New product, as shown in the photographs, complete with external antenna, power supply and original packaging. The device is a 4-noks ZR-BR-485-EM, identified on the label as “Bridge ZigBee into Modbus RS485”. It is a wireless communication bridge designed to connect Modbus/RTU devices with an RS485 interface to a ZigBee network, eliminating the wired serial connection between the remote device and the gateway.

⚙️ Main Specifications

• Brand: 4-noks
• Model: ZR-BR-485-EM
• Type: ZigBee → Modbus RS485 Bridge
• Protocol: Modbus/RTU
• Interface: RS485
• Wireless technology: ZigBee / IEEE 802.15.4
• Radio frequency: 2405–2480 MHz
• Nominal RF power: 1 mW / 0 dBm
• Antenna: external
• Power supply: 12–24 V AC/DC ±10%
• Declared consumption: approx. 100 mA
• Routing/repeater function
• Can operate as a parent device for battery-powered sensors from the 4-noks family
• Protection rating: IP55, subject to the manufacturer's specified wiring conditions

🔧 Main Functions

The ZR-BR-485-EM allows one or more Modbus devices equipped with an RS485 interface to be connected to a wireless ZigBee network.
The device converts the physical RS485 connection into a wireless ZigBee connection, allowing a 4-noks gateway to communicate with remote Modbus equipment without installing an RS485 cable all the way to the gateway. The Modbus channel is handled transparently.

🔌 Purpose and Operation

The bridge is installed near the Modbus device to be connected, such as:

• energy meters;
• power meters;
• controllers;
• I/O devices;
• industrial equipment with RS485/Modbus.
  The remote device communicates via Modbus/RTU, while the bridge transfers the data through the ZigBee network to a 4-noks gateway. The gateway can then make the data available to a PLC, PC, SCADA or supervisory system.

🧩 Compatibility

The ZR-BR-485-EM is designed to work with 4-noks ZC-GW gateways and third-party devices equipped with Modbus/RTU over RS485.
4-noks family documentation explicitly shows the bridge being used with:

• generic I/O devices;
• power meters;
• controllers;
• other third-party Modbus devices.
  For operation, it is necessary to verify the Modbus address, serial parameters, RS485 wiring and compatibility with the ZigBee gateway being used.

📡 Communication Architecture

Typical configuration:
Modbus RS485 Device → ZR-BR-485-EM → ZigBee Network → 4-noks Gateway → PLC / PC / SCADA
The 4-noks gateway manages the ZigBee network and provides the connection to the Modbus system; the bridge therefore allows remote Modbus devices to be integrated into the wireless network.

⚠️ Typical Faults and Symptoms

A bridge problem may cause:

• loss of communication with the Modbus device;
• Modbus device unreachable from the gateway;
• intermittent communication;
• Modbus request timeouts;
• absence of data in the SCADA/PLC system;
• loss of ZigBee connection;
• failure to route messages;
• device power supply failure.
  It is important to distinguish a bridge fault from problems with power supply, RS485 wiring, Modbus configuration, ZigBee gateway or radio link quality.

🚨 Possible Associated Errors

The ZR-BR-485-EM does not generate a universal list of error codes like an inverter. Faults normally appear as communication problems:

• Modbus timeout
• slave device unreachable;
• loss of ZigBee node;
• intermittent communication;
• no response to requests;
• data not updated in the supervisory system.
  Diagnosis must therefore be performed by checking the RS485 connection, ZigBee network and gateway separately.

🛠️ Common Services in Case of Failure

• Power supply verification.
• RS485 interface testing.
• Modbus communication check.
• ZigBee radio section inspection.
• Antenna check.
• Gateway connection verification.
• Network parameter configuration/check.
• Communication testing with the Modbus device.

🛠️ Applications

The bridge can be used to connect Modbus/RS485 equipment wirelessly in:

• industrial automation;
• energy monitoring systems;
• photovoltaic installations;
• energy measurement systems;
• BMS;
• SCADA systems;
• building automation;
• supervisory and control systems.
  4-noks documentation specifically shows the platform being used for energy monitoring, PLC, SCADA, BMS and third-party Modbus devices.

🛡️ Product Condition

new product. The device is shown with antenna, power supply and original packaging.
The packaging shows storage-related signs due to age.

📦 Package Contents

• 1 × 4-noks ZR-BR-485-EM
• 1 × external antenna
• 1 × power supply
• 1 × original packaging, as shown in the photographs.

🟢 Summary

The 4-noks ZR-BR-485-EM is a ZigBee – Modbus RS485 Bridge designed to connect Modbus/RTU devices equipped with RS485 to a ZigBee network. It allows PLCs, PCs, SCADA systems or supervisory systems connected to the gateway to communicate with remote Modbus equipment without running a direct RS485 connection to the supervision point. It supports 12–24 V AC/DC power supply, an external antenna and routing functions within the ZigBee network.
⚠️ Note: Compatibility must be verified with the 4-noks gateway and with the parameters of the connected Modbus/RS485 device.