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  • New item   -29.35€USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2
    New item   -29.35€USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2 1
    New item   -29.35€USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2 2
    New item   -29.35€USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2 3

    USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2

    Code: CNVT-USB-RS485-V2
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  • Product description

    USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2

    CNVT-USB-RS485-V2 – Sentera Controls USB to Modbus RTU (RS485) converter. On the computer it works as a standard Windows COM port, so Sentera controllers, sensors and modules can be monitored and configured directly from a laptop.

    Key idea:
    This is a service tool for the installer's bag: you arrive at the site, plug the converter into USB, connect to the Modbus line with an RJ45 cable – and see all of the device's registers. You can use your own cables or choose the CNVT-USB-RS485-SET kit.
    Interface
    USB 2.0 (A type) → RS485
    Protocol
    Modbus RTU, 4 800–230 400 b/s
    Power supply
    5 VDC from USB, up to 20 mA
    Scope of delivery
    Converter (1 pc.)

    Operating principle

    The converter is plugged into the computer's USB port and is installed in the system as a standard Windows COM port, and the RJ45 socket is connected with your own UTP cable to a Sentera device or a Modbus RTU (RS485) line. Only contacts 3–4 (A) and 5–6 (/B) are used in the socket, while 1, 2, 7 and 8 are not connected, so the converter does not power the connected device – it is itself powered from USB (5 VDC, up to 20 mA).

    Communication: 2-wire RS485 bus for up to 256 nodes, speed 4 800–230 400 bps, parity none / even / odd, 7 or 8 data bits, 256 B input and output buffers. Two green LEDs indicate transmit (TX) and receive (RX).

    Result – the device registers are visible and editable in 3SModbus or another Modbus program, and the RS485-side protection (±16 kV ESD per HBM; ±8 kV contact / ±30 kV air discharge per IEC 61000-4-2; ±4 kV EFT per IEC 61000-4-4; ±2.5 kV 1.2/50 µs surge per IEC 61000-4-5) allows safer connection to lines already operating on site.

    Benefits CNVT-USB-RS485-V2?
    One inexpensive tool lets you commission, check and reconfigure any Sentera Modbus RTU device on site – without a BMS and without additional power.

    Technical specifications

    Product type USB–Modbus RTU (RS485) converter
    Manufacturer / code Sentera Controls / CNVT-USB-RS485-V2
    Power supply 5 VDC via the USB connector, Imax 20 mA
    USB USB 2.0, A type
    RS485 connection RJ45: 3–4 – A, 5–6 – /B; 1, 2, 7, 8 – not connected
    Bus 2-wire RS485, up to 256 nodes
    Sparta 4 800–230 400 bps
    Parity / data bits none, even, odd / 7 or 8
    Buffers 256 B input, 256 B output
    RS485 protection ±16 kV ESD (HBM); ±8 kV contact, ±30 kV air (IEC 61000-4-2); ±4 kV EFT (IEC 61000-4-4); ±2.5 kV 1.2/50 µs (IEC 61000-4-5)
    Indication Green LED1 – transmit (TX), green LED2 – receive (RX)
    Operating system Installed as a standard Windows COM port
    Dimensions 22.5 × 21 × 42.5 mm
    Protection class IP30 (EN 60529)
    Operating environment -10…+60 °C, 5–85 % rH
    Weight 15 g net
    Compliance LVD 2014/35/EU, WEEE 2012/19/EU, RoHS 2011/65/EU

    Manufacturer documentation

    ✔ Recommended by Elektrotechnikos sprendimai

    Original manufacturer documentation – technical data, wiring diagrams and installation instructions.

    Main functions

    • Virtual COM port – the computer sees the converter as an ordinary serial port – suitable for 3SModbus and other Modbus programs.
    • Power from USB – no additional power supply is needed.
    • Wide choice of baud rate and format – 4 800–230 400 bps, none / even / odd parity, 7 / 8 bits – also communicates with non-Sentera Modbus equipment.
    • TX / RX LED – you can see at a glance whether data is being exchanged with the device.
    • RJ45 socket – connected with the same UTP cable as Sentera PoM devices.
    • Line protection – ESD and overvoltage protection on the RS485 side.

    Where is it used?

    • Commissioning and tuning of Sentera controllers, sensors and modules
    • Setting the Modbus address, baud rate and parity before connecting to the BMS
    • Troubleshooting a Modbus RTU line
    • Firmware update and register reading via 3SModbus
    • Laboratories, training, control panel manufacturing
    • Service visits – quick diagnostics from a laptop
    • Testing non-Sentera Modbus RTU equipment via the COM port

    On-demand operation

    For service engineers.
    A lightweight 15 g converter always in your bag quickly shows whether the problem is in the device or on the Modbus line.
    For the BMS integrator.
    Before integration, it checks the registers, address and communication parameters through a standard COM port.
    For installers with their own UTP cables.
    The customer buys only the converter and does not pay for cables they already have.

    Practical application

    If you already carry UTP cables with RJ45 in your service vehicle, then the CNVT-USB-RS485-V2 is enough: powered from a laptop USB (up to 20 mA), it lets you read a device's registers within minutes, and the TX / RX LEDs immediately show whether the device responds.

    Application guide: how it is used in practice

    CNVT-USB-RS485-V2 is always connected between the computer and a Modbus RTU device – only what you connect to differs:

    Site What is connected Result Installer's note
    Sentera device with an RJ45 socket (-M, -H types) UTP cable RJ45–RJ45 → converter RJ45 The device is visible in the 3SModbus program, parameters can be changed The device needs a separate power supply – the converter does not power it via RJ45
    Device with terminals A, /B (-F, -G, -H types) UTP cable RJ45–bare wire ends → terminals A and /B Communication without an RJ45 socket on the device Check the A and /B polarity – if reversed, there will be no communication
    A working BMS Modbus line The converter is connected to line A, /B Line devices can be monitored and address conflicts found The computer must not send requests together with the BMS master controller
    Control panel manufacturing / test bench Converter + PoM-powered device Devices are pre-addressed and tested in the workshop Give each device a unique Modbus address

    How to choose a USB–Modbus converter

    Scope of delivery Recommended model
    Converter only – UTP cables are already on hand CNVT-USB-RS485-V2 (converter) ← this model
    Converter + 0.5 m USB extension cable + 2 UTP cables (RJ45–RJ45 and RJ45–wires) CNVT-USB-RS485-SET (kit)
    Rule: if you have no UTP cables or work with Sentera devices of different types (RJ45 and terminals) – choose CNVT-USB-RS485-SET; if you make the cables yourself – CNVT-USB-RS485-V2 is enough.
    When to choose another solution: for permanent remote monitoring over the internet instead of a computer – Sentera internet gateways DIG-M-2, SIG-M-2, DIGWM or SIGWM (SenteraWeb).

    Pros

    • USB-powered
    • Windows COM port – compatible with common Modbus software
    • Wide choice of baud rate and parity
    • TX / RX indication
    • RS485 protection against ESD and overvoltage
    • Small and lightweight

    Cons / limitations

    • It does not power the connected device through the RJ45 – the device needs its own power supply
    • Galvanic isolation is not specified in the datasheet
    • IP30 – indoors and for use with a computer only
    • Intended for configuration and diagnostics; for permanent remote monitoring – the DIG-M-2 or DIGWM internet gateway
    • UTP cables are not included in the kit – the complete set is the CNVT-USB-RS485-SET

    Safety and installation notes

    • When connecting to live equipment, follow the site's electrical safety requirements; connection to the terminals is to be made by a qualified specialist.
    • When connecting the RJ45-to-wire cable, check the A and /B polarity.
    • Use in an environment of -10…+60 °C and 5–85 % rH.
    • A single Modbus segment must not have two master devices at the same time.

    Quick selection guide

    USB 2.0
    Modbus RTU
    RS485
    RJ45
    IP30
    Suitable when you need:
    • to commission and tune Sentera Modbus RTU devices from a computer;
    • to set the Modbus address and communication parameters;
    • to diagnose RS485 line communication problems.
    Check before use:
    • whether the device has an RJ45 socket or terminals A, /B – the cable depends on it;
    • whether the device has its own power supply;
    • whether the PC has Windows and a free USB-A port.
    Important reminder: CNVT-USB-RS485-V2 is a configuration and diagnostic tool – for permanent remote monitoring use a Sentera internet gateway.

    FAQ

    Does the transmitter power the connected device?
    No, RJ45 contacts 1, 2, 7 and 8 are not connected, so the device needs its own power supply.
    Which software should I use?
    Compatible with Sentera 3SModbus or any Modbus RTU software running through a Windows COM port.
    How many devices can be seen on one line?
    The RS485 bus supports up to 256 nodes, and each device must have a unique Modbus address.
    Are the cables included in the kit?
    No, the V2 is supplied without cables, and the complete cable set is in the CNVT-USB-RS485-SET kit.
    How do I connect to a device with terminals A and /B?
    Use a UTP cable with an RJ45 plug on one end and bare wire ends on the other, connecting the 3–4 contact pair to A and the 5–6 pair to /B.
    How can I see whether communication is taking place?
    Green LED1 indicates transmit (TX), and green LED2 – receive (RX).

    USB–Modbus RTU (RS485) converter | USB 2.0 | RJ45 | 5VDC via USB | IP30 | Sentera Controls | CNVT-USB-RS485-V2

    Sentera CNVT-USB-RS485-V2 – a USB to Modbus RTU (RS485) converter for configuring and diagnosing Sentera devices: Windows COM port, 4 800–230 400 b/s, RJ45, USB-powered, IP30.

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.
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