OPCB-221B Operating Manual

This Operating Manual explains the design, safety requirements, operating rules, and maintenance procedures for the Overvis OPCB-221B controller.

The Quality Management System of the device designing and production complies with the requirements of ISO 9001:2015.

Purpose

The Controller OPCB-221B (hereinafter referred to as the “Controller”, “Product”, “Device”, or “OPCB-221B”) provides MODBUS communication between clients and servers in TCP networks (Internet) and between devices in the RS-485 interface.

OPCB-221B is used to remotely monitor and control the operation of:

• Refrigeration controllers
• HVAC systems controllers
• Agricultural smart devices
• Power network relays, meters, and other electrical equipment
• Industrial IoT devices
• Industrial sensors and meters
• Other MODBUS-compatible electronics

OPCB-221B Features

• MODBUS RTU/TCP converter
• Built-in Overvis cloud support (www.overvis.com)
• Serves as TCP server or client, MODBUS RTU master or slave
• RS-485 network extension
• MODBUS ASCII mode support
• Supports LAN and/or Wi-Fi connection
• Optional 3G/LTE connection using an external USB modem
• Wi-Fi Access Point mode
• Web interface, accessible from the local network, via Wi-Fi Access Point, or using Overvis cloud connection
• Remote configuration (using MODBUS or web interface)
• RS-485 network settings: baud rate, parity, response timeout
• Supports multiple RS-485 networks
• MODBUS request debugging tools
• Automatic or manual firmware updates
• HTTP API

Terms and Abbreviations

Term	Definition
Wi-Fi station	A device connected to another device through Wi-Fi (access point)
Wi-Fi access point	A device enabling connection to it through Wi-Fi
DHCP	A protocol enabling network units to automatically obtain TCP/IP parameters (IP address)
HTTP	The transmission protocol for web pages and other data using client-server technology
IP (address)	The address of the unit, which is unique within one network that is operated according to IP protocol
IPv4	A four-byte IP address
MAC (address)	The address used in network transmissions for device identification. It is typically globally unique
MAC-48	A six-byte MAC address
MODBUS	The standard packet communication protocol based on the client-server technology intended for industrial electronic devices
MODBUS RTU	The devices linking protocol, where the packet is transmitted byte by byte
MODBUS ASCII	The devices linking protocol, where the packet is transmitted in ASCII characters
MODBUS TCP	MODBUS packet transmission protocol according to TCP/IP standard
WEB	The server documents access system used on the Internet
Wi-Fi	A family of standards for data transmission via radio channels

Complete Set

Table 1 – Product Set

Name	Quantity
1. Controller OPCB-221B (with installed MicroSD memory card and integrated Wi-Fi antenna, 3 dBm)	1
2. USB/RS-485 extension module (supporting up to 32 connected RS-485 devices)	1
3. Power supply with USB Type-A output and DC Plug cable	1
4. Ethernet cable	1
5. Operation manual with Cloud Registration sticker	1

Overall Mounting Dimensions and Controls

Figure 1 – OPCB-221B Overall and Mounting Dimensions

Connectors and Controls

1. “EXT1” connectors: 2 USB Type-A connectors for connecting additional modules (e.g., RS-485 / RS-232 serial interface converters)
2. “ETH” connector: 8P8C/RJ45 for wired connection to the local Ethernet network
3. “EXT2” connector: USB Type-A connector for connecting additional modules (e.g., RS-485 / RS-232 serial interface converters)
4. “PWR” connector: DC Plug for connecting a 5V DC power source with a power of at least 9W
5. “HDMI” connector: HDMI output (not used)
6. “AUX” connector: Audio output (not used)
7. “MEM” slot: MicroSD card slot for accessing the pre-installed memory card

Technical Specifications

OPCB-221B Controller

Table 2 – OPCB-221B Controller Main Technical Specifications

Parameter	Value
Power supply voltage DC, V	5.0
Motherboard	Orange Pi PC Plus 1G RAM
TCP networks link interface	Ethernet, Wi-Fi
Ethernet communication interface	10BASE-T/100BASE-T (twisted pair)
Wi-Fi frequency, GHz	2.4
Supported Wi-Fi standards	IEEE 802.11 b/g/n
Supported TCP/IP protocols	MODBUS TCP, HTTP, DNS, DHCP, WireGuard
Maximum number of incoming connections via MODBUS TCP protocol	4
Maximum number of outgoing connections via MODBUS TCP protocol	4
Maximum number of serial interfaces	3 (through individual USB ports)
Supported serial interface protocols	MODBUS RTU, MODBUS ASCII
Supported serial MODBUS modes	Master, Slave
Maximum number of connected MODBUS devices	255
Built-in servers	MODBUS TCP, HTTP
Ready time at power up, s, no more than	60
Current consumption, mA, max	2000
Weight, kg, no more than	0.200
Overall dimensions HxBxL, mm, no more than	99 × 82 × 36
Product designation	Switchgear and control equipment
Rated operating condition	Continuous
Degree of protection	IP30
Electric shock protection class	III
Climatic design version	NF 3.1
Permissible contamination level	II
Galvanic insulation, kV: Power connector	–
Galvanic insulation, kV: Ethernet connector	1.5
Galvanic insulation, kV: USB	–
Installation (mounting)	Panel

Standards Compliance:

• The product meets the requirements of the following standards: EN 60947-1; EN 60947-6-2; EN 55011; EN 61000-4-2
• The product retains its functionality in any position in space
• Case material: Aluminum
• Harmful substances in amounts exceeding maximum permissible concentrations are absent

USB-RS485 Extension Module

Table 3 – USB-RS485 Extension Module Technical Specifications

Parameter	Value
Communication speed, bps	300-921600
Direction control	Hardware automatically determines and controls data transmission direction
Transmission distance (at low speed)	About 1200 meters
Transmission mode	Up to 32 nodes in point pairs (repeaters are recommended for more than 16 nodes)
Balance resistance	Onboard 120 Ohm, jumper-connectable
Current consumption, mA, max	50
Interface protection	Provides 600W lightning protection, surge and 15kV static protection
Galvanic insulation	Present
Weight, kg, no more than	0.010
Overall dimensions HxBxL, mm, no more than	15×18×63
Cross-section of wires to be connected, mm²	0.13 – 0.82
Tightening torque of terminal screws, N·m	0.3
Degree of protection	IP20

Power Adapter

Table 4 – Power Adapter Technical Specifications

Parameter	Value
Input AC voltage range, V	100-240
Input AC current, mA	500
Input AC frequency range, Hz	50/60
Output voltage DC, V	5.0
Output current DC, mA, max	3000
AC inlet	EU 2 pin plug
DC connector	USB Type-A
Weight, kg, no more than	0.065
Overall dimensions HxBxL, mm, no more than	80×30×75
Degree of protection	IP20
Electric shock protection class	II
Insulation voltage	Input/Output to outer case, 500VDC, greater than 10MΩ
Input to output withstand voltage	AC 3kV / 10mA, 3s

Operating Conditions

The product is intended for operation under the following conditions:

• Ambient temperature: -10 to +55 °C
• Atmospheric pressure: 84 to 106.7 kPa
• Relative humidity (at +25 °С): 30 to 80%

Do not operate OPCB-221B:

• Under significant vibrations and shock
• In high humidity environments
• In aggressive environments containing acids, alkalis, etc., or with strong contaminants (grease, oil, dust, etc.)

General Instructions

ATTENTION

ALL CONNECTIONS MUST BE MADE WITH THE PRODUCT DE-ENERGIZED.

Errors during installation may damage the product and connected devices.

When connecting to the RS-485 bus, use a twisted pair cable, cat. 1 or higher. Strip the ends of insulation by 4±0.5 mm and tighten with bushing tips. A shielded grounded cable is recommended.

DO NOT LEAVE ANY BARE WIRE PROTRUDING BEYOND THE TERMINAL BLOCK.

For reliable contact, tighten the terminal screws with the force indicated in the technical characteristics table.

When connecting to Ethernet, use the supplied cable, or a twisted pair cable of cat. 5e with an 8P8C (RJ45) plug.

When fixing the wires, avoid mechanical damage, twisting, or wearing down the insulation of wires.

Connection

Before starting:

1. Unpack and inspect the product for damage after transportation. If any damage is found, contact the supplier or the manufacturer.
2. Before connecting to the power supply, keep the product under operating conditions for two hours (in case of possible condensation on the elements).
3. Carefully study the operating manual.
4. If you have any questions about the installation of the product, please contact technical support.

Figure 2 – Product Connection Diagram

Connect OPCB-221B according to Figure 2, in the following order:

1. Using a twisted-pair cable of category 1 or higher, connect the terminal block of the RS-485 module to the serial interface bus (or directly to a device with this interface).

   Note

   Contact “A” is for the non-inverted signal (D+), and contact “B” is for the inverted signal (D-).

2. If the product should have access to the Internet or LAN, use the Ethernet connection cable (included in the package) or a twisted pair cable of cat. 5e with an 8P8C (RJ45) plug to connect the “ETH” connector (8P8C/RJ45) to the local network or computer.

3. Ensure the memory card is present in the “MEM” slot (installed by the manufacturer).

4. Connect the RS-485 module to one of the “EXT1” or “EXT2” (USB Type-A) connectors.

5. Connect the power unit (included) to the “PWR” (DC Plug) connector.

6. Optionally: Secure the USB connections with plastic cable ties to avoid accidental disconnection.

7. Connect the power unit to the power supply network (220-240VAC, 50Hz).

OPCB-221B Operation

General Information

OPCB-221B has a 32-bit processor running a POSIX-compliant OS (Armbian). It routes traffic between the USB extension modules, such as serial RS-485 / RS-232 interfaces (MODBUS RTU/ASCII protocols), and Ethernet/Wi-Fi LAN interfaces (MODBUS TCP protocol), possibly routed further to the Internet.

OPCB-221B has a built-in web interface that can be used for configuration.

OPCB-221B can connect to a cloud server for remote monitoring and configuration of the product and connected devices.

OPCB-221B provides a Wi-Fi Access Point (hotspot) to simplify the initial setup. Wi-Fi Access Point can be disabled in the settings.

OPCB-221B stores the operating system and data on the pre-installed microSD memory card. Removing or replacing the memory card will render the product inoperable.

Power Up and Reboot Sequence

After powering up, OPCB-221B loads the operating system and sets up the communication interfaces. This process usually takes up to 1 minute.

With an internet connection provided, OPCB-221B automatically connects to the cloud server if allowed in the settings. By default, unconfigured OPCB-221B creates a Wi-Fi access point with SSID “OPCB_XXXXXX” (where XXXXXX are the last 6 characters of the device’s MAC) and a password specified on the Registration sticker (attached to this manual).

Soft Reboot: Use the web interface by pressing the “Reboot device” button on the “Control” page. This will finish all ongoing operations, store the data, and reboot the device within 1 minute.

Hard Reboot: Turn off the power by unplugging the device, wait 5 seconds, and then turn the power back on.

Operation via HTTP

OPCB-221B provides an HTTP web interface and HTTP REST API for web applications. OPCB-221B accepts HTTP connections via Ethernet or Wi-Fi interfaces on TCP port 80.

To access the HTTP web interface:

1. Connect to the OPCB-221B Wi-Fi access point with a PC or mobile device and open the following URL in the browser: http://192.168.4.1/

2. Alternatively, using any PC or mobile device in the local network, open the IP address of the OPCB-221B in the browser. The OPCB-221B IP address can usually be found by accessing the local network router interface.

The default username for the web interface is “admin” with the password specified on the Registration sticker (attached to this manual).

OPCB-221B Operation via MODBUS (TCP/RTU/ASCII)

OPCB-221B receives MODBUS TCP requests via Ethernet or Wi-Fi interfaces and transmits them in MODBUS RTU or MODBUS ASCII format over the serial interface. Responses are converted to MODBUS TCP and sent back to the requesting side.

OPCB-221B can also be configured to receive MODBUS RTU or MODBUS ASCII requests via the serial interface and transmit them in MODBUS TCP format to specified IP addresses via Ethernet or Wi-Fi interfaces. In this case, the responses (converted to the request protocol) are sent back to the serial line.

Connections from a PC or mobile device can be made using any software MODBUS TCP clients.

MODBUS registers of the OPCB-221B are configurable in the web interface on the “Connections” page in the section “OPCB Modbus access.”

MODBUS routing between the connected devices is configured in the web interface on the “Connections” page in the section “Routing.”

OPCB-221B Operation Using the Overvis Cloud Server

OPCB-221B can establish connections to the Overvis cloud server using any interface with Internet access. OPCB-221B communicates with the Overvis cloud using an Overvis VPN connection, which provides full encryption of traffic between the device and the Overvis cloud server.

Overvis VPN cloud connection is enabled by default and can be disabled in the settings.

The cloud operation can be configured and managed by creating an account on the Overvis cloud: https://www.overvis.com/

Registration Sticker Information

The OPCB-221B product set includes an Overvis Cloud registration sticker. Sticker information includes:

• Model of the device (OPCB-221B)
• MAC address of the LAN interface
• Private key: The unique private key of the device for Overvis VPN access, also used as a unique registration code for the Overvis cloud. This key is needed to restore the device license in case of firmware reflashing
• PIN code: The unique PIN code for quick identification of the device on the Overvis cloud
• Wi-Fi SSID and password for the initial connection to the Wi-Fi Access Point
• Default username and password for web interface access
• Quick setup link (with QR-code) for easy connection to the Overvis cloud

Access the link on the sticker and follow the instructions on the Overvis website to set up the device cloud operation and access the OPCB-221B interface through the Overvis cloud.

Factory Reset

A partial factory reset can be performed in one of the following ways:

Using a control key USB flash drive: Write an empty file or an empty folder named "RESET_CONF" to a USB flash drive, then connect it to one of the “EXT1” or “EXT2” slots to reset the settings to the factory defaults. The reset may take up to 30 seconds; the USB flash drive can be disconnected afterward.

Through the web interface: Use the “Control” page in the web interface.

Firmware Update

Device firmware is updated continuously by the manufacturer. By default, the new version is installed automatically after the device is powered on or within 24 hours of operation. Automatic updates guarantee the backward compatibility of all OPCB-221B functions. Releases without backward compatibility require manual installation.

The currently installed version is displayed in the OPCB-221B web interface. The changelog for each version is available here: https://github.com/overvis/opcb-release/blob/opcb/CHANGELOG.md

Manual Firmware Update and Full Factory Reset

A manual update requires a full factory reset by uploading a new firmware image to the SD memory card. All current firmware images can be found on the release page: https://github.com/overvis/opcb-release/releases

Initial Setup

The device can be configured via the web interface. Configuration parameters are stored in a file on the SD memory card.

Note

Some settings require a soft reboot. Clients may lose the connection and have to reconnect.

Step 1: Access the Web Interface

After the device is plugged in and operational, access the web interface by connecting to the Wi-Fi Access Point or using the local network.

By default, an unconfigured OPCB-221B creates a Wi-Fi access point with SSID “OPCB_XXXXXX” (where XXXXXX are the last 6 characters of the device’s MAC) and a password specified on the Registration sticker (attached to this manual).

Connect to the OPCB-221B Wi-Fi access point with a PC or mobile device and open the following URL in the browser: http://192.168.4.1/

Step 2: Log In

Log in to the web interface using the default username “admin” and the password specified on the Registration sticker (attached to this manual).

Step 3: Quick Setup

After logging in, the quick setup page will be displayed. If the device was configured previously and reconfiguration is needed, the quick setup page can be accessed from the drop-down drawer in the header under the logo.

Step 4: Connect to Overvis Cloud

After the initial setup, the device will connect to the internet using the specified settings and will be available in the Overvis cloud.

Access the link on the sticker and follow the instructions on the Overvis website to set up the device cloud operation and access the OPCB-221B interface through the Overvis cloud.

ATTENTION

Ensure the Internet connection is correctly configured before disabling the Wi-Fi access point. Otherwise, an incorrect configuration may prevent any communication with the device, which can only be fixed with a factory reset.

Safety Precautions

To ensure the product’s safe operation, it is strictly forbidden to:

• Carry out installation works and maintenance without disconnecting the product from the mains
• Open and repair the product without professional help
• Operate the product with mechanical damages to the housing

Water penetration on terminals and internal elements of the product is not allowed.

During operation and maintenance, the regulatory document requirements must be met, namely:

• Regulations for Operation of Consumer Electrical Installations
• Safety Rules for Operation of Consumer Electrical Installations
• Occupational Safety in Operation of Electrical Installations

Danger

LIQUID INGRESS ON TERMINALS AND INTERNAL ELEMENTS OF THE DEVICE IS UNACCEPTABLE.

Maintenance

WHEN MAINTAINING, THE PRODUCT AND DEVICES CONNECTED TO IT MUST BE DISCONNECTED FROM THE POWER SUPPLY.

Maintenance of the product should be performed by qualified technicians.

Recommended frequency of maintenance is every six months.

Procedure

1. Check the reliability of wire connections; tighten if necessary
2. Check the reliability of USB connections; fix them with plastic clamps if needed
3. Visually inspect the integrity of the housing. In case of damage, take the product out of service and send it for repair
4. If needed, clean the housing of the product with a dry cloth

Do not use abrasives or solvents for cleaning.

Service Life and Manufacturer Warranty

Parameter	Value
Service lifetime of the product	10 years
Shelf life	3 years
Warranty period	3 years from the date of sale

At the end of its service life, please contact the manufacturer.

During the warranty period (in case of failure), the manufacturer repairs the product free of charge.

Caution

IF THE PRODUCT HAS NOT BEEN USED IN ACCORDANCE WITH THE REQUIREMENTS OF THIS OPERATION MANUAL, THE USER WILL LOSE THE RIGHT TO WARRANTY SERVICE.

Warranty service is performed at the place of purchase or by the manufacturer.

Post-warranty maintenance of the product is performed by the manufacturer at current rates.

Before sending the product for repair, it must be packed in the factory or other packaging that prevents mechanical damage.

If returning the product or submitting it for warranty (post-warranty) service, please state in detail the reason for return in the complaint information field.

Transportation and Storage

The product in its original packaging is permitted to be transported and stored at temperatures ranging from -45 to +60 °C and with relative humidity of no more than 80%. During transportation, the product should be protected from mechanical damage.

Manufacturer Contact Information

NOVATEK-ELECTRO LTD.

Ukraine, 65007, Odessa, Admirala Lazareva str. 59

• Tel: +38(048)738-00-28
• Tel/Fax: +38(048)234-36-73
• Web: http://www.novatek-electro.com