PLC Optically Isolated USB Adapter for Siemens S7-200/300/400
PLC Optically Isolated USB Adapter for Siemens S7-200/300/400
PLC Optically Isolated USB Programming Adapter – Compatible with Siemens S7-200/300/400
Take your industrial PLC programming to the next level with this professional-grade optically isolated USB adapter. Engineered for demanding factory environments, this adapter provides full photoelectric (optocoupler) isolation between your PC and PLC, ensuring stable, interference-free communication even in the presence of variable frequency drives (VFDs), motor starters, and other noise-generating industrial equipment.
Why Optical Isolation Matters in Industrial Settings
Industrial environments are notorious for electrical noise and transient surges. This adapter's optocoupler design uses light — not direct electrical connection — to transfer signals between the USB and RS485 interfaces. The result: unidirectional signal transmission, zero feedback from output to input, strong electromagnetic immunity, and rock-solid system stability. Both USB and RS485 ports are also equipped with dedicated surge protection circuits and support hot-swapping for added convenience.
Key Features
- Full Optical Isolation: Photoelectric signal isolation (optocoupler) across all communication lines for maximum stability
- Wide PLC Compatibility: Works with Siemens S7-200, S7-300, and S7-400 series PLCs, as well as Siemens HMIs and touch panels (TP170/177/270, OP25/35/77, MP177/270/277B, and more)
- Multi-Protocol Support: Supports PPI, MPI, and DP multi-master communication modes
- Hot-Swap Ready: USB and RS485 ports support hot-swapping for flexible field deployment
- Long-Distance Communication: RS485 side supports cable runs up to 1,000 meters at 187.5 Kbps
- Plug-and-Play (S7-300 V5.5+): No virtual COM port or driver installation required — simply select the USB interface directly in STEP7 V5.5
- Rugged Construction: Industrial-grade flame-retardant PC+ABS alloy plastic housing
- Wide Operating Temperature: -20°C to +75°C for reliable performance across environments
Technical Specifications
| Model | Compatible with 6ES7972-0CB20-0XA0 |
| Cable Length | Approx. 5 meters |
| Interface | USB to 9-pin male connector |
| Voltage | ≤80V |
| MPI Baud Rates | 19.2 Kbps, 187.5 Kbps (auto-adapts to 500 Kbps & 1.5 Mbps for DP master) |
| PPI Baud Rates | 9.6 Kbps, 19.2 Kbps, 187.5 Kbps |
| Software Support | STEP7 V5.2 and later; STEP7 Micro/Win 4.0 and later |
| OS Compatibility | Windows XP, Vista, Windows 7 |
| Material | Flame-retardant PC+ABS alloy plastic |
| Operating Temperature | -20°C to +75°C |
| Country of Origin | Made in China |
Compatible Applications
- Siemens S7-200 / S7-300 / S7-400 PLC programming and monitoring
- Siemens HMI/touch panel communication (TP, OP, MP series)
- Industrial automation, SCADA systems, and factory process control
- Online monitoring and data transmission in noisy electrical environments
Package Contents
- 1 × Optically Isolated USB Programming Adapter (~5m cable)
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Frequently Asked Questions
Q: Is this adapter compatible with Siemens S7-300 and S7-400 PLCs?
A: Yes. This optically isolated USB adapter is fully compatible with Siemens S7-200, S7-300, and S7-400 series PLCs, as well as a wide range of Siemens HMI and touch panel devices. It supports PPI, MPI, and DP multi-master communication protocols.
Q: Do I need to install drivers to use this PLC programming cable?
A: When using Siemens STEP7 V5.5 programming software for S7-300 communication, no driver installation or virtual COM port setup is required — simply select the USB interface directly within the software. For S7-200 use, ensure STEP7 Micro/Win 4.0 or later is installed on your PC.
Q: Why should I use an optically isolated adapter instead of a standard USB adapter?
A: In industrial environments, equipment such as variable frequency drives (VFDs) and power modules can generate electrical interference during startup and shutdown, which may disrupt data transmission. The optocoupler-based isolation in this adapter separates the PC-side and PLC-side circuits using light as the signal medium, protecting both your computer and PLC from damaging transients and ensuring stable, uninterrupted communication.
Q: What is the maximum communication distance supported by this adapter?
A: On the RS485 side at a baud rate of 187.5 Kbps, this adapter supports long-distance communication up to 1,000 meters, making it well-suited for large factory floor deployments.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.