BCNet‑QnA enables Mitsubishi Q2A/Q2AS1/Q3A/Q4A PLCs to connect via Modbus TCP or MC protocol over Ethernet without losing programming port access.
Product Overview
BCNet‑QnA is an Ethernet communication module that mounts on standard DIN rail and links to QnA PLCs via their programming port. Powered by 24 VDC, it integrates MC and Modbus TCP servers, allowing GX Developer, SCADA, KepWare OPC, or custom VB/C# apps to read/write PLC data over Ethernet while preserving the original programming interface. A built-in web server allows configuration and diagnostics via password protection. With support for Modbus FC1/2/3/5/6/15/16 and automatic baud‑rate adjustment, BCNet‑QnA streamlines data collection for production monitoring and industrial IoT systems.
How to Use
- Mount module on 35 mm DIN rail and connect RS‑232/422 port to PLC programming port.
- Supply 24 VDC to power the device.
- Access the web UI via Ethernet to set IP, protocol (MC or Modbus TCP), and login credentials.
- Use MELSOFT (GX Developer) or OPC/SCADA tools with Mitsubishi Ethernet driver to read/write data.
- For Modbus TCP, map PLC memory automatically to holding/input registers.
- Run diagnostics via web page.
Tip: Enable password protection to prevent unauthorized config changes. Firmware updates are available online via Ethernet.
Related Videos
Mitsubishi PLC as Modbus TCP Server: A Quick Tutorial
Frequently Asked Questions (FAQ)
Q1: Does BCNet‑QnA support GX Developer Ethernet functions?
A1: Yes—read/write PLC logic and monitor during RUN via Ethernet OS functions.
Q2: Can I still program the PLC?
A2: Yes—the programming port remains available for GX Developer while BCNet‑QnA uses the same interface.
Q3: Does it auto-detect baud rate?
A3: Yes—the RS‑232/422 port auto-adjusts to PLC communication speed.
Q4: Which protocols are supported?
A4: MC protocol (MELSEC frames) and Modbus TCP (FC1/2/3/5/6/15/16).
Q5: How many clients can connect?
A5: Up to 6 concurrently using different protocols (MC, MELSOFT, Modbus TCP or BCNet‑TCP).
Q6: Is there a web interface?
A6: Yes—with password protection for settings and diagnostics.
Q7: Does it need external power?
A7: Yes—24 VDC required.
Q8: Is firmware upgradeable?
A8: Yes—supports Ethernet-based firmware updates at no extra cost.
Q9: What PLC series are compatible?
A9: Mitsubishi Q2A, Q2AS1, Q3A, Q4A (QnA series).
Q10: What SCADA/OPC software works?
A10: KepWare, MCGS, C-onfiguration king, and any OPC‑capable tool supporting Mitsubishi Ethernet.
User Review Summary
Based on eBay listing and industrial forum feedback, users praise BCNet‑QnA for saving cost compared with Mitsubishi’s RJ71EN71 module, noting easy integration and stable Modbus TCP mapping. One buyer rated it “96% positive” and commended fast delivery from Shenzhen. Some mention initial configuration takes a few trials to map registers accurately.
Comparison with Competing Products
• Mitsubishi RJ71EN71: Official Mitsubishi Ethernet module—fully integrated, OEM warranty, but significantly more expensive. BCNet‑QnA offers similar Ethernet‑MC integration at lower cost.
• LX-MBTCP Gateway: Offers Modbus TCP for various PLC brands but requires separate serial adaptors; BCNet‑QnA is plug-and-play for QnA series.
• DIY Raspberry Pi Modbus Converter: Flexible and low-cost, but has higher complexity and lacks web diagnostic UI—BCNet‑QnA is more industrial-ready and reliable.
Technical Specifications
Size: ~100 × 60 × 25 mm, DIN‑rail mountable
Power: 24 VDC
Ports: 1× RJ45 Ethernet, 2× mini‑DIN (programming ports)
Protocols: Mitsubishi MC, MELSOFT Ethernet, Modbus TCP (FC1/2/3/5/6/15/16), BCNet‑TCP
Clients: Up to 6 concurrent
Features: Web UI, password protection, auto baud, firmware upgrade via Ethernet, Ethernet read/write in RUN
Brand or Manufacturer Info
Beichen Electronics manufactures niche industrial communication devices focused on cost-effective, standards-based networking solutions. Specialty in PLC Ethernet converters with firmware updates and technical support ensures longevity and reliability.
Purchase Recommendations
BeiChen: https://www.beichen.store/bcnet-qna/