)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=20496, 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: "RMS Current CT3"
  address: 20496
  value_type: FP32
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Modbus Client Xemex]

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

💡 Engineer's Insight

Analysis: Root Mean Square (RMS) current measurement for Current Transformer 3 (CT3). Units: Amperes (A).

Troubleshooting: Zero value indicates no current flow, a faulty CT, incorrect wiring, or a configuration issue.